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The Oregon Administrative Rules contain OARs filed through March 15, 2014
 
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OREGON HEALTH AUTHORITY,
PUBLIC HEALTH DIVISION

 

DIVISION 61

PUBLIC WATER SYSTEMS

SCROLL DOWN TO VIEW OARs 333-061-0005 through 333-061-0032

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333-061-0005

Purpose

The purpose of these rules is to provide a basis for implementing the Oregon Drinking Water Quality Act of 1981, enacted to assure safe drinking water at all water systems which serve the public, and to promote coordination between the programs for supervising water systems which are conducted by the Authority and the U.S. Environmental Protection Agency.

Stat. Auth.: ORS 448.131
Stats. Implemented: ORS 448.123 & 448.273
Hist.: HD 106, f. & ef. 2-6-76; HD 17-1981(Temp), f. & ef. 8-28-81; HD 4-1982, f. & ef. 2-26-82; Renumbered from 333-042-0200, HD 2-1983, f. & ef. 2-23-83; HD 9-1989, f. & cert. ef. 11-13-89; PH 7-2010, f. & cert. ef. 4-19-10

333-061-0010

Scope

(1) These rules apply to all public water systems providing piped water for human consumption as defined by the Act.

(2) These rules also apply to all public water systems providing water for human consumption through constructed conveyances other than pipes after Aug. 5, 1998 to at least 15 service connections or that regularly serves at least 25 individuals daily at least 60 days of the year. A water system which meets any of the following “service connection” exclusion criteria and thereby reduces the number of service connections to fewer than 15 and serving fewer than 25 individuals is not a Public Water System:

(a) Water provided by the supplier to the connection is not used for human consumption;

(b) Alternative water (i.e. bottled water, hauled water, or other source) meeting State and Federal water quality standards, as prescribed in OAR 333-061-0030 or 21CFR165, is provided by the supplier to the connection for drinking and cooking;

(c) Treated water meeting State standards, as prescribed in OAR 333-061-0030, applied centrally or at point-of-entry is provided by the supplier, pass-through entity or user to the connection for drinking, cooking and personal hygiene.

(3) These rules do not apply to:

(a) A public water system that:

(A) Consists only of distribution and storage facilities and does not have any source or treatment facilities installed to comply with the maximum contaminant levels covered by these rules; and

(B) Obtains all of its water from, but is not owned or operated by, a public water system to which these rules apply; and

(C) Does not sell water directly to any person; and

(D) Is not a carrier which conveys passengers in interstate commerce.

(b) An irrigation district in existence prior to May 18, 1994, that provides primarily agricultural service through a piped water system to at least 15 service connections or serving at least 25 individuals daily at least 60 days of the year with only incidental residential or similar use, and where all of the connections comply with the alternative or treated water exclusions prescribed in subsections (2)(b) or (c) of this rule.

(c) A public water system that distributes water through submeters if that water system:

(A) Receives all of its water from, but is not owned by, another public water system; and

(B) Consists only of distribution and storage facilities and where all such facilities and all submeters are located on a single parcel of property, and the water system does not have any source or treatment facilities installed to comply with the maximum contaminant levels covered by these rules.

Stat. Auth.: ORS 448.131
Stats. Implemented: ORS 448.131
Hist.: HD 106, f. & ef. 2-6-76; HD 17-1981(Temp), f. & ef. 8-28-81; HD 4-1982, f. & ef. 2-26-82; Renumbered from 333-042-0201, HD 2-1983, f. & ef. 2-23-83; HD 20-1983, f. 10-20-83, ef. 11-1-83; HD 9-1989, f. & cert. ef. 11-13-89; OHD 3-2000, f. 3-8-00, cert. ef. 3-15-00; PH 33-2004, f. & cert. ef. 10-21-04; PH 7-2010, f. & cert. ef. 4-19-10

333-061-0015

Adoption by Reference

All standards, listings and publications referred to in these rules are, by those references, made a part of these rules as though fully set forth. Copies are available from the Authority.

Stat. Auth.: ORS 448.131
Stats. Implemented: ORS 448.131
Hist.: HD 106, f. & ef. 2-6-76; HD 17-1981(Temp), f. & ef. 8-28-81; HD 4-1982, f. & ef. 2-26-82; Renumbered from 333-042-0202, HD 2-1983, f. & ef. 2-23-83; HD 9-1989, f. & cert. ef. 11-13-89; PH 7-2010, f. & cert. ef. 4-19-10

333-061-0020

Definitions

As used in these rules, unless the context indicates otherwise:

(1) "Act" means the Oregon Drinking Water Quality Act of 1981 (ORS 448.115-448.990 as amended).

(2) "Action Level" means the concentration of lead or copper in water which determines, in some cases, the treatment requirements that a water system is required to complete.

(3) "Administrator" means the Director of the Oregon Health Authority or his/her designee.

(4) "Analytical Run" means the process during which a set of analytical drinking water samples along with an appropriate number of blanks, matrix spikes, or quality control samples are analyzed according to National Environmental Laboratory Accreditation Conference (NELAC) requirements to determine the presence, absence, or concentration of a specific target analyte or analytes. An analytical run is complete when the instrument performing the sample analysis generates a report of the sample analysis.

(5) "Approval" or "Approved" means approved in writing.

(6) "Approved Air Gap (AG)" means a physical separation between the free-flowing discharge end of a potable water supply pipeline and an open or non-pressurized receiving vessel. An "Approved Air Gap" shall be at least twice the diameter of the supply pipe measured vertically above the overflow rim of the vessel and in no case less than 1 inch (2.54 cm), and in accord with Oregon Plumbing Specialty Code.

(7) "Approved Backflow Prevention Assembly" means a Reduced Pressure Principle Backflow Prevention Assembly, Reduced Pressure Principle-Detector Backflow Prevention Assembly, Double Check Valve Backflow Prevention Assembly, Double Check-Detector Backflow Prevention Assembly, Pressure Vacuum Breaker Backsiphonage Prevention Assembly, or Spill-Resistant Pressure Vacuum Breaker Backsiphonage Prevention Assembly, of a make, model, orientation, and size approved by the Authority. Assemblies listed in the currently approved backflow prevention assemblies list developed by the University of Southern California, Foundation for Cross-Connection Control and Hydraulic Research, or other testing laboratories using equivalent testing methods, are considered approved by the Authority.

(8) "Aquifer" means a water saturated and permeable geological formation, group of formations, or part of a formation that is capable of transmitting water in sufficient quantity to supply wells or springs.

(9) "Aquifer Parameter" means a characteristic of an aquifer, such as thickness, porosity or hydraulic conductivity.

(10) "Aquifer Test" means pumping a well in a manner that will provide information regarding the hydraulic characteristics of the aquifer.

(11) "Area of public health concern" means an area of the state with a confirmed presence of groundwater contaminants likely to cause adverse human health effects.

(12) "Atmospheric Vacuum Breaker (AVB)" means a non-testable device consisting of an air inlet valve or float check, a check seat and an air inlet port(s). This device is designed to protect against a non-health hazard or a health hazard under a backsiphonage condition only. Product and material approval is under the Oregon Plumbing Specialty Code.

(13) “Authority” means the Oregon Health Authority.

(14) "Auxiliary Water Supply" means any supply of water used to augment the supply obtained from the public water system, which serves the premise in question.

(15) "Average Groundwater Velocity" means the average velocity at which groundwater moves through the aquifer as a function of hydraulic gradient, hydraulic conductivity and porosity.

(16) "AWWA" means the American Water Works Association.

(17) "Backflow" means the flow of water or other liquids, mixtures, or substances into the distributing pipes of a potable supply of water from any sources other than its intended source, and is caused by backsiphonage or backpressure.

(18) "Backflow Preventer" means a device, assembly or method to prevent backflow into the potable water system.

(19) "Backflow Prevention Assembly" means a backflow prevention assembly such as a Pressure Vacuum Breaker Backsiphonage Prevention Assembly, Spill-Resistant Pressure Vacuum Breaker Backsiphonage Prevention Assembly, Double Check Valve Backflow Prevention Assembly, Double Check-Detector Backflow Prevention Assembly, Reduced Pressure Principle Backflow Prevention Assembly, or Reduced Pressure Principle-Detector Backflow Prevention Assembly and the attached shutoff valves on the inlet and outlet ends of the assembly, assembled as a complete unit.

(20) "Backpressure" means an elevation of pressure downstream of the distribution system that would cause, or tend to cause, water to flow opposite of its intended direction.

(21) "Backsiphonage" means a drop in distribution system pressure below atmospheric pressure (partial vacuum), that would cause, or tend to cause, water to flow opposite of its intended direction.

(22) “Bag filter” means a pressure-driven separation device that removes particulate matter larger than one micrometer using an engineered porous filtration media. It is typically constructed of a non-rigid, fabric filtration media housed in a pressure vessel in which the direction of flow is from the inside of the bag to the outside.

(23) “Bank Filtration” means a water treatment process that uses a horizontal or vertical well to recover surface water that has naturally infiltrated into groundwater through a river bed or bank(s). Infiltration is typically enhanced by the hydraulic gradient imposed by a nearby pumping water supply.

(24) "Best Available Technology" or "BAT" means the best technology, treatment techniques, or other means which the EPA finds, after examination for efficacy under field conditions and not solely under laboratory conditions, are available (taking cost into consideration).

(25) "Bore-Sighted Drain to Daylight" means an unrestricted straight-line opening in an enclosure that vents to grade, and is sized and constructed to adequately drain the full flow discharge from a reduced pressure principle backflow prevention assembly thus preventing any potential for submersion of the assembly.

(26) "Bottled Water" means potable water from a source approved by the Authority for domestic use which is placed in small, easily transportable containers.

(27) "Calculated Fixed Radius" means a technique to delineate a wellhead protection area, based on the determination of the volume of the aquifer needed to supply groundwater to a well over a given length of time.

(28) “Cartridge filter” means a pressure-driven separation device that removes particulate matter larger than one micrometer using an engineered porous filtration media. It is typically constructed of rigid or semi-rigid, self-supporting filter elements housed in a pressure vessel in which flow is from the outside of the cartridge to the inside.

(29) “Certificate,” for the purposes of OAR 333-061-0210 through 0290, means a certificate of competency issued by the Authority stating that the operator meets the requirements for a specific operator classification and level.

(30) "CFR" means the Code of Federal Regulations. Specifically, it refers to those sections of the code which deal with the National Primary and Secondary Drinking Water Regulations.

(31) "Check Valve" means a valve, which allows flow in only one direction.

(32) "Coagulation" means a process using coagulant chemicals and mixing by which colloidal and suspended materials are destabilized and agglomerated into floc.

(33) "Coliform-Positive" means the presence of coliform bacteria in a water sample.

(34) “Combined distribution system” means the interconnected distribution system consisting of the distribution systems of wholesale water systems and of the purchasing water systems that receive finished water.

(35) "Community Water System" means a public water system that has 15 or more service connections used by year-round residents, or that regularly serves 25 or more year-round residents.

(36) "Compliance Cycle" means the nine-year calendar year cycle during which public water systems must monitor. Each compliance cycle consists of three three-year compliance periods. The first calendar year cycle begins January 1, 1993 and ends December 31, 2001.

(37) "Compliance Period" means a three-year calendar year period within a compliance cycle. Each compliance cycle has three three-year compliance periods. Within the first compliance cycle, the first compliance period runs from January 1, 1993 to December 31, 1995; the second from January 1, 1996 to December 31, 1998; and the third from January 1, 1999 to December 31, 2001.

(38) "Comprehensive performance evaluation (CPE)" means a thorough review and analysis of a treatment plant's performance-based capabilities and associated administrative, operation and maintenance practices. It is conducted to identify factors that may be adversely impacting a plant's capability to achieve compliance and emphasizes approaches that can be implemented without significant capital improvements. The CPE must consist of at least the following components: Assessment of plant performance; evaluations of major unit processes; identification and prioritization of performance limiting factors; assessment of the applicability of comprehensive technical assistance; and preparation of a CPE report.

(39) "Conceptual Model" means a three-dimensional representation of the groundwater system, including the location and extent of the hydrogeologic units, areas of recharge and discharge, hydrogeologic boundaries and hydraulic gradient.

(40) "Confined Well" means a well completed in a confined aquifer. More specifically, it is a well which produces water from a formation that is overlain by an impermeable material of extensive area. This well shall be constructed according to OAR chapter 690, division 200 "Well Construction and Maintenance" standards.

(41) "Confluent Growth" means a continuous bacterial growth covering the entire filtration area of a membrane filter, or a portion thereof, in which bacterial colonies are not discrete.

(42) "Constructed Conveyance" means any human-made conduit such as ditches, culverts, waterways, flumes, mine drains, canals or any human-altered natural water bodies or waterways as determined by the Authority.

(43) "Contaminant" means any physical, chemical, biological, or radiological substance or matter in water that creates a health hazard.

(44) "Contingency Plan" means a document setting out an organized, planned and coordinated course of action to be followed in the event of a loss of capacity to supply water to the distribution system or in case of a fire, explosion or release of hazardous waste which could threaten human health or the environment.

(45) “Continuing Education Unit (CEU)” means a nationally recognized unit of measurement for assigning credits for education or training that provides the participant with advanced or post high school learning. One CEU is awarded for every 10 classroom hours of lecture or the equivalent of participation in an organized education experience, conducted under responsible sponsorship, capable direction and qualified instruction as determined by the Authority or its designee.

(46) “Conventional Filtration Treatment Plant” means a water treatment plant using conventional or direct filtration to treat surface water or groundwater under the direct influence of surface water.

(47) "Corrosion Inhibitor" means a substance capable of reducing the corrosivity of water toward metal plumbing materials, especially lead and copper, by forming a protective film on the interior surface of those materials.

(48) "Cross Connection" means any actual or potential unprotected connection or structural arrangement between the public or user's potable water system and any other source or system through which it is possible to introduce into any part of the potable system any used water, industrial fluid, gas, or substances other than the intended potable water with which the system is supplied. Bypass arrangements, jumper connections, removable sections, swivel, or change-over devices, and other temporary or permanent devices through which, or because of which, backflow can occur are considered to be cross connections.

(49) "CT" means the product of the residual disinfectant concentration "C" (measured in mg/l) and disinfectant contact time(s), "T" (measured in minutes).

(50) "Degree of Hazard" means either pollution (non-health hazard) or contamination (health hazard) and is determined by an evaluation of hazardous conditions within a system.

(51) "Delineation" means the determination of the extent, orientation and boundaries of a wellhead protection area using factors such as geology, aquifer characteristics, well pumping rates and time of travel.

(52) "Demonstration Study" means a series of tests performed to prove an overall effective removal and/or inactivation rate of a pathogenic organism through a treatment or disinfection process.

(53) “Direct Responsible Charge (DRC)” means an individual designated by the owner or authorized agent to make decisions regarding the daily operational activities of a public water system, water treatment facility and/or distribution system, that will directly impact the quality or quantity of drinking water.

(54) "Discharge" means the volume rate of loss of groundwater from the aquifer through wells, springs or to surface water.

(55) "Disinfectant Contact Time" means the time in minutes that it takes for water to move from the point of disinfectant application or the previous point of disinfection residual measurement to a point before or at the point where residual disinfectant concentration is measured.

(56) “Disinfectant Residual Maintenance” means a process where public water systems add chlorine (or other chemical oxidant) for the purpose of maintaining a disinfectant residual in the distribution system, when the source(s) is not at risk of microbial contamination.

(57) "Disinfection" means a process which inactivates pathogenic organisms in water by chemical oxidants or equivalent agents.

(58) "Disinfection profile" means a summary of Giardia lamblia inactivation through the treatment plant.

(59) "Distribution System" means the network of pipes and other facilities, which are used to distribute water from the source, treatment, transmission, or storage facilities to the water user.

(60) "Domestic" means provided for human consumption.

(61) "Domestic or other non-distribution system plumbing problem" means a coliform contamination problem in a public water system with more than one service connection that is limited to the specific service connection from which the coliform-positive sample was taken.

(62) "Dose Equivalent" means the product of the absorbed dose from ionizing radiation and such factors as account for differences in biological effectiveness due to the type of radiation and its distribution in the body as specified by the International Commission on Radiological Units and Measurements (ICRU).

(63) "Double Check-Detector Backflow Prevention Assembly (DCDA)" means a specially designed assembly composed of a line size approved double check valve assembly assembled with a bypass containing a specific water meter and an approved double check valve assembly. The meter shall register accurately for only very low rates of flow up to three gallons per minute and shall show a registration for all rates of flow. This assembly is designed to protect against a non-health hazard.

(64) "Double Check Valve Backflow Prevention Assembly (DC)" means an assembly of two independently acting approved check valves, including tightly closing resilient seated shutoff valves attached at each end of the assembly and fitted with properly located resilient seated test cocks. This assembly is designed to protect against a non-health hazard.

(65) "Drawdown" means the difference, measured vertically, between the static water level in the well and the water level during pumping.

(66) "Drinking Water Protection" means implementing strategies within a drinking water protection area to minimize the potential impact of contaminant sources on the quality of water being used as a drinking water source by a Public Water System.

(67) "Drinking Water Protection Area (DWPA)" means the source area supplying drinking water to a Public Water System. For a surface water-supplied drinking water source the DWPA is all or a specifically determined part of a lake's, reservoir's or stream's watershed that has been certified by the Department of Environmental Quality. For a groundwater-supplied drinking water source the DWPA is the area on the surface that directly overlies that part of the aquifer that supplies groundwater to a well, well field or spring that has been certified by the Authority.

(68) "Drinking Water Protection Plan" means a plan, certified by the Department of Environmental Quality according to OAR 340-040-0160 to 340-040-0180, which identifies the actions to be taken at the local level to protect a specifically defined and certified drinking water protection area. The plan is developed by the local Responsible Management Authority and/or team and includes a written description of each element, public participation efforts, and an implementation schedule.

(69) “Dual sample set” means a set of two samples collected at the same time and same location, with one sample analyzed for TTHM and the other for HAA5. Dual sample sets are collected for the purposes of conducting an Initial Distribution System Evaluation (IDSE) as prescribed in 333-061-0036(4)(b) of these rules, and for determining compliance with the maximum contaminant levels for TTHM and HAA5 listed in OAR 333-061-0030(2)(b).

(70) "Effective Corrosion Inhibitor Residual" means a concentration sufficient to form a passivating film on the interior walls of a pipe.

(71) "Effective Porosity" means the ratio of the volume of interconnected voids (openings) in a geological formation to the overall volume of the material.

(72) "Element" means one of seven objectives considered by the U.S. EPA as the minimum required components in any state wellhead protection program: specification of duties, delineation of the wellhead protection area, inventory of potential contaminant sources, specification of management approaches, development of contingency plans, addressing new (future) wells, and ensuring public participation.

(73) "Emergency" means a condition resulting from an unusual calamity such as a flood, storm, earthquake, drought, civil disorder, volcanic eruption, an accidental spill of hazardous material, or other occurrence which disrupts water service at a public water system or endangers the quality of water produced by a public water system.

(74) "Emergency Response Plan" means a written document establishing contacts, operating procedures, and actions taken for a public water system to minimize the impact or potential impact of a natural disaster, accident, or intentional act which disrupts or damages, or potentially disrupts or potentially damages the public water system or drinking water supply, and returns the public water system to normal operating condition.

(75) "Enhanced coagulation" means the addition of sufficient coagulant for improved removal of disinfection byproduct precursors by conventional filtration treatment.

(76) "Enhanced softening" means the improved removal of disinfection byproduct precursors by precipitative softening.

(77) "EPA" means the United States Environmental Protection Agency.

(78) "Filter profile" means a graphical representation of individual filter performance, based on continuous turbidity measurements or total particle counts versus time for an entire filter run, from start-up to backwash inclusively, that includes an assessment of filter performance while another filter is being backwashed.

(79) "Filtration" means a process for removing particulate matter from water through porous media.

(a) "Conventional Filtration Treatment" means a series of processes including coagulation (requiring the use of a primary coagulant and rapid mix), flocculation, sedimentation, and filtration resulting in substantial particulate removal.

(b) "Direct Filtration Treatment" means a series of processes including coagulation (requiring the use of a primary coagulant and rapid mix) and filtration but excluding sedimentation resulting in substantial particulate removal.

(c) "Slow Sand Filtration" means a treatment process involving passage of raw water through a bed of sand at low velocity (generally less than 235 gallons per square foot per day) resulting in substantial particulate removal by physical and biological mechanisms.

(d) "Diatomaceous Earth Filtration" means a process resulting in substantial particulate removal in which:

(A) A precoat cake of diatomaceous earth filter media is deposited on a support membrane (septum); and

(B) While the water is filtered by passing through the cake on the septum, additional filter media, known as body feed, is continuously added to the feed water, in order to maintain the permeability of the filter cake.

(80) “Filtration Endorsement” means a special provision added to a Water Treatment Operator's certification that includes experience in and knowledge of the operational decision making at a Conventional or Direct Filtration Treatment Plant.

(81) “Finished water” means water that is introduced into the distribution system of a public water system and intended for distribution and consumption without further treatment, except as necessary to maintain water quality in the distribution system such as booster disinfection or the addition of corrosion control chemicals.

(82) "First Customer" means the initial service connection or tap on a public water supply after any treatment processes.

(83) "First Draw Sample" means a one-liter sample of tap water that has been standing in plumbing pipes at least 6 hours and is collected without flushing the tap.

(84) "Flocculation" means a process to enhance agglomeration or collection of smaller floc particles into larger, more easily settleable particles through gentle stirring by hydraulic or mechanical means.

(85) “Flowing stream” means a course of running water flowing in a definite channel.

(86) "Future Groundwater Sources" means wells and/or springs that may be required by the public water system in the future to meet the needs of the system.

(87) "GAC 10" means granular activated carbon filter beds with an empty-bed contact time of 10 minutes based on average daily flow and a carbon reactivation frequency of every 180 days, except that the reactivation frequency for GAC10 used as a best available technology for compliance with OAR 333-061-0030(2)(b) shall be 120 days.

(88) “GAC 20” means granular activated carbon filter beds with an empty-bed contact time of 20 minutes based on average daily flow and a carbon reactivation frequency of every 240 days.

(89) "Gross Alpha Particle Activity" means the total radioactivity due to alpha particle emission as inferred from measurements on a dry sample.

(90) "Gross Beta Particle Activity" means the total radioactivity due to beta particle emission as inferred from measurements on a dry sample.

(91) "Groundwater" means any water, except capillary moisture, beneath the land surface or beneath the bed of any stream, lake, reservoir or other body of surface water within the boundaries of this state, whatever may be the geologic formation or structure in which such water stands, flows, percolates or otherwise moves.

(92) “Groundwater System” means any public water system that uses groundwater, including purchasing water systems that receive finished groundwater, but excluding public water systems that combine all of their groundwater with surface water or groundwater under the direct influence of surface water prior to treatment.

(93) "Groundwater under the direct influence of surface water (GWUDI)" means any water beneath the surface of the ground with significant occurrence of insects or other macro-organisms, algae or large-diameter pathogens such as Giardia lamblia or Cryptosporidium, or significant and relatively rapid shifts in water characteristics such as turbidity, temperature, conductivity, or pH which closely correlate to climatological or surface water conditions.

(94) "Haloacetic acids (five) (HAA5)" mean the sum of the concentrations in milligrams per liter of the haloacetic acid compounds (monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid and dibromoacetic acid), rounded to two significant figures after addition.

(95) "Hauled Water" means water for human consumption transported from a Public Water System in a manner approved by the Authority.

(96) "Health Hazard (Contamination)" means an impairment of the quality of the water that could create an actual hazard to the public health through poisoning or through the spread of disease by sewage, industrial fluids, waste, or other substances.

(97) "Human Consumption" means water used for drinking, personal hygiene bathing, showering, cooking, dishwashing, and maintaining oral hygiene.

(98) "Hydraulic Conductivity" means the capacity of the medium, e.g., soil, aquifer, or any hydrogeological unit of interest, to transmit water.

(99) "Hydraulic Connection" refers to a well, spring or other groundwater collection system in which it has been determined that part of the water supplied by the collection system is derived, either naturally or induced, from a surface water source.

(100) "Hydraulic Gradient" means the slope of the water table or potentiometric surface, calculated by dividing the change in hydraulic head between two points by the horizontal distance between the points in the direction of groundwater flow.

(101) "Hydraulic Head" means the energy possessed by the water mass at a given point, related to the height above the datum plane that water resides in a well drilled to that point. In a groundwater system, the hydraulic head is composed of elevation head and pressure head.

(102) "Hydrogeologic Boundary" means physical features that bound and control direction of groundwater flow in a groundwater system. Boundaries may be in the form of a constant head, e.g. streams, or represent barriers to flow, e.g. groundwater divides and impermeable geologic barriers.

(103) "Hydrogeologic Mapping" means characterizing hydrogeologic features (e.g. hydrogeologic units, hydrogeologic boundaries, etc.) within an area and determining their location, areal extent and relationship to one another.

(104) "Hydrogeologic Unit" means a geologic formation, group of formations, or part of a formation that has consistent and definable hydraulic properties.

(105) "Impermeable Material" means a material that limits the passage of water.

(106) "Impounding Reservoir" means an uncovered body of water formed behind a dam across a river or stream, and in which water is stored.

(107) "Infiltration Gallery" means a system of perforated pipes laid along the banks or under the bed of a stream or lake installed for the purpose of collecting water from the formation beneath the stream or lake.

(108) "Initial Compliance Period" means the 1993-95 three-year compliance period for systems with 150 or more service connections and the 1996-98 three-year compliance period for systems having fewer than 150 service connections for the contaminants prescribed in OAR 333-061-0036(2)(a), 333-061-0036(3)(a) and (3)(b).

(109) "Interfering Wells" means wells that, because of their proximity and pumping characteristics, and as a result of the aquifer's hydraulic properties, produce drawdown cones that overlap during simultaneous pumping. The result is a lowering of the pumping level in each well below what it would be if that well were pumping by itself.

(110) "Inventory of Potential Contaminant Sources" means the reconnaissance level location of land use activities within the Drinking Water Protection Area that as a category have been associated with groundwater or surface water contamination in Oregon and elsewhere in the United States.

(111) “Lake/reservoir” means a natural or man-made basin or hollow on the Earth’s surface in which water collects or is stored that may or may not have a current or single direction of flow.

(112) "Lead Free" when used with respect to solders and flux shall mean solders and flux containing not more than 0.2 percent lead, and when used with respect to pipes and fittings shall mean pipes and fittings containing not more than 8.0 percent lead. When used with respect to plumbing fittings and fixtures intended for dispensing water for human consumption shall mean in compliance with standards established in accordance with 42 U.S.C. 300g-6(e) and ANSI/NSF standard 61, section 9.

(113) "Lead Service Line" means a service line made of lead, which connects the water main to the building inlet and any pigtail, gooseneck or other fitting, which is connected to such lead line.

(114) "Legionella" means a genus of bacteria, some species of which have caused a type of pneumonia called Legionnaires Disease.

(115) "Local Administrative Authority" means the individual official, board, department or agency established and authorized by a state, county or city to administer and enforce the provisions of the Oregon State Plumbing Specialty Code adopted under OAR 918-750-0110.

(116) “Locational running annual average (LRAA)” means the arithmetic average of analytical results for samples taken at a specific monitoring location during the previous four calendar quarters.

(117) "Major Additions or Modifications" means changes of considerable extent or complexity including, but not limited to, projects involving water sources, treatment facilities, facilities for continuous disinfection, finished water storage, pumping facilities, transmission mains, and distribution mains, except main replacements of the same length and diameter.

(118) "Man-made Beta Particle and Photon Emitters" means all radionuclides emitting beta particles and/or photons listed in Maximum Permissible Body Burdens and Maximum Permissible Concentration of Radionuclides in Air or Water for Occupational Exposure, NBS Handbook 69, except the daughter products of Thorium-232, Uranium-235 and Uranium-238.

(119) "Master Plan" means an overall plan, which shows the projected development of a distribution system and alternatives for source development.

(120) "Maximum Contaminant Level (MCL)" means the maximum allowable level of a contaminant in water delivered to the user's of a public water system, except in the case of turbidity where the maximum allowable level is measured at the point of entry to the distribution system.

(121) "Maximum Residual Disinfectant Level (MRDL)" means a level of a disinfectant added for water treatment that may not be exceeded at the consumer's tap without an unacceptable possibility of adverse health effects.

(122) “Membrane filtration” means a pressure or vacuum driven separation process in which particulate matter larger than one micrometer is rejected by an engineered barrier, primarily through a size-exclusion mechanism, and which has a measurable removal efficiency of a target organism that can be verified through the application of a direct integrity test. This definition includes the common membrane technologies of microfiltration, ultrafiltration, nanofiltration, and reverse osmosis.

(123) "Multi-purpose Piping System" means a piping system within residential dwellings intended to serve both domestic and fire protection needs. This type of system is considered part of a potable water system.

(124) "New Groundwater Sources" means additional or modified wells and/or springs owned by the Public Water System.

(125) "Non-Health Hazard (Pollution)" means an impairment of the quality of the water to a degree that does not create a hazard to the public health, but does adversely affect the aesthetic qualities of such water for potable use.

(126) "Non-Transient Non-Community Water System (NTNC)" means a public water system that is not a Community Water System and that regularly serves at least 25 of the same persons over 6 months per year.

(127) "Open Interval" means in a cased well, the sum of the length(s) of the screened or perforated zone(s) and in an uncased (open-hole) well, the sum of the thickness(es) of the water-bearing zones or, if undeterminable, 10 percent of the length of the open hole.

(128) “Operating Experience” means the routine performance of duties, tasks, and responsibilities at a drinking water system or in a related field as allowed under OAR 333-061-0245(6)(b).

(129) “Operational Decision Making” means having responsibility for making decisions among the alternatives in the performance of the water treatment plant or the water distribution system regarding water quality or quantity which affect public health.

(130) “Operator,” for the purposes of OAR 333-061-0210 through 0290, means an individual with responsibilities that directly impact the quality of drinking water including individuals making process control or system integrity decisions about water quality or quantity that affect public health. This term does not include officials, managers, engineers, directors of public works, or equivalent whose duties do not include the actual “hands-on” operation or supervision on-site of water system facilities or operators.

(131) "Optimal Corrosion Control Treatment" means the corrosion control treatment that minimizes the lead and copper concentrations at users' taps while insuring that the treatment does not cause the water system to violate any national primary drinking water regulations.

(132) "Pathogenic" means a specific agent (bacterium, virus or parasite) causing or capable of causing disease.

(133) "Peak Daily Demand" means the maximum rate of water use, expressed in gallons per day, over the 24-hour period of heaviest consumption.

(134) "Permit" means official permission granted by the Authority for a public water system which exceeds maximum contaminant levels to delay, because of economic or other compelling factors, the installation of water treatment facilities which are necessary to produce water which does not exceed maximum contaminant levels.

(135) "Person" means any individual, corporation, association, firm, partnership, municipal, state or federal agency, or joint stock company and includes any receiver, special master, trustee, assignee, or other similar representative thereof.

(136) "Picocurie (pCi)" means that quantity of radioactive material producing 2.22 nuclear transformations per minute.

(137) "Pilot Study" means the construction and operation of a scaled down treatment system during a given period of time to determine the feasibility a full-scale treatment facility.

(138) “Plant intake” means the works or structures at the head of a conduit through which water is diverted from a source, such as a river or lake, into a treatment plant.

(139) "Plug Flow" means movement of water in a pipe such that particles pass through the pipe and are discharged in the same sequence in which they entered.

(140) "Point of Delivery (POD)" means the point of connection between a public water system and the user's water system. Beyond the point of delivery, the Oregon Plumbing Specialty Code applies. See "Service Connection."

(141) "Point of Disinfectant Application" is the point where the disinfectant is applied and water downstream of that point is not subject to recontamination by surface water runoff.

(142) "Point-of-Entry Treatment Device" is a treatment device applied to the drinking water entering a house or building for the purpose of reducing contaminants in the drinking water distributed throughout the house or building.

(143) "Point-of-Use Treatment Device" is a treatment device applied to a single tap used for the purpose of reducing contaminants in drinking water at that one tap.

(144) "Pollutant" means a substance that creates an impairment of the quality of the water to a degree which does not create a hazard to the public health, but which does adversely affect the aesthetic qualities of the water.

(145) "Porous Media Assumption" means the assumption that groundwater moves in the aquifer as if the aquifer were granular in character, i.e. moves directly down-gradient, and the velocity of the groundwater can be described by Darcy's Law.

(146) “Post High School Education” means that education acquired through programs such as short schools, bona fide correspondence courses, trade schools, colleges, universities, formalized workshops or seminars that are acceptable to the Authority and for which college or continuing education credit is issued by the training sponsor.

(147) "Potable Water" See Safe Drinking Water.

(148) "Potential Contaminant Source Inventory" means the determination of the location within the wellhead protection area of activities known to use or produce materials that can contaminate groundwater.

(149) "Potential Cross Connection" means a cross connection that would most likely occur, but may not be taking place at the time of an inspection.

(150) "Potentiometric Surface" means a surface that denotes the variation of hydraulic head in the given aquifer across an area.

(151) "Premise" means real estate and the structures on it.

(152) "Premise Isolation" means the practice of protecting the public water supply from contamination or pollution by installing backflow prevention assemblies at, or near, the point of delivery where the water supply enters the premise. Premise isolation does not guarantee protection to persons on the premise.

(153) “Presedimentation” means a preliminary treatment process used to remove gravel, sand and other particulate material from the source water through settling before the water enters the primary clarification and filtration processes in a treatment plant.

(154) "Pressure Vacuum Breaker Backsiphonage Prevention Assembly (PVB)" means an assembly consisting of an independently operating, internally loaded check valve and an independently operating loaded air inlet valve located on the discharge side of the check valve. This assembly is to be equipped with properly located resilient seated test cocks and tightly closing resilient seated shutoff valves attached at each end of the assembly. This assembly is designed to protect against a non-health hazard or a health hazard under backsiphonage conditions only.

(155) "Provisional Delineation" means approximating the wellhead protection area for a well by using the wellhead protection area from another well in the same hydrogeologic setting or by using generalized values for the aquifer characteristics to generate an approximate wellhead protection area for the well. Used only for the purpose of evaluating potential siting of new or future groundwater sources. Not an acceptable way to formally delineate a wellhead protection area.

(156) "Public Health Hazard" means a condition, device or practice which is conducive to the introduction of waterborne disease organisms, or harmful chemical, physical, or radioactive substances into a public water system, and which presents an unreasonable risk to health.

(157) "Public Water System" means a system for the provision to the public of piped water for human consumption, if such system has more than three service connections, or supplies water to a public or commercial establishment that operates a total of at least 60 days per year, and that is used by 10 or more individuals per day. Public water system also means a system for the provision to the public of water through constructed conveyances other than pipes to at least 15 service connections or regularly serves at least 25 individuals daily at least 60 days of the year. A public water system is either a "Community Water System," a "Transient Non-Community Water System," a "Non-Transient Non-Community Water System" or a "State Regulated Water System."

(158) "Purchasing Water System" means a public water system which obtains its water in whole or in part from one or more public water systems. Delivery may be through a direct connection or through the distribution system of one or more purchasing water systems.

(159) "Recharge" means the process by which water is added to a zone of saturation, usually by downward infiltration from the surface.

(160) "Recharge Area" means a land area in which water percolates to the zone of saturation through infiltration from the surface.

(161) "Recovery" means the rise in water level in a well from the pumping level towards the original static water level after pumping has been discontinued.

(162) "Reduced Pressure Principle Backflow Prevention Assembly (RP)" means an assembly containing two independently acting approved check valves, together with a hydraulically operating, mechanically independent pressure differential relief valve located between the check valves and at the same time below the first check valve. The unit shall include properly located resilient seated test cocks and tightly closing resilient seated shutoff valves at each end of the assembly. This assembly is designed to protect against a non-health hazard or a health hazard.

(163) "Reduced Pressure Principle-Detector Backflow Prevention Assembly (RPDA)" means a specifically designed assembly composed of a line size approved reduced pressure principle backflow prevention assembly with a bypass containing a specific water meter and an approved reduced pressure principle backflow prevention assembly. The meter shall register accurately for only very low rates of flow up to three gallons per minute and shall show a registration for all rates of flow. This assembly is designed to protect against a non-health hazard or a health hazard.

(164) "Rem" means the unit of dose equivalent from ionizing radiation to the total body or any internal organ or organ system. A "millirem (mrem)" is 1/1000 of a rem.

(165) "Repeat Compliance Period" means any subsequent compliance period after the initial compliance period.

(166) "Residual disinfectant concentration" means the concentration of disinfectant measured in mg/l in a representative sample of water.

(167) "Responsible Management Authority" means the Public Water System whose water supply is being protected and any government entity having management, rule or ordinance-making authority to implement wellhead protection management strategies within the wellhead protection area. The Responsible Management Authority is responsible for implementation of the Wellhead Protection Plan and includes cities, counties, special districts, Indian tribes, state/federal entities as well as public water systems.

(168) "Safe Drinking Water" means water which has sufficiently low concentrations of microbiological, inorganic chemical, organic chemical, radiological or physical substances so that individuals drinking such water at normal levels of consumption, will not be exposed to disease organisms or other substances which may produce harmful physiological effects.

(169) "Sanitary Survey (Water System Survey)" means an on-site review of the water source(s), facilities, equipment, operation, maintenance and monitoring compliance of a public water system to evaluate the adequacy of the water system, its sources and operations in the distribution of safe drinking water. The sanitary survey also identifies sources of contamination by using the results of source water assessments where available.

(170) "Secondary Contaminant" means those contaminants, which, at the levels generally found in drinking water, do not present an unreasonable risk to health, but do:

(a) Have adverse effects on the taste, odor and color of water;

(b) Produce undesirable staining of plumbing fixtures; or

(c) Interfere with treatment processes applied by water suppliers.

(171) "Secondary Maximum Contaminant Level (SMCL)" means the level of a secondary contaminant which when exceeded may adversely affect the aesthetic quality of the drinking water which thereby may deter public acceptance of drinking water provided by public water systems or may interfere with water treatment methods.

(172) "Sedimentation" means a process for removal of solids before filtration by gravity or separation.

(173) "Seller's Designee" means the person assigned by the seller to complete the necessary paperwork and submit the lab results to the Authority and can be the seller’s attorney, real estate agent or broker, the person conducting the tests or a private party.

(174) "Sensitivity" means the intrinsic characteristics of a drinking water source such as depth to the aquifer for groundwater or highly erodible soils in a watershed that increase the potential for contamination to take place if a contaminant source is present.

(175) "Service Connection" means the piping connection by means of which water is conveyed from a distribution main of a public water system to a user's premise. For a community water system, the portion of the service connection that conveys water from the distribution main to the user's property line, or to the service meter, where provided, is under the jurisdiction of the water supplier.

(176) “Significant Deficiency” means a defect in design, operation, or maintenance, or a malfunction of the source(s), treatment, storage, or distribution system that has been determined to cause or have the potential for causing the introduction of contamination into the water delivered to consumers.

(177) "Single Connection System" means a public water system serving only one installation, such as a restaurant, campground or place of employment.

(178) "Single Family Structure" means a building constructed as a single-family residence that is currently used as either a residence or a place of business.

(179) “Small Water System,” for the purposes of OAR 333-061-0210 through 0295, means a community or non-transient non-community water system serving fewer than 150 connections and either uses groundwater as its only source or purchases its water from another public water system without adding any additional treatment.

(180) "Source Water Assessment" means the information compiled by the Authority and the Department of Environmental Quality (DEQ), consisting of the delineation, inventory and susceptibility analyses of the drinking water source, which enable public water systems to develop and implement drinking water protection plans.

(181) "Specific Ultraviolet Absorption (SUVA) at 254 nanometers" means an indicator of the humic content of water as a calculated parameter obtained by dividing a sample's ultraviolet absorption at a wavelength of 254 nanometers (UV254) by its concentration of dissolved organic carbon (DOC) (in milligrams per liter).

(182) "Spill Resistant Pressure Vacuum Breaker Backsiphonage Prevention Assembly (SVB)" means an assembly containing an independently operating, internally loaded check valve and independently operating loaded air inlet valve located on the discharge side of the check valve. The assembly is to be equipped with a properly located resilient seated test cock, a properly located bleed/vent valve, and tightly closing resilient seated shutoff valves attached at each end of the assembly. This assembly is designed to protect against a non-health hazard or a health hazard under a backsiphonage condition only.

(183) "Spring" means a naturally occurring discharge of flowing water at the ground surface, or into surface water where the flow of water is the result of gravity or artesian pressure. Springs can be derived from groundwater or they can be surface water influenced.

(184) "Stand-alone Fire Suppression System" means a piping system within a premise intended to only serve as a fire protection system separated from the potable water system.

(185) "State Regulated Water System" means a public water system, which serves 4 to 14 service connections or serves 10 to 24 people. Monitoring requirements for these systems are the same as those for Transient Non-Community water systems.

(186) "Static Water Level" means the vertical distance from ground surface to the water level in the well when the well is at rest, i.e., the well has not been pumped recently and the water level is stable. This is the natural level of water in the well.

(187) "Submeter" means a water meter by which a property owner (or association of property owners) meters individual water use after the water passes through a master meter. For the purposes of OAR 333-061-0010, submetering does not constitute applying a direct charge for water or directly selling water to a person.

(188) "Surface Water" means all water, which is open to the atmosphere and subject to surface runoff.

(189) "Susceptibility" means the potential, as a result of the combination of land use activities and source water sensitivity that contamination of the drinking water source may occur.

(190) "Team" means the local Wellhead Protection team, which includes representatives from the Responsible Management Authorities and various interests and stakeholders potentially affected by the Wellhead Protection Plan.

(191) "Thermal Expansion" means the pressure increase due to a rise in water temperature that occurs in water piping systems when such systems become "closed" by the installation of a backflow prevention assembly or other means, and will not allow for expansion beyond that point of installation.

(192) "These Rules" means the Oregon Administrative Rules encompassed by OAR 333-061-0005 through 333-061-0335.

(193) "Time-of-Travel (TOT)" means the amount of time it takes groundwater to flow to a given well. The criterion that effectively determines the radius in the calculated fixed radius method and the up-gradient distance to be used for the analytical and numerical models during delineation of the wellhead protection area.

(194) "Too Numerous To Count (TNTC)" means that the total number of bacterial colonies exceeds 200 on a 47 mm diameter membrane filter used for coliform bacteria detection.

(195) "Total Organic Carbon (TOC)" means total organic carbon in milligrams per liter measured using heat, oxygen, ultraviolet irradiation, chemical oxidants, or combinations of these oxidants that convert organic carbon to carbon dioxide, rounded to two significant figures.

(196) “Total Trihalomethanes (TTHM)” means the sum of the concentrations in milligrams per liter of the trihalomethane compounds bromodichloromethane, dibromochloromethane, tribromomethane (bromoform) and trichloromethane (chloroform), rounded to two significant figures after addition.

(197) "Transient Non-Community Water System (TNC)" means a public water system that serves a transient population of 25 or more persons.

(198) "Turbidity" means a measure of the cloudiness of water caused by suspended particles. The units of measure for turbidity are nephelometric turbidity units (NTU).

(199) “Two-stage lime softening” means a process in which a chemical addition and hardness precipitation occur in each of two distinct unit clarification processes in series prior to filtration.

(200) "Unconfined Well" means a well completed in an unconfined aquifer. More specifically, a well which produces water from a formation that is not overlaying by impermeable material. This well shall be constructed according to OAR chapter 690, division 200 "Well Construction and Maintenance" standards.

(201) “Uncovered finished water storage facility” means a tank, reservoir, or other facility used to store water that will undergo no further treatment to reduce microbial pathogens except residual disinfection and is directly open to the atmosphere.

(202) "University of Southern California, Foundation for Cross-Connection Control and Hydraulic Research (USC FCCCHR)" is an agency that conducts laboratory and field tests to evaluate and grant "Certificates of Approval" to backflow prevention assemblies meeting approved standards.

(203) "Vadose Zone" means the zone between the ground surface and the water table where the available open spaces between soil and sediment particles, in rock fractures, etc., are most filled with air.

(204) "Variance" means official permission granted by the Authority for public water systems to exceed maximum contaminant levels because the quality of the raw water is such that the best available treatment techniques are not capable of treating the water so that it complies with maximum contaminant levels, and there is no unreasonable risk to health.

(205) "Vault" means an approved enclosure above or below ground to house a backflow prevention assembly that complies with the local administrative authority having jurisdiction.

(206) "Virus" means a virus of fecal origin, which is infectious to humans by waterborne transmission.

(207) "Waiver" means official permission from the Authority for a public water system to deviate from the construction standards set forth in these rules.

(208) "Water-bearing Zone" means that part or parts of the aquifer encountered during drilling that yield(s) water to a well.

(209) "Waterborne disease outbreak" means the significant occurrence of acute infectious illness, epidemiologically associated with the ingestion of water from a public water system which is deficient in treatment, as determined by the Authority.

(210) "Water Source" means any lake, stream, spring, groundwater supply, impoundment or other source of water from which water is obtained for a public water system. In some cases, a public water system can be the source of supply for one or more other public water systems.

(211) "Water Supplier" means a person, group of persons, municipality, district, corporation or other entity, which owns or operates a public potable water system.

(212) "Water System" means a system for the provision of piped water for human consumption.

(213) "Water System Operations Manual" means a written document describing the actions and procedures necessary to operate and maintain the entire water system.

(214) "Water Table" means the upper surface of an unconfined aquifer, the surface of which is at atmospheric pressure and fluctuates seasonally. It is defined by the levels at which water stands in wells that penetrate the aquifer.

(215) “Water Treatment” means a process of altering water quality by physical or chemical means and may include domestic, industrial or commercial applications.

(216) "Well" means an artificial opening or artificially altered natural opening, however made, by which ground water is sought or through which ground water flows under natural pressure or is artificially withdrawn or injected, provided that this definition shall not include a natural spring, or wells drilled for the purpose of exploration or production of oil or gas.

(217) "Wellfield" means two or more drinking water wells, belonging to the same water system that are within 2,500 feet, or as determined by the Authority, and produce from the same and no other aquifer.

(218) "Wellhead Protection." See Drinking Water Protection.

(219) "Wellhead Protection Area (WHPA)." See Drinking Water Protection Area.

(220) "Wellhead Protection Plan." See Drinking Water Protection Plan.

(221) “Wholesale system” means a public water system that treats source water as necessary to produce finished water and then delivers some or all of that finished water to another public water system. Delivery may be through a direct connection or through the distribution system of one or more purchasing water systems.

[Publications: Publications referenced are available from the agency.]

Stat. Auth.: ORS 448.131
Stats. Implemented: ORS 431.110, 431.150, 448.131, 448.150, 448.273, 448.279

Hist.: HD 106, f. & ef. 2-6-76; HD 4-1980, f. & ef. 3-21-80; HD 10-1981, f. & ef. 6-30-81; HD 17-1981(Temp), f. & ef. 8-28-81; HD 4-1982, f. & ef. 2-26-82; Renumbered from 333-042-0205, HD 2-1983, f. & ef. 2-23-83; HD 21-1983, f. 10-20-83, ef. 11-1-83; HD 11-1985, f. & ef. 7-2-85; HD 30-1985, f. & ef. 12-4-85; HD 3-1987, f. & ef. 2-17-87; HD 3-1988(Temp), f. & cert. ef. 2-12-88; HD 17-1988, f. & cert. ef. 7-27-88; HD 9-1989, f. & cert. ef. 11-13-89; HD 26-1990, f. 12-26-90, cert. ef. 12-29-90; HD 7-1992, f. & cert. ef. 6-9-92; HD 12-1992, f. & cert. ef. 12-7-92; HD 3-1994, f. & cert. ef. 1-14-94; HD 1-1996, f. 1-2-96, cert. ef. 1-5-96; HD 14-1997, f. & cert. ef. 10-31-97; OHD 4-1999, f. 7-14-99, cert. ef. 7-15-99; OHD 3-2000, f. 3-8-00, cert. ef. 3-15-00; OHD 7-2000, f. 7-11-00, cert. ef. 7-15-00; OHD 23-2001, f. & cert. ef. 10-31-01; OHD 17-2002, f. & cert. ef. 10-25-02; PH 16-2004(Temp), f. & cert. ef. 4-9-04 thru 10-5-04; PH 20-2004, f. & cert. ef. 6-18-04; PH 33-2004, f. & cert. ef. 10-21-04; PH 34-2004, f. & cert. ef. 11-2-04; PH 2-2006, f. & cert. ef. 1-31-06; PH 4-2009, f. & cert. ef. 5-18-09; PH 7-2010, f. & cert. ef. 4-19-10; PH 5-2011(Temp), f. & cert. ef. 7-1-11 thru 12-27-11; PH 11-2011, f. & cert. ef. 10-27-11; PH 13-2012, f. & cert. ef. 9-10-12

333-061-0025

Responsibilities of Water Suppliers

Water suppliers are responsible for taking all reasonable actions to assure that the water delivered to water users does not exceed maximum contaminant levels, to assure that water system facilities are free of public health hazards, and to assure that water system operation and maintenance are performed as required by these rules. Such actions include, but are not limited to:

(1) Routinely collecting and submitting water samples for laboratory analyses at the frequencies prescribed by OAR 333-061-0036;

(2) Taking immediate corrective action when the results of analyses or measurements indicate that maximum contaminant levels have been exceeded and report the results of these analyses as prescribed by OAR 333-061-0040;

(3) Reporting as prescribed by OAR 333-061-0040, the results of analyses or measurements which indicate that maximum contaminant levels have not been exceeded;

(4) Notifying all customers of the water system and the general public in the service area, as prescribed by OAR 333-061-0042, when the maximum contaminant levels have been exceeded;

(5) Notifying all customers served by the water system, as prescribed by OAR 333-061-0042, when reporting requirements are not being met, when public health hazards are found to exist in the system, or when the operation of the system is subject to a permit or a variance;

(6) Maintaining monitoring and operating records and making these records available for review when the system is inspected;

(7) Maintaining a pressure of at least 20 pounds per square inch (psi) at all service connections at all times;

(8) Following-up on complaints relating to water quality from users and maintaining records and reports on actions undertaken;

(9) Conducting an active program for systematically identifying and controlling cross connections;

(10) Submitting, to the Authority, plans prepared by a professional engineer registered in Oregon for review and approval before undertaking the construction of new water systems or major modifications to existing water systems, unless exempted from this requirement;

(11) Assuring that the water system is in compliance with OAR 333-061-0032 relating to water treatment;

(12) Assuring that the water system is in compliance with OAR 333-061-0205 relating to certification of water system operators; and

(13) Assuring that Transient Non-Community water systems utilizing surface water sources or groundwater sources under the influence of surface water are in compliance with OAR 333-061-0065(2)(c) relating to required special training.

Stat. Auth.: ORS 448.131

Stats. Implemented: ORS 448.123, 448.131, 448.135, 448.150, 448.278, 448.279, 448.450, 448.455 & 448.460

Hist.: HD 4-1982, f. & ef. 2-26-82; Renumbered from 333-042-0206, HD 2-1983, f. & ef. 2-23-83; HD 9-1989, f. & cert. ef. 11-13-89; HD 7-1992, f. & cert. ef. 6-9-92; OHD 17-2002, f. & cert. ef. 10-25-02; PH 16-2004(Temp), f. & cert. ef. 4-9-04 thru 10-5-04; PH 20-2004, f. & cert. ef. 6-18-04; PH 4-2009, f. & cert. ef. 5-18-09; PH 3-2013, f. & cert. ef. 1-25-13

333-061-0030

Maximum Contaminant Levels and Action Levels

(1) Maximum contaminant levels (MCLs) and Action Levels (ALs) for inorganic chemicals are applicable to all Community and Non-transient Non-community water systems and are listed in Table 1. The MCL for Fluoride is applicable only to Community Water Systems and the MCL for Nitrate is applicable to all water systems. [Table not included. See ED. NOTE.]

(a) Compliance with the maximum contaminant levels for inorganic contaminants is calculated pursuant to OAR 333-061-0036(2)(i).

(b) Violations of secondary contaminant levels for fluoride (2.0 mg/l) require a special public notice. Refer to OAR 333-061-0042(7).

(c) The lead action level is exceeded if the concentration of lead in more than 10 percent of tap water samples collected during any monitoring period conducted in accordance with OAR 333-061-0036(2)(c)(A) through (E) is greater than 0.015 mg/L (i.e., if the "90th percentile" lead level is greater than 0.015 mg/L). The copper action level is exceeded if the concentration of copper in more than 10 percent of tap water samples collected during any monitoring period conducted in accordance with OAR 333-061-0036(2)(c)(A) through (E) is greater than 1.3 mg/L (i.e., if the "90th percentile" copper level is greater than 1.3 mg/L).

(A) The 90th percentile lead and copper levels shall be computed as follows: The results of all lead or copper samples taken during a monitoring period shall be placed in ascending order from the sample with the lowest concentration to the sample with the highest concentration. Each sampling result shall be assigned a number, ascending by single integers beginning with the number 1 for the sample with the lowest contaminant level. The number assigned to the sample with the highest contaminant level shall be equal to the total number of samples taken. The number of samples taken during the monitoring period shall be multiplied by 0.9. The contaminant concentration in the numbered sample yielded by this calculation is the 90th percentile contaminant level.

(B) For water systems serving fewer than 100 people that collect five samples per monitoring period, the 90th percentile is computed by taking the average of the highest and second highest concentrations. For a water system allowed by the Authority to collect fewer than five samples the sample result with the highest concentration is considered the 90th percentile value.

(2) Maximum contaminant levels for organic chemicals:

(a) The maximum contaminant levels for synthetic organic chemicals are shown in Table 2 and apply to all Community and Non-Transient Non-Community water systems. Compliance with MCLs shall be calculated pursuant to OAR 333-061-0036(3)(a)(G). [Table not included. See ED. NOTE.]

(b) The maximum contaminant levels for disinfection byproducts are shown in Table 3 and apply to all Community and Non-Transient Non-Community water systems that add a disinfectant (oxidant) to the water supply at any point in the treatment process or deliver water in which a disinfectant has been added to the water supply. [Table not included. See ED. NOTE.]

(A) Compliance with the MCLs for TTHM and HAA5 shall be calculated as a running annual arithmetic average as prescribed by OAR 333-061-0036(4)(c) and (4)(p) until the dates specified in Table 4, at which time compliance with the MCLs shall be calculated as a locational running annual arithmetic average pursuant to OAR 333-061-0036(4)(d). [Table not included. See ED. NOTE.]

(B) Compliance with the MCL for Bromate shall be calculated as a running annual arithmetic average pursuant to OAR 333-061-0036(4)(l) and (r).

(C) Compliance with the MCL for Chlorite shall be calculated as a running annual arithmetic average pursuant to OAR 333-061-0036(4)(k) and (s).

(c) The maximum contaminant levels for volatile organic chemicals are indicated in Table 5 and apply to all Community and Non-Transient Non-Community water systems. Compliance with MCLs shall be calculated pursuant to OAR 333-061-0036(3)(b)(I) and (J). [Table not included. See ED. NOTE.]

(d) When the Authority has reason to believe that a water supply has been contaminated by a toxic organic chemical, it will determine whether a public health hazard exists and whether control measures must be carried out;

(e) The Authority may establish maximum contaminant levels for additional organic chemicals as deemed necessary when there is reason to suspect that the use of those chemicals will impair water quality to an extent that poses an unreasonable risk to the health of the water users;

(f) Persons who apply pesticides on watersheds above surface water intakes of public water systems shall comply with federal and state pesticide application requirements. (Safe Drinking Water Act (EPA), Clean Water Act (EPA), Federal Insecticide, Fungicide and Rodenticide Act (EPA), ORS 536.220 to 536.360 (Water Resources), 468B.005 (DEQ), 527.610 to 527.990 (DOF), 634.016 to 634.992 (Department of Agriculture)). Any person who has reasonable cause to believe that his or her actions have led to organic chemical contamination of a public water system shall report that fact immediately to the water supplier.

(3) Maximum contaminant levels for turbidity are applicable to all public water systems using surface water sources or groundwater sources under the direct influence of surface water in whole or in part. Compliance with MCLs shall be calculated pursuant to OAR 333-061-0036(5).

(a) Beginning January 1, 1992, the maximum contaminant levels for turbidity for systems which do not provide filtration treatment are as follows:

(A) The turbidity level cannot exceed 5 NTU in representative samples of the source water immediately prior to the first or only point of disinfectant application unless:

(i) The Authority determines that any such event was caused by circumstances that were unusual and unpredictable; and

(ii) As a result of any such event, there have not been more than two events in the past 12 months the system served water to the public, or more than five events in the past 120 months the system served water to the public, in which the turbidity level exceeded 5 NTU. An "event" is a series of consecutive days during which at least one turbidity measurement each day exceeds 5 NTU. Turbidity measurements must be collected as required by OAR 333-061-0036(5)(a)(B).

(b) Beginning June 29, 1993 or 18 months after failure to meet the requirements of OAR 333-061-0032(1) through (3) whichever is later, the maximum contaminant levels for turbidity in drinking water measured at a point representing filtered water prior to any storage are as follows:

(A) Conventional filtration treatment or direct filtration treatment.

(i) For systems using conventional filtration or direct filtration treatment the turbidity level of representative samples of a system's filtered water, measured as soon after filtration as possible and prior to any storage, must be less than or equal to 0.3 NTU in at least 95 percent of the measurements taken each month, measured as specified in OAR 333-061-0036(5).

(ii) For systems using conventional filtration or direct filtration treatment the turbidity level of representative samples of a system's filtered water, measured as soon after filtration as possible and prior to any storage, must at no time exceed 1 NTU measured as specified in OAR 333-061-0036(5).

(B) Slow sand filtration.

(i) For systems using slow sand filtration, the turbidity level of representative samples of filtered water, measured as soon after filtration as possible and prior to any storage, must be less than or equal to 1 NTU in at least 95 percent of the measurements taken each month, measured as specified in OAR 333-061-0036(5)(b), except that if the Authority determines there is no significant interference with disinfection at a higher turbidity level, the Authority may substitute this higher turbidity limit for that system.

(ii) The turbidity level of representative samples of filtered water must at no time exceed 5 NTU, measured as specified in OAR 333-061-0036(5)(b).

(C) Diatomaceous earth filtration.

(i) For systems using diatomaceous earth filtration, the turbidity level of representative samples of filtered water, measured as soon after filtration as possible and prior to any storage, must be less than or equal to 1 NTU in at least 95 percent of the measurements taken each month, measured as specified in OAR 333-061-0036(5)(b).

(ii) The turbidity level of representative samples of filtered water must at no time exceed 5 NTU, measured as specified in OAR 333-061-0036(5)(b).

(D) Other filtration technologies. Systems using filtration technologies other than those listed in paragraphs (3)(b)(A) through (C) of this rule must meet the maximum contaminant level for turbidity of 1 NTU in at least 95 percent of the measurements taken each month and at no time exceed 5 NTU, as specified in OAR 333-061-0036(5)(b)(A). The Authority may substitute a lower turbidity value(s) if it is determined that the above limit(s) cannot achieve the required level of treatment. The water system must demonstrate to the Authority that the alternative filtration technology in combination with disinfection treatment as specified in OAR 333-061-0032 and monitored as specified by OAR 333-061-0036 consistently achieves 99.9 percent removal and/or inactivation of Giardia lamblia cysts and 99.99 percent removal and/or inactivation of viruses, and for all of those systems serving at least 10,000 people and beginning January 1, 2005 for all of those systems serving less than 10,000 people, 99 percent removal of Cryptosporidium oocysts.

(4) Maximum microbiological contaminant levels for all public water systems are as follows:

(a) The MCL is based on the presence or absence of total coliforms in a sample, rather than coliform density.

(A) For a system which collects 40 or more samples per month, total coliform-positive samples shall not exceed 5.0 percent of the samples collected during a month.

(B) For a system which collects fewer than 40 samples per month total coliform-positive samples shall not exceed more than one sample collected during a month.

(b) Any fecal coliform-positive repeat sample or E. coli-positive repeat sample, or any total coliform-positive repeat sample following a fecal coliform-positive or E. coli-positive routine sample shall be a violation of the total coliform MCL. Public notification for this potential acute health risk is prescribed in OAR 333-061-0042(2)(a)(A).

(c) All public water systems must determine compliance with the MCL for total coliforms in subsections (4)(a) and (b) of this rule on a monthly basis.

(d) A water system may demonstrate to the Authority that a violation of the total coliform MCL is due to a persistent growth of total coliforms in the distribution system rather than fecal or pathogenic contamination, a treatment lapse or deficiency, or a problem in the operation or maintenance of the distribution system. The system making the demonstration may use the health effects language of OAR 333-061-0097(4)(d) in the required public notice in addition to the mandatory language of OAR 333-061-0097(4)(a). This demonstration, made by the system in writing and submitted to the Authority for review and approval, shall show to the satisfaction of the Authority that the system meets the following conditions:

(A) No occurrence of E. coli in distribution system samples;

(B) No occurrence of coliforms at the entry point to the distribution system;

(C) The system meets treatment requirements prescribed in OAR 333-061-0032 as applicable;

(D) The system meets the turbidity MCL, if surface water sources are used;

(E) The system maintains a detectable disinfectant residual in the distribution system;

(F) The system has no history of waterborne disease outbreaks;

(G) The system has addressed requirements and recommendations of the previous sanitary survey conducted by the Authority; and

(H) The system fully complies with cross connection control program requirements.

(5) Maximum contaminant levels for radionuclides are applicable only to Community water systems and are indicated in Table 6: [Table not included. See ED. NOTE.]

(a) The average annual concentration of beta particle and photon radioactivity from man-made sources shall not produce an annual dose equivalent to the total body or any internal organ greater than 4 millirem per year according to the criteria listed in the National Bureau of Standards Handbook 69 as amended August, 1963. If two or more radionuclides are present, the sum total of their annual dose equivalent to the total body or to any organ shall not exceed 4 millirem/year.

(A) The average annual concentration of tritium assumed to produce a total body dose of 4 mrem/year is 20,000 pCi/L;

(B) The average annual concentration of strontium-90 assumed to produce a bone marrow dose of 4 mrem/year is 8 pCi/L.

(b) Compliance with the MCLs shall be calculated pursuant to OAR 333-061-0036(7)(c).

(6) Contaminant levels for secondary contaminants are applicable to all public water systems. These are indicated in Table 7. (Also note OAR 333-061-0036(8)). [Table not included. See ED. NOTE.]

(a) Violations of secondary contaminant levels for fluoride require a special public notice. Refer to OAR 333-061-0042(7).

(b) Violations of maximum contaminant levels for fluoride (4.0 mg/l) require public notification as specified in OAR 333-061-0042(2)(b)(A).

(7) Acrylamide and Epichlorohydrin. Each public water system must certify annually to the state in writing, using third party certification approved by the state or manufacturer's certification, that when acrylamide and epichlorohydrin are used in drinking water systems, the combination, or product, of dose and monomer level does not exceed the levels specified as follows:

(a) Acrylamide: 0.05 percent dosed at 1 ppm or equivalent.

(b) Epichlorohydrin: 0.01 percent dosed at 20 ppm or equivalent.

[ED. NOTE: Tables referenced are not included in rule text. Click here for PDF copy of table(s).]

Stat. Auth.: ORS 448.131
Stats. Implemented: ORS 431.110, 431.150, 448.131, 448.150 & 448.273
Hist.: HD 106, f. & ef. 2-6-76; HD 17-1981(Temp), f. & ef. 8-28-81; HD 4-1982, f. & ef. 2-26-82; Renumbered from 333-042-0210, HD 2-1983, f. & ef. 2-23-83; HD 21-1983, f. 10-20-83, ef. 11-1-83; HD 11-1985, f. & ef. 7-2-85; HD 30-1985, f. & ef 12-4-85; HD 9-1989, f. & cert, ef. 11-13-89; HD 26-1990, f. 12-26-90, cert. ef. 12-29-90; HD 9-1991(Temp), f. & cert. ef. 6-24-91; HD 1-1992, f. & cert. ef. 3-5-92; HD 7-1992, f. & cert. ef. 6-9-92; HD 12-1992, f. & cert. ef. 12-7-92; HD 3-1994, f. & cert. ef. 1-14-94; HD 11-1994, f. & cert. ef. 4-11-94; HD 1-1996, f. 1-2-96, cert. ef. 1-5-96; HD 1-1996, f. 1-2-96, cert. ef. 1-5-96; HD 14-1997, f. & cert. ef. 10-31-97; OHD 7-2000, f. 7-11-00, cert. ef. 7-15-00; OHD 23-2001, f. & cert. ef. 10-31-01; OHD 17-2002, f. & cert. ef. 10-25-02; PH 12-2003, f. & cert. ef. 8-15-03; PH 33-2004, f. & cert. ef. 10-21-04; PH 2-2006, f. & cert. ef. 1-31-06; PH 2-2008, f. & cert. ef. 2-15-08; PH 4-2009, f. & cert. ef. 5-18-09;PH 7-2010, f. & cert. ef. 4-19-10; PH 3-2013, f. & cert. ef. 1-25-13

333-061-0031

Maximum Residual Disinfectant Levels

(1) The maximum residual disinfectant levels (MRDLs) are specified as follows in Table 8: [Table not included. See ED. NOTE.]

(2) Compliance Dates:

(a) Community Water Systems and Non-Transient Non-Community Water Systems. These systems serving at least 10,000 people using either surface water or groundwater under the direct influence of surface water must comply with this rule beginning January 1, 2002. Systems serving less than 10,000 people using either surface water or groundwater under the direct influence of surface water or any system using only groundwater must comply with this rule beginning January 1, 2004.

(b) Transient Non-Community Water Systems. These systems serving at least 10,000 people using surface water or groundwater under the direct influence of surface water using chlorine dioxide as a disinfectant or oxidant must comply with this rule beginning January 1, 2002. Systems serving less than 10,000 people using surface water or groundwater under the direct influence of surface water using chlorine dioxide as a disinfectant or oxidant and systems using only groundwater not under the direct influence of surface water using chlorine dioxide as a disinfectant or oxidant must comply with this rule beginning January 1, 2004.

(3) MRDLs are enforceable in the same manner as maximum contaminant levels (MCLs) as found in OAR 333-061-0030.

[ED. NOTE: Tables referenced are not included in rule text. Click here for PDF copy of table(s).]

Stat. Auth.: ORS 448.131
Stats. Implemented: ORS 431.110, 431.150, 448.131, 448.150 & 448.273
Hist.: OHD 7-2000, f. 7-11-00, cert. ef. 7-15-00; OHD 23-2001, f. & cert. ef. 10-31-01; PH 4-2009, f. & cert. ef. 5-18-09

333-061-0032

Treatment Requirements and Performance Standards for Surface Water, Groundwater Under Direct Influence of Surface Water, and Groundwater

(1) General requirements for all public water systems supplied by a surface water source or a groundwater source under the direct influence of surface water.

(a) These regulations establish criteria under which filtration is required and treatment technique requirements in lieu of maximum contaminant levels for the following contaminants: Giardia lamblia, viruses, heterotrophic plate count bacteria, Legionella, Cryptosporidium, and turbidity. Each public water system with a surface water source or a groundwater source under the direct influence of surface water must provide treatment of that source water that complies with these treatment technique requirements. The treatment technique requirements consist of installing and properly operating water treatment processes which reliably achieve:

(A) At least 99.9 percent (3-log) removal and/or inactivation of Giardia lamblia cysts between a point where the raw water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer, and

(B) At least 99.99 percent (4-log) removal and/or inactivation of viruses between a point where the raw water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer.

(C) At least 99 percent (2-log) removal of Cryptosporidium between a point where the raw water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer for filtered systems, or Cryptosporidium control under the watershed control plan for unfiltered systems; and

(D) Compliance with any applicable disinfection profiling and benchmark requirements as specified in OAR 333-061-0036(4)(g) and OAR 333-061-0060(1)(e).

(E) Sampling and Bin Classification for Cryptosporidium:

(i) All systems must conduct an initial and second round of source water monitoring, as prescribed in subsection 333-061-0036(5)(e) of these rules, for each plant that treats a surface water or GWUDI source to determine what level, if any, of additional Cryptosporidium treatment they must provide.

(ii) Filtered systems must determine their Cryptosporidium treatment bin classification as prescribed in subsection (4)(f) of this rule and provide additional treatment for Cryptosporidium, if required, as prescribed in subsection (4)(g) of this rule. All unfiltered systems must provide treatment for Cryptosporidium as prescribed in subsections (3)(e) through (g) of this rule. Filtered and unfiltered systems must implement Cryptosporidium treatment according to the schedule in paragraph (1)(a)(F) of this rule.

(iii) Systems required to provide additional treatment for Cryptosporidium must implement microbial toolbox options that are designed and operated as prescribed in sections (13) through (17) of this rule and in OAR 333-061-0036(5)(c), OAR 333-061-0050(4) and OAR 333-061-0050(5)(k).

(F) Schedule for compliance with Cryptosporidium treatment requirements.

(i) Following initial bin classification as prescribed in subsection (4)(f) of this rule, filtered water systems must provide the level of treatment for Cryptosporidium required under subsection (4)(g) of this rule according to the schedule in subparagraph (1)(a)(F)(iii) of this rule.

(ii) Following initial determination of the mean Cryptosporidium level as prescribed by subsection (2)(d) of this rule, unfiltered water systems must provide the level of treatment for Cryptosporidium required under subsection (3)(e) of this rule according to the schedule in subparagraph (1)(a)(F)(iii) of this rule.

(iii) Cryptosporidium treatment compliance dates. The Authority may allow up to an additional two years from the date specified below for water systems making capital improvements.

(I) Water systems that serve at least 100,000 people must comply with Cryptosporidium treatment by April 1, 2012.

(II) Water systems that serve from 50,000 to 99,999 people must comply with Cryptosporidium treatment by October 1, 2012.

(III) Water systems that serve from 10,000 to 49,999 people must comply with Cryptosporidium treatment by October 1, 2013.

(IV) Water systems that serve fewer than 10,000 people must comply with Cryptosporidium treatment by October 1, 2014.

(V) State-Regulated public water systems must comply with Cryptosporidium treatment by October 1, 2015.

(iv) If the bin classification for a filtered water system changes following the second round of source water monitoring as prescribed in subsection (4)(f) of this rule, the water system must provide the level of treatment for Cryptosporidium required by subsection (4)(g) of this rule on a schedule approved by the Authority.

(v) If the mean Cryptosporidium level for an unfiltered water system changes following the second round of monitoring as prescribed by paragraph (2)(d)(A) of this rule, the water system must provide the level of Cryptosporidium treatment required by subsection (3)(e) of this rule, due to the change, following a schedule approved by the Authority.

(b) A public water system using a surface water source or a ground water source under the direct influence of surface water is considered to be in compliance with the requirements of this rule if:

(A) The system meets the requirements for avoiding filtration in section (2) of this rule and the disinfection requirements in section (3) of this rule, and the disinfection benchmarking requirements of OAR 333-061-0060(1)(e); or

(B) The system meets the filtration requirements in section (4) of this rule and the disinfection requirements in section (5) of this rule and the disinfection benchmarking requirements of OAR 333-061-0060(1)(e).

(c) Water systems that utilize sources that have been determined to be under the direct influence of surface water according to section (7) of this rule have 18 months to meet the requirements of sections (2) and (3) of this rule, or the requirements of sections (4) and (5) of this rule. During that time, the system must meet the following Interim Standards:

(A) The turbidity of water entering the distribution system must never exceed 5 NTU. Turbidity measurements must be taken a minimum of once per day. If continuous turbidimeters are in place, measurements should be taken every four hours; and

(B) Disinfection must be sufficient to reliably achieve at least 1.0 log inactivation of Giardia lamblia cysts prior to the first user. Daily disinfection "CT" values must be calculated and recorded daily, including pH and temperature measurements, and disinfection residuals at the first customer.

(C) Reports must be submitted to the Authority monthly as prescribed in OAR 333-061-0040.

(D) If these interim standards are not met, the owner or operator of the water system must notify customers of the failure as required in OAR 333-061-0042(2)(b)(A).

(2) Requirements for systems utilizing surface water or GWUDI sources without filtration:

(a) A public water system that uses a surface water source or a groundwater source under the direct influence of surface water must meet all of the conditions of this section.

(b) Source water quality conditions.

(A) The fecal coliform concentration must be equal to or less than 20/100 ml, or the total coliform concentration must be equal to or less than 100/100 ml in representative samples of the source water immediately prior to the first or only point of disinfectant application in at least 90 percent of the measurements made for the 6 previous months that the system served water to the public on an ongoing basis. If a system measures both fecal and total coliform, the fecal coliform criterion, but not the total coliform criterion, in this paragraph must be met. All samples must be collected as prescribed in OAR 333-061-0036(5)(a)(A).

(B) The turbidity level cannot exceed the maximum contaminant level prescribed in OAR 333-061-0030(3)(a)(A).

(c) Site-specific conditions. The public water supply must:

(A) Meet the disinfection requirements as prescribed in section (3) of this rule at least 11 of the 12 previous months that the system served water to the public, on an ongoing basis, unless the system fails to meet the requirements during 2 of the 12 previous months that the system served water to the public, and the Authority determines that at least one of these failures was caused by circumstances that were unusual and unpredictable.

(B) Maintain a comprehensive watershed control program which minimizes the potential for contamination by Giardia lamblia cysts, Cryptosporidium oocysts, and viruses in the source water. For groundwater systems under the direct influence of surface water, and at the discretion of the Authority, a certified drinking water protection plan (OAR 340-040-0160 to 340-040-0180) that addresses both the groundwater- and surface water components of the drinking water supply may be substituted for a watershed control program. Groundwater systems relying on a drinking water protection plan would still be subject to the requirements of subsection (c) of this rule. The watershed control program shall be developed according to guidelines in OAR 333-061-0075. The public water system must demonstrate through ownership and/or written agreements with landowners within the watershed that it can control all human activities which may have an adverse impact on the microbiological quality of the source water. The system must submit an annual report to the Authority identifying any special concerns about the watershed, the procedures used to resolve the concern, current activities affecting water quality, and projections of future adverse impacts or activities and the means to address them. At a minimum, the watershed control program must:

(i) Characterize the watershed hydrology and land ownership;

(ii) Identify watershed characteristics and activities which have or may have an adverse effect on source water quality; and

(iii) Monitor the occurrence of activities which may have an adverse effect on source water quality.

(C) Be subject to an annual on-site inspection of the watershed control program and the disinfection treatment process by the Authority. The on-site inspection must indicate to the Authority's satisfaction that the watershed control program and disinfection treatment process are adequately designed and maintained including the adequacy limiting the potential contamination by Cryptosporidium oocysts. The inspection must include:

(i) A review of the effectiveness of the watershed control program;

(ii) A review of the physical condition of the source intake and how well it is protected;

(iii) A review of the system's equipment maintenance program to ensure there is low probability for failure of the disinfection process;

(iv) An inspection of the disinfection equipment for physical deterioration;

(v) A review of operating procedures;

(vi) A review of data records to ensure that all required tests are being conducted and recorded and disinfection is effectively practiced; and

(vii) Identification of any improvements which are needed in the equipment, system maintenance and operation, or data collection.

(D) Shall not have been identified by the Authority as a source of waterborne disease outbreak under the system's current configuration. If such an outbreak occurs, the system must sufficiently modify the treatment process, as determined by the Authority, to prevent any future such occurrence.

(E) Comply with the maximum contaminant level (MCL) for total coliform bacteria in OAR 333-061-0030(4) at least 11 months of the 12 previous months that the system served water to the public on an ongoing basis, unless the Authority determines that failure to meet this requirement was not caused by a deficiency in treatment of the source water.

(F) Comply with the requirements for total trihalomethanes, haloacetic acids (five), bromate, chlorite, chlorine, chloramines, and chlorine dioxide as specified in OAR 333-061-0036(4).

(d) Determination of mean Cryptosporidium level.

(A) Unfiltered water systems must calculate the arithmetic average of all Cryptosporidium sample concentrations following completion of the initial and second round of source water monitoring conducted in accordance with OAR 333-061-0036(5)(e). Systems must report this value to the Authority for approval no later than 6 months after the date the system was required to complete the required monitoring.

(B) If the frequency of monthly Cryptosporidium sampling varies, water systems must calculate a monthly average for each month of sampling. Systems must then use these monthly average concentrations, rather than individual sample concentrations, in the calculation of the mean Cryptosporidium level prescribed in paragraph (2)(d)(A) of this rule.

(C) The report to the Authority of the mean Cryptosporidium levels calculated in accordance with paragraph (2)(d)(A) of this rule must include a summary of the source water monitoring data used for the calculation.

(D) Failure to comply with the conditions of subsection (2)(d) of this rule is a violation of the treatment technique requirement.

(e) A public water system which fails to meet any of the criteria in section (2) of this rule is in violation of a treatment technique requirement. The Authority can require filtration to be installed where it determines necessary.

(3) Disinfection requirements for systems utilizing surface water or GWUDI sources without filtration. Each public water system that does not provide filtration treatment must provide disinfection treatment as follows:

(a) The disinfection treatment must be sufficient to ensure at least 99.9 percent (3-log) inactivation of Giardia lamblia cysts and 99.99 percent (4-log) inactivation of viruses, every day the system serves water to the public, except any one day each month. Each day a system serves water to the public, the public water system must calculate the CT value(s) from the system's treatment parameters, using the procedure specified in OAR 333-061-0036(5)(a)(C) and determine whether this value(s) is sufficient to achieve the specified inactivation rates for Giardia lamblia cysts and viruses. If a system uses a disinfectant other the chlorine, the system must demonstrate to the Authority through the use of an approved protocol for on-site disinfection demonstration studies or other information satisfactory to the Authority that the system is achieving the required inactivation rates on a daily basis instead of meeting the "CT" values in this rule.

(b) Systems for chemical disinfection must have either:

(A) Redundant components, including an auxiliary power supply with automatic start-up and alarm to ensure that disinfectant application is maintained continuously while water is being delivered to the distribution system; or

(B) Automatic shut-off of delivery of water to the distribution system whenever there is less than 0.2 mg/l of residual disinfectant concentration in the water, or if the ultraviolet light system fails. If the Authority determines than automatic shut-off would cause unreasonable risk to health or interfere with fire protection, the system must comply with paragraph (3)(b)(A) of this rule.

(c) The residual disinfectant concentration in the water entering the distribution system, measured as specified in OAR 333-061-0036(5)(a)(E), cannot be less than 0.2 mg/l for more than four hours.

(d) Disinfectant residuals in the distribution system. The residual disinfectant concentration in the distribution system, measured as total chlorine, combined chlorine, or chlorine dioxide, as specified in OAR 333-061-0036(5)(a)(F), cannot be undetectable in more than 5 percent of the samples each month, for any two consecutive months that the system serves water to the public.

(e) Unfiltered water systems must provide the level of Cryptosporidium inactivation specified in this subsection, based on their mean Cryptosporidium levels, and determined in accordance with subsection (2)(d) of this rule and according to the schedule in subsection (1)(a) of this rule.

(A) Unfiltered systems with a mean Cryptosporidium level of 0.01 oocysts/L or less must provide at least 2-log Cryptosporidium inactivation.

(B) Unfiltered systems with a mean Cryptosporidium level of greater than 0.01 oocysts/L must provide at least 3-log Cryptosporidium inactivation.

(f) Inactivation treatment technology requirements. Unfiltered systems must use chlorine dioxide, ozone, or UV as prescribed by 333-061-0036(5)(c) of these rules to meet the Cryptosporidium inactivation requirements of this section.

(A) Systems that use chlorine dioxide or ozone and fail to achieve the Cryptosporidium inactivation required in subsection (3)(e) of this rule on more than one day in the calendar month are in violation of the treatment technique requirement.

(B) Systems that use UV light and fail to achieve the Cryptosporidium inactivation required in subsection (3)(e) of this rule because they do not to meet the criteria specified in subsection (18)(c) of this rule are in violation of the treatment technique requirement.

(g) Use of two disinfectants. Unfiltered water systems must meet the combined Cryptosporidium inactivation requirements of subsection (3)(e) of this rule, and the Giardia lamblia and virus inactivation requirements of subsection (3)(a) of this rule using a minimum of two disinfectants. Each of the two disinfectants must achieve by itself, the total inactivation required for at least one of the following pathogens: Cryptosporidium, Giardia lamblia, or viruses.

(4) Requirements for systems utilizing surface water or GWUDI sources that provide filtration:

(a) A public water system that uses a surface water source or a groundwater source under the direct influence of surface water, and does not meet all of the criteria in sections (1), (2), and (3) of this rule for avoiding filtration, violates a treatment technique and must provide treatment consisting of both disinfection, as specified in section (5) of this rule, and filtration treatment which complies with the requirements of either subsection (4)(b), (c), (d), or (e) of this rule by June 29, 1993 or within 18 months of the failure to meet the criteria in section (2) of this rule for avoiding filtration, whichever is later. Failure to install a required treatment by the prescribed dates is a violation of the treatment technique requirements.

(b) Conventional filtration treatment or direct filtration. Systems using conventional filtration treatment or direct filtration treatment shall meet the turbidity requirements as specified in OAR 333-0061-0030(3)(b)(A)(i) and (ii).

(c) Slow sand filtration. Systems using slow sand filtration treatment shall meet the turbidity requirements prescribed in OAR 333-061-0030(3)(b)(B).

(d) Diatomaceous earth filtration. Systems using diatomaceous earth filtration treatment shall meet the turbidity requirements prescribed in OAR 333-061-0030(3)(b)(C).

(e) Other filtration technologies. Systems using other filtration technologies shall meet the turbidity requirements prescribed in OAR 333-061-0030(3)(b)(D).

(A) GWUDI systems using bank filtration as an alternate filtration technology must meet the requirements listed in section (9) of this rule.

(B) Systems using membrane filtration must conduct continuous indirect integrity testing and daily direct integrity testing in accordance with OAR 333-061-0036(5)(d)(B) and (C).

(f) Cryptosporidium Bin classification for filtered water systems. Following completion of the initial round of source water monitoring required by OAR 333-061-0036(5)(e), filtered water systems must calculate an initial Cryptosporidium bin concentration for each plant for which monitoring was required. Calculation of the bin concentration must be based upon the Cryptosporidium results reported in accordance with OAR 333-061-0036(5)(e), and must comply with paragraphs (4)(f)(A) through (F) of this rule.

(A) For water systems that collect 48 or more samples, the bin concentration is equal to the arithmetic average of all sample concentrations.

(B) For water systems that collect at least 24 samples, but not more than 47 samples, the bin concentration is equal to the highest arithmetic average of all sample concentrations in any 12 consecutive months during which Cryptosporidium samples were collected.

(C) For water systems that serve fewer than 10,000 people and only collect Cryptosporidium samples for 12 months, i.e., collect 24 samples in 12 months, the bin concentration is equal to the arithmetic average of all sample concentrations.

(D) For water systems with plants operating only part of the year, and that monitor fewer than 12 months per year as prescribed by OAR 333-061-0036(5)(e)(E), the bin concentration is equal to the highest arithmetic average of all sample concentrations during any year of Cryptosporidium monitoring.

(E) If the monthly Cryptosporidium sampling frequency varies, water systems must first calculate a monthly average for each month of monitoring. Water systems must then use these monthly average concentrations, rather than individual sample concentrations, in the applicable calculation for bin classification of this subsection.

(F) Bin classification table.

(i) Filtered water systems must determine their initial bin classification from Table 9 as follows and using the Cryptosporidium bin concentration calculated under subsection (4)(f) of this rule: [Table not included. See ED. NOTE.]

(ii) Following completion of the second round of source water monitoring required as prescribed by OAR 333-061-0036(5)(e)(B), filtered water systems must recalculate their Cryptosporidium bin concentration based upon the sample results reported in accordance with OAR 333-061-0036(5)(e)(B) and following the procedures specified in paragraphs (4)(f)(A) through (D) of this rule. Water systems must then re-determine their bin classification using Table 9 in paragraph (4)(f)(F) of this rule. [Table not included. See ED. NOTE.]

(G) Filtered water systems must report their bin classification as prescribed by paragraph (4)(f)(F) of this rule to the Authority for approval no later than 6 months after the system is required to complete the initial and second round of source water monitoring based on the schedule in OAR 333-061-0036(5)(e)(C).

(H) The bin classification report to the Authority must include a summary of source water monitoring data and the calculation procedure used to determine bin classification. Failure to comply with the conditions of this paragraph is a violation of treatment technique requirements.

(g) Additional Cryptosporidium treatment requirements.

(A) Filtered water systems must provide the level of additional treatment for Cryptosporidium specified in Table 10 based on their bin classification as determined under subsection (4)(f) of this rule, and according to the schedule in paragraph (1)(a)(F) of this rule. [Table not included. See ED. NOTE.]

(B) Filtered water systems must use one or more of the treatment and management options listed in section (13) of this rule, termed the microbial toolbox, to comply with the additional Cryptosporidium treatment required by paragraph (4)(g)(A) of this rule.

(C) Systems classified in Bin 3 or Bin 4 must achieve at least 1-log of the additional Cryptosporidium treatment, as required by paragraph (4)(g)(A) of this rule, using either one or a combination of the following: bag filters, bank filtration, cartridge filters, chlorine dioxide, membranes, ozone, or UV, as described in sections (14) through (18) of this rule and in OAR 333-061-0036(5)(c).

(i) Failure by a water system, in any month, to achieve the treatment credit required by sections (14) through (18) of this rule and OAR 333-061-0036(5)(c) that is at least equal to the level of treatment required by paragraph (4)(g)(A) of this rule, is a violation of treatment technique requirements.

(ii) If the Authority determines during a sanitary survey or equivalent source water assessment, that after a system completed the monitoring conducted as required by OAR 333-061-0036(5)(e)(A) or (B), significant changes occurred in the system's watershed that could lead to increased contamination of the source water by Cryptosporidium, the system must take action as specified by the Authority to address the contamination. These actions may include additional source water monitoring and/or implementing microbial toolbox options specified in section (13) of this rule.

(5) Disinfection requirements for systems utilizing surface water or GWUDI sources with filtration:

(a) The disinfection treatment must be sufficient to ensure that the total treatment processes of that system achieve at least 99.9 percent (3-log) inactivation and/or removal of Giardia lamblia cysts and at least 99.99 percent (4-log) inactivation and/or removal of viruses as determined by the Authority.

(b) The residual disinfectant concentration in the water entering the distribution system, measured as specified in OAR 333-061-0036(5)(b)(B), cannot be less than 0.2 mg/l for more than 4 hours.

(c) The residual disinfectant concentration in the distribution system, measured as total chlorine, combined chlorine, or chlorine dioxide, as specified is OAR 333-061-0036(5)(b)(E) cannot be undetectable in more than 5 percent of the samples each month, for any two consecutive months that the system serves water to the public.

(6) Requirements for groundwater systems with significant deficiencies or source water fecal or total coliform contamination.

(a) Groundwater systems must comply with the treatment technique requirements of this section when a significant deficiency is identified.

(b) Groundwater systems must comply with the treatment technique requirements of this section when a groundwater source sample collected in accordance with OAR 333-061-0036(6)(r) through (t) or (w) is E. coli positive.

(c) When a significant deficiency is identified at a public water system that uses both groundwater and surface water or groundwater under the direct influence of surface water, the system must comply with provisions of this section except in cases where the Authority determines that the significant deficiency is in a portion of the distribution system that is served solely by surface water or groundwater under the direct influence of surface water.

(d) Groundwater systems must consult with the Authority regarding the appropriate corrective action within 30 days of receiving written notice from the Authority of a significant deficiency, written notice from a laboratory that a groundwater source sample collected in accordance with OAR 333-061-0036(6)(s) was found to be E. coli -positive, or direction from the Authority that an E. coli -positive collected in accordance with OAR 333-061-0036(6)(r), (u)(A), or (w) requires corrective action.

(e) Within 120 days (or earlier if directed by the Authority) of receiving written notification from the Authority of a significant deficiency, written notice from a laboratory that a groundwater source sample collected in accordance with OAR 333-061-0036(6)(s) was found to be E. coli positive, or direction from the Authority that a E. coli -positive sample collected in accordance with OAR 333-061-036(6)(r), (t), or (w) requires corrective action, the groundwater system must either:

(A) Have completed corrective action in accordance with applicable Authority plan review processes or other Authority guidance, including any Authority-specified interim measures; or

(B) Be in compliance with an Authority approved corrective action plan and schedule subject to the following conditions:

(i) Any subsequent modifications to an approved corrective action plan and schedule must be approved by the Authority; and

(ii) If the Authority specifies interim measures for the protection of public health pending Authority approval of the corrective action plan and schedule, or pending completion of the corrective action plan, the system must comply with these interim measures as well as with any schedule specified by the Authority.

(f) Groundwater systems that meet the conditions of subsections (6)(a) or (6)(b) of this rule must, upon approval by the Authority, implement one or more of the following corrective action alternatives:

(A) Correct all significant deficiencies;

(B) Disconnect the groundwater source from the water system and provide an alternate source of water. If a disconnected well is or will be within 100 feet of a public water supply well, the disconnected well must be abandoned in accordance with 333-061-0050(2)(a)(E);

(C) Eliminate the source of contamination; or

(D) Provide treatment for the groundwater source that reliably achieves at least 4-log inactivation, removal, or a combination of inactivation and removal of viruses before or at the first customer. If the groundwater source does not meet all of the applicable construction standards specified in OAR 333-061-0050(2)(a) or (b), and the Authority determines that reconstruction of the groundwater source will add a significant measure of public health protection, then the groundwater source must be made to meet all of the applicable construction standards specified in OAR 333-061-0050(2)(a) or (b) before treatment is applied as prescribed by OAR 333-061-0050(5)(b).

(g) A groundwater system with a significant deficiency is in violation of treatment technique requirements if, within 120 days (or earlier if directed by the Authority) of receiving written notice from the Authority of the significant deficiency, the water system:

(A) Does not complete corrective action in accordance with applicable Authority plan review processes or other Authority guidance, including Authority specified interim actions and measures; or

(B) Is not in compliance with an Authority approved corrective action plan and schedule.

(h) A groundwater system receiving notification of an E. coli -positive groundwater source sample (unless the Authority invalidates the sample in accordance with OAR 333-061-0036(6)(x)) is in violation of treatment technique requirements if, within 120 days (or earlier if directed by the Authority), the system:

(A) Does not complete corrective action in accordance with any applicable Authority plan review processes or other Authority guidance, including Authority specified interim actions and measures; or

(B) Is not in compliance with an Authority approved corrective action plan and schedule.

(i) A groundwater system, subject to the requirements of subsection (7)(b) of this rule, that fails to maintain at least 4-log treatment of viruses (using inactivation, removal, or an Authority approved combination of 4-log virus inactivation and removal) before or at the first customer for a groundwater source is in violation of treatment technique requirements if the failure is not corrected within four hours of determining the system is not maintaining at least 4-log treatment of viruses before or at the first customer.

(j) Water systems using groundwater sources shall provide continuous disinfection as prescribed by OAR 333-061-0050(5) when disinfection is approved by the Authority as a corrective action for a fecally contaminated source.

(7) Compliance monitoring requirements for groundwater systems that provide at least 4-log treatment of viruses. Water systems must comply with the requirements of (7)(a) through (7)(c) of this rule beginning on December 1, 2009.

(a) A groundwater system that is not required to meet the source water monitoring requirements of 333-061-0036(6)(r) through 333-061-0036(6)(u) of these rules, because it provides at least 4-log treatment of viruses (using inactivation, removal, or an Authority-approved combination of 4-log virus inactivation and removal) before or at the first customer for any groundwater source, must comply with the requirements of this subsection by December 1, 2009 or within 30 days of placing the groundwater source in service, whichever is later.

(A) The water system must notify the Authority in writing, that it provides at least 4-log treatment of viruses (using inactivation, removal, or an Authority approved combination of 4-log virus inactivation and removal) before or at the first customer for the groundwater source. Notification to the Authority must include engineering, operational, or other information that the Authority requests to evaluate the submission.

(B) The system must conduct compliance monitoring as required by subsection (7)(b) of this rule.

(C) The system must conduct groundwater source monitoring under OAR 333-061-0036(6) if the system subsequently discontinues 4-log treatment of viruses (using inactivation, removal, or an Authority-approved combination of 4-log virus inactivation and removal) before or at the first customer for the groundwater source.

(b) Monitoring requirements. A groundwater system subject to the requirements of section (6) or subsection (7)(a) of this rule must monitor the effectiveness and reliability of treatment for that groundwater source before or at the first customer as follows:

(A) Chemical Disinfection:

(i) Groundwater systems serving greater than 3,300 people must continuously monitor the residual disinfectant concentration using analytical methods as specified in OAR 333-061-0036(1), at a location approved by the Authority, and must record the lowest residual disinfectant concentration each day that water from the groundwater source is served to the public. The groundwater system must maintain the Authority-determined residual disinfectant concentration every day the groundwater system serves water from the groundwater source to the public. If there is a failure in the continuous monitoring equipment, the groundwater system must conduct grab sampling every four hours until the continuous monitoring equipment is returned to service. The system must resume continuous residual disinfectant monitoring within 14 days.

(ii) Groundwater systems serving 3,300 or fewer people must monitor the residual disinfectant concentration using analytical methods as specified in OAR 333-061-0036(1), at a location approved by the Authority, and record the residual disinfection concentration each day that water from the groundwater source is served to the public. The groundwater system must maintain the Authority-determined residual disinfectant concentration every day the groundwater system serves water from the groundwater source to the public. The groundwater system must take a daily grab sample during the hour of peak flow or at another time specified by the Authority. If any daily grab sample measurement falls below the Authority-determined residual disinfectant concentration, the groundwater system must take follow-up samples every four hours until the residual disinfectant concentration is restored to the Authority-determined level. Alternately, a groundwater system that serves 3,300 or fewer people may monitor continuously and meet the requirements of subparagraph (7)(b)(A)(i) of this rule.

(B) Membrane filtration. A groundwater system that uses membrane filtration to achieve at least 4-log removal of viruses must monitor and operate the membrane filtration process in accordance with all Authority-specified monitoring and compliance requirements. A groundwater system that uses membrane filtration is in compliance with the requirement to achieve at least 4-log removal of viruses when:

(i) The membrane has an absolute molecular weight cut-off (MWCO), or an alternate parameter describing the exclusion characteristics of the membrane, that can reliably achieve at least 4-log removal of viruses;

(ii) The membrane process is operated in accordance with Authority-specified compliance requirements; and

(iii) The integrity of the membrane is intact as verified per OAR 333-061-0050(4)(c)(J).

(C) Alternative treatment. A groundwater system that uses an Authority-approved alternative treatment to provide at least 4-log treatment of viruses (using inactivation, removal, or an Authority-approved combination of 4-log virus inactivation and removal) before or at the first customer must:

(i) Monitor the alternative treatment in accordance with all Authority-specified monitoring requirements; and

(ii) Operate the alternative treatment in accordance with all compliance requirements that the Authority determines to be necessary to achieve at least 4-log treatment of viruses.

(c) Discontinuing treatment. A groundwater system may discontinue 4-log treatment of viruses (using inactivation, removal, or an Authority-approved combination of 4-log virus inactivation and removal) before or at the first customer for a groundwater source if the Authority determines, and documents in writing, that 4-log treatment of viruses is no longer necessary for that groundwater source. A system that discontinues 4-log treatment of viruses is subject to the source water monitoring requirements of OAR 333-061-0036(6).

(8) Determination of groundwater under the direct influence of surface water (GWUDI).

(a) Except for wells using only a handpump, all groundwater sources must be evaluated for the potential of surface water influence if the source is in proximity to perennial or intermittent surface water and meets one of the hydrogeologic setting-surface water setback criteria identified in paragraph (A) and either paragraph (B) or (C). Hydrogeologic setting is identified by the Source Water Assessment or some other hydrogeologic study approved by the Authority.

(A) The groundwater source draws water from:

(i) A sand aquifer and is within 75 feet of surface water;

(ii) A sand and gravel aquifer and is within 100 feet of surface water;

(iii) A coarse sand, gravel, and boulder aquifer and is within 200 feet of surface water;

(iv) A fractured bedrock aquifer or layered volcanic aquifer and is within 500 feet of surface water; or

(v) Greater distances if geologic conditions or historical monitoring data indicate additional risk at the source; and

(B) There is a history of microbiological contamination in the source; or

(C) The Source Water Assessment or some other hydrogeologic study approved by the Authority determines the source is highly sensitive as a result of aquifer characteristics, vadose zone characteristics, monitoring history or well construction.

(b) Except as provided by subsection (8)(c) of this rule, water suppliers must conduct sampling for any groundwater source(s) meeting the criteria specified in subsection (8)(a) of this rule. Sampling must be conducted according to the following criteria:

(A) Collection of twelve consecutive monthly source water samples when the source is used year-round, or every month the source provides water to the public during one operational season for water sources used seasonally;

(B) Samples must be analyzed for E. coli in accordance with all the applicable provisions of OAR 333-061-0036(1); and

(C) Samples must be collected at the water source prior to any treatment unless the Authority approves an alternate sampling location that is representative of source water quality

(c) Public water systems that are required to evaluate their source(s) for direct influence of surface water may submit results of a hydrogeologic assessment completed by an Oregon registered geologist or other licensed professional with demonstrated experience and competence in hydrogeology in accordance with ORS 672.505 through 672.705 to demonstrate that the source is not potentially under the direct influence of surface water. The assessment must be consistent with the Oregon State Board of Geologist Examiners "Hydrology Report Guidelines," must be completed within a timeframe specified by the Authority and must include the following:

(A) Well characteristics: well depth, screened or perforated interval, casing seal placement;

(B) Aquifer characteristics: thickness of the vadose zone, hydraulic conductivity of the vadose zone and the aquifer, presence of low permeability zones in the vadose zone, degree of connection between the aquifer and surface water;

(C) Hydraulic gradient: gradient between the aquifer and surface water source during pumping conditions, variation of static water level and surface water level with time; and

(D) Groundwater flow: flow of water from the surface water source to the groundwater source during pumping conditions, estimated time-of-travel for groundwater from the surface water source(s) to the well(s), spring(s), etc.

(d) If a source water sample collected in accordance with subsection (8)(b) of this rule is reported as E. coli positive, then the water supplier must collect five additional source water samples within 24 hours of receiving notification of the positive sample result.

(e) If any of the five additional source water samples specified in subsection (8)(d) of this rule is E. coli positive then the original E. coli positive sample is considered confirmed, and the water supplier must have the groundwater source analyzed for surface water influence according to subsection (8)(h) of this rule. Further E. coli monitoring is not required.

(f) A water supplier may be required to have the groundwater source analyzed for surface water influence according to subsection (8)(h) of this rule at the discretion of the Authority if source water samples are consistently total coliform positive.

(g) Emergency groundwater sources that meet the criteria of subsection (8)(a) of this rule can either be evaluated as prescribed in subsection 8(b) or (8)(c) of this rule, or the evaluation can be waived if a Tier 2 public notice as prescribed in OAR 333-061-0042 is issued each time the source is used. The notice must explain that the source has been identified as potentially under the direct influence of surface water, but has not been fully evaluated, and therefore may not be treated sufficiently to inactivate pathogens such as Giardia lamblia and Cryptosporidium.

(h) Determination of surface water influence on a groundwater source must be based upon a minimum of two samples conducted according to the "Consensus Method for Determining Groundwaters under the Direct Influence of Surface Water Using Microscopic Particulate Analysis (MPA)." Both water samples must be collected during a period of high runoff or streamflow and separated by a period of at least four weeks, or at other times as determined by the Authority. Scoring for diatoms, other algae, and insects/larvae is partially modified according to Table 11. Scoring for Giardia lamblia, coccidia, rotifers, and plant debris remains unchanged. [Table not included. See ED. NOTE.]

(i) A water source will be classified as groundwater or GWUDI as follows:

(A) If the two initial microscopic particulate analyses have a risk score of less than 10, the water system source is classified as groundwater;

(B) If any microscopic particulate analysis (MPA) risk score is greater than 19, or each risk score is greater than 14, the water source is classified as GWUDI;

(C) If at least one of the two MPA risk scores is between 10 and 19, two additional microscopic particulate analyses must be conducted, and water source classification will be made as follows:

(i) If all of the MPA risk scores are less than 15, the water system source is classified as groundwater;

(ii) If any MPA risk score is greater than 19, or two or more are greater than 14, the water system source is classified as under the direct influence of surface water; or

(iii) If only one of four MPA risk scores is greater than 14, two additional microscopic particulate analyses must be conducted, and water source classification will be based upon further evaluation by the Authority.

(j) If an infiltration gallery, Ranney well, or dug well has been classified as groundwater under this rule, the turbidity of the source must be monitored and recorded daily and kept by the water system operator. If the turbidity exceeds 5 NTU or if the surface water body changes course such that risk to the groundwater source is increased, an MPA must be conducted at that time. Reevaluation may be required by the Authority at any time.

(k) The Authority may determine a groundwater source to be under the direct influence of surface water if the criteria in subsection (8)(a) of this rule are met and there are significant or relatively rapid shifts in groundwater characteristics, such as turbidity, which closely correlate to changes in weather or surface water conditions.

(l) The Authority may require reevaluation of a groundwater source, as specified in this section, if geologic conditions, water quality trends, or other indicators change despite any data previously collected or any determination previously made.

(m) The Authority may determine that a source is not under direct influence of surface water based on criteria other than MPAs including the Source Water Assessment, source water protection, and other water quality parameters. The determination shall be based on the criteria indicating that the water source has a very low susceptibility to contamination by parasites, including Giardia lamblia and Cryptosporidium. The Authority may impose additional monitoring or disinfection treatment requirements to ensure that the risk remains low.

(9) Requirements for groundwater sources under the direct influence of surface water seeking alternative filtration credit through bank filtration:

(a) Water systems with all MPA risk scores less than 30 may choose the option to evaluate for bank filtration credit. The water system must conduct a demonstration of performance study that includes an assessment of the ability of the local hydrogeologic setting to provide a minimum of 2-log reduction in the number of particles and microorganisms in the Giardia and Cryptosporidium size range between surface water and the groundwater source. The bank filtration study must include the following elements or other Authority approved methods:

(A) The bank filtration study must involve the collection of data on removal of biological surrogates and particles in the Cryptosporidium size range of 2–5 microns or other surrogates approved by the Authority, and related hydrogeologic and water quality parameters during the full range of operating conditions. The demonstration study methods shall be reviewed and approved by the Authority prior to implementation. Final assessment of removal credit granted to the well shall be made by the Authority based on the study results.

(b) If a GWUDI system using bank filtration as an alternative filtration technology violates the MCL for turbidity specified in OAR 333-061-0030(3)(b)(D), the water system must investigate the cause of the high turbidity within 24 hours of the exceedance. Pending the results of the investigation by the water system, the Authority may require a new bank filtration study.

(10) Disinfection Byproduct Control Requirements:

(a) This rule establishes criteria under which community water systems and Non-transient, Non-community water systems which add a chemical disinfectant to the water in any part of the drinking water treatment process must modify their practices to meet MCLs and MRDLs in OAR 333-061-0030 and 0031, respectively. This rule also establishes the treatment technique requirements for disinfection byproduct precursors, and the criteria under which transient non-community water systems that use chlorine dioxide as a disinfectant or oxidant must modify their practices to meet the MRDL for chlorine dioxide as specified in OAR 333-061-0031.

(b) Compliance dates.

(A) Community and Non-transient Non-community water systems serving at least 10,000 people using surface water or groundwater under the direct influence of surface water must comply with the treatment technique requirements of this rule as well as monitoring and maximum contaminants requirements for disinfection byproduct control as specified in OAR 333-061-0030 and 0036, respectively beginning January 1, 2002. Those systems serving fewer than 10,000 people using surface water or groundwater under the direct influence of surface water and those systems using only groundwater not under the direct influence of surface water must comply with the rules identified in this paragraph beginning January 1, 2004.

(B) Transient non-community water systems serving at least 10,000 people using surface water or groundwater under the direct influence of surface water and using chlorine dioxide as a disinfectant or oxidant must comply with the requirements for chlorine dioxide in this rule and OAR 333-061-0030 and 0036 beginning January 1, 2002. Those systems serving fewer than 10,000 persons using surface water or groundwater under the direct influence of surface water and using chlorine dioxide as a disinfectant or oxidant and systems using only ground water not under the direct influence of surface water and using chlorine dioxide as a disinfectant or oxidant must comply with the requirements for chlorine dioxide in this rule and OAR 333-061-0030 and 0036 beginning January 1, 2004.

(c) Water systems may increase residual disinfectant levels in the distribution system of chlorine or chloramines (but not chlorine dioxide) to a level and for a time necessary to protect public health, to address specific microbiological contamination problems caused by circumstances such as, but not limited to, distribution line breaks, storm run-off events, source water contamination events, or cross connection events.

(d) Enhanced coagulation or enhanced softening are authorized treatment techniques to control the level of disinfection byproduct precursors for water systems using surface water or groundwater under the direct influence of surface water and conventional filtration treatment. Community and Non-transient Non-community water systems using conventional filtration treatment must operate with enhanced coagulation or enhanced softening to achieve the total organic carbon (TOC) percent removal levels specified in subsection (10)(e) of this rule unless the system meets at least one of the alternative compliance criteria listed in paragraph (10)(d)(A) or (10)(d)(B) of this rule.

(A) Alternative compliance criteria for enhanced coagulation and enhanced softening systems. Water systems may use the alternative compliance criteria in subparagraphs (10)(d)(A)(i) through (vi) of this rule in lieu of complying with the performance criteria specified in subsection (e) of this section. Systems must still comply with monitoring requirements specified in OAR 333-061-0036(4)(n).

(i) The system's source water TOC level is less than 2.0 mg/L, calculated quarterly as a running annual average.

(ii) The system's treated water TOC level is less than 2.0 mg/L, calculated quarterly as a running annual average.

(iii) The system's source water TOC is less than 4.0 mg/L, calculated quarterly as a running annual average; the source water alkalinity is greater than 60 mg/L (as CaCO3 calculated quarterly as a running annual average; and the TTHM and HAA5 running annual averages are no greater than 0.040 mg/L and 0.030 mg/L, respectively.

(iv) The TTHM and HAA5 running annual averages are no greater than 0.040 mg/L and 0.030 mg/L, respectively, and the system uses only chlorine for primary disinfection and maintenance of a residual in the distribution system.

(v) The system's source water SUVA, prior to any treatment and measured monthly is less than or equal to 2.0 L/mg-m, calculated quarterly as a running annual average.

(vi) The system's finished water SUVA, measured monthly is less than or equal to 2.0 L/mg-m, calculated quarterly as a running annual average.

(B) Additional alternative compliance criteria for softening systems. Systems practicing enhanced softening that cannot achieve the TOC removals required by paragraph (10)(e)(B) of this rule may use the alternative compliance criteria in subparagraphs (10)(d)(B)(i) and (ii) of this rule in lieu of complying with subsection (10)(e) of this rule. Systems must still comply with monitoring requirements in specified in OAR 333-061-0036(4)(n).

(i) Softening that results in lowering the treated water alkalinity to less than 60 mg/L (as CaCO3), measured monthly and calculated quarterly as a running annual average.

(ii) Softening that results in removing at least 10 mg/L of magnesium hardness (as CaCO3), measured monthly and calculated quarterly as a running annual average.

(e) Enhanced coagulation and enhanced softening performance requirements.

(A) Systems must achieve the percent reduction of TOC specified in paragraph (10)(e)(B) in this rule between the source water and the combined filter effluent, unless the Authority approves a system's request for alternate minimum TOC removal (Step 2) requirements under paragraph (10)(e)(C) of this rule.

(B) Required Step 1 TOC reductions, specified in Table 12, are based upon specified source water parameters. Systems practicing softening are required to meet the Step 1 TOC reductions in the far-right column (Source water alkalinity >120 mg/L) for the specified source water TOC: [Table not included. See ED. NOTE.]

(C) Water systems that cannot achieve the Step 1 TOC removals required by paragraph (10)(e)(B) of this rule due to water quality parameters or operational constraints must apply to the Authority, within three months of failure to achieve the TOC removals required by paragraph (10)(e)(B) of this rule, for approval of alternative minimum TOC (Step 2) removal requirements submitted by the water system. If the Authority approves the alternative minimum TOC removal (Step 2) requirements, the Authority may make those requirements retroactive for the purposes of determining compliance. Until the Authority approves the alternate minimum TOC removal (Step 2) requirements, the water system must meet the Step 1 TOC removals contained in paragraph (10)(e)(B) of this rule.

(D) Alternate minimum TOC removal (Step 2) requirements. Applications made to the Authority by enhanced coagulation systems for approval of alternative minimum TOC removal (Step 2) requirements under paragraph (10)(e)(C) of this rule must include, as a minimum, results of bench-scale or pilot-scale testing conducted under subparagraph (10)(e)(D)(i) of this rule. The submitted bench-scale or pilot scale testing must be used to determine the alternate enhanced coagulation level.

(i) Alternate enhanced coagulation level is defined as coagulation at a coagulant dose and pH as determined by the method described in subparagraphs (10)(e)(D)(i) through (v) of this rule such that an incremental addition of 10 mg/L of alum (or equivalent amount of ferric salt) results in a TOC removal of less than or equal to 0.3 mg/ L. The percent removal of TOC at this point on the "TOC removal versus coagulant dose" curve is then defined as the minimum TOC removal required for the system. Once approved by the Authority, this minimum requirement supersedes the minimum TOC removal required by the Table 12 in paragraph (10)(e)(B) of this rule. This requirement will be effective until such time as the Authority approves a new value based on the results of a new bench-scale and pilot-scale test. Failure to achieve Authority-set alternative minimum TOC removal levels is a violation. [Table not included. See ED. NOTE.]

(ii) Bench-scale or pilot-scale testing of enhanced coagulation must be conducted by using representative water samples and adding 10 mg/L increments of alum (or equivalent amounts of ferric salt) until the pH is reduced to a level less than or equal to the enhanced coagulation Step 2 target pH as specified in Table 13: [Table not included. See ED. NOTE.]

(iii) For waters with alkalinities of less than 60 mg/L for which addition of small amounts of alum or equivalent addition of iron coagulant drives the pH below 5.5 before significant TOC removal occurs, the system must add necessary chemicals to maintain the pH between 5.3 and 5.7 in samples until the TOC removal of 0.3 mg/L per 10 mg/L alum added (or equivalent addition of iron coagulant) is reached.

(iv) The system may operate at any coagulant dose or pH necessary, consistent with these rules to achieve the minimum TOC percent removal approved under paragraph (10)(e)(C) of this rule.

(v) If the TOC removal is consistently less than 0.3 mg/L of TOC per 10 mg/L of incremental alum dose at all dosages of alum (or equivalent addition of iron coagulant), the water is deemed to contain TOC not amenable to enhanced coagulation. The water system may then apply to the Authority for a waiver of enhanced coagulation requirements.

(f) Compliance calculations.

(A) Water systems other than those identified in paragraphs (10)(d)(A) or (d)(B) of this rule must comply with requirements contained in paragraph (10)(e)(B) or (C) of this rule. Systems must calculate compliance quarterly, beginning after the system has collected 12 months of data, by determining an annual average using the following method:

(i) Determine actual monthly TOC percent removal, equal to: {1- (treated water TOC/source water TOC)}x100

(ii) Determine the required monthly TOC percent removal (from either Table 9 in paragraph (10)(e)(B) of this rule or from paragraph (10)(e)(C) of this rule). [Table not included. See ED. NOTE.]

(iii) Divide the value in subparagraph (10)(f)(A)(i) of this rule by the value in subparagraph (10)(f)(A)(ii) of this rule.

(iv) Add together the results of subparagraph (10)(f)(A)(iii) of this rule for the last 12 months and divide by 12.

(v) If the value calculated in subparagraph (10)(f)(A)(iv) of this rule is less than 1.00, the water system is not in compliance with the TOC percent removal requirements.

(B) Water systems may use the provisions in subparagraphs (10)(f)(B)(i) through (v) of this rule in lieu of the calculations in subparagraph (10)(f)(A)(i) through (v) of this rule to determine compliance with TOC percent removal requirements.

(i) In any month that the water system's treated or source water TOC level is less than 2.0 mg/L, the water system may assign a monthly value of 1.0 (in lieu of the value calculated in subparagraph (10)(f)(A)(iii) of this rule) when calculating compliance under the provisions of paragraph (10)(f)(A) of this rule.

(ii) In any month that a system practicing softening removes at least 10 mg/L of magnesium hardness (as CaCO3), the water system may assign a monthly value of 1.0 (in lieu of the value calculated in subparagraph (10)(f)(A)(iii) of this rule) when calculating compliance under the provisions of paragraph (10)(f)(A) of this rule.

(iii) In any month that the water system's source water SUVA, prior to any treatment is less than or equal to 2.0 L/mg-m, the water system may assign a monthly value of 1.0 (in lieu of the value calculated in subparagraph (10)(f)(A)(iii) of this rule) when calculating compliance under the provisions of paragraph (10)(f)(A) of this rule.

(iv) In any month that the water system's finished water SUVA is less than or equal to 2.0 L/mg-m, the system may assign a monthly value of 1.0 (in lieu of the value calculated in subparagraph (10)(f)(A)(iii) of this rule) when calculating compliance under the provisions of paragraph (10)(f)(A) of this rule.

(v) In any month that a system practicing enhanced softening lowers alkalinity below 60 mg/L (as CaCO3), the water system may assign a monthly value of 1.0 (in lieu of the value calculated in subparagraph (10)(f)(A)(iii) of this rule) when calculating compliance under the provisions of paragraph (10)(f)(A) of this rule.

(C) Water systems using conventional treatment may also comply with the requirements of this section by meeting the criteria in paragraph (10)(d)(A) or (B) of this rule.

(11) Requirements for Water Treatment Plant Recycled Water.

(a) Any water system using surface water or groundwater under the direct influence of surface water that uses conventional filtration treatment or direct filtration treatment and that recycles spent filter backwash water, thickener, supernatant, or liquids from dewatering processes must meet the requirements of subsections (10)(b) and (c) of this rule and OAR 333-061-0040(2)(i).

(b) A water system must notify the Authority in writing by December 8, 2003 if that water system recycles spent filter backwash water, thickener supernatant, or liquids from dewatering processes. This notification must include, at a minimum, the information specified in paragraphs (10)(b)(A) and (B) of this rule.

(A) A water treatment plant schematic showing the origin of all flows which are recycled (including, but not limited to, spent filter backwash water, thickener supernatant, and liquids from dewatering processes), the hydraulic conveyance used to transport them, and the location where they are re-introduced back into the water treatment plant.

(B) Typical recycle flow in gallons per minute (gpm), the highest observed water treatment plant flow experienced in the previous year (gpm), the design flow for the water treatment plant (gpm), and the operating capacity of the water treatment plant (gpm) that has been determined by the Authority where the Authority has made such determinations.

(c) Any water system that recycles spent filter backwash water, thickener supernatant, or liquids from dewatering processes must return these flows through the processes of a system's existing conventional filtration treatment plant or direct filtration treatment plant as defined by these rules or at an alternate location approved by the Authority by June 8, 2004. If capital improvements are required to modify the recycle location to meet this requirement, all capital improvements must be completed no later than June 8, 2006.

(12) Water systems using uncovered finished water storage facilities must comply with the conditions of either subsections (12)(a) or (b) of this rule for each uncovered finished water storage facility, or be in compliance with an Authority approved schedule to meet these conditions no later than April 1, 2009.

(a) Water systems must cover any uncovered finished water storage facility; or

(b) Treat the discharge from the uncovered finished water storage facility into the distribution system to achieve at least 4-log virus, 3-log Giardia lamblia, and 2-log Cryptosporidium inactivation and/or removal using a protocol approved by the Authority.

(c) Failure to comply with the requirements of this section is a violation of the treatment technique requirement.

(13) Summary and General Requirements of Microbial toolbox options for meeting Cryptosporidium treatment requirements. Filtered water systems are eligible for the treatment credits listed in Table 14 of this section by meeting the conditions for microbial toolbox options described in sections (14) through (18) of this rule and in OAR 333-061-0036(5)(c). Unfiltered water systems are eligible only for the treatment credits specified as inactivation toolbox options in Table 14. Water systems apply these treatment credits to meet the requirements of subsections (3)(e) or (4)(g) of this rule, as applicable. [Table not included. See ED. NOTE.]

(14) Source toolbox components for meeting Cryptosporidium treatment requirements.

(a) Watershed control program. Water systems receive 0.5-log Cryptosporidium treatment credit for implementing a watershed control program that meets the requirements of this subsection.

(A) Water systems must notify the Authority of the intent to apply for the watershed control program credit no later than two years prior to the treatment compliance date applicable to the system in subsection (1)(a) of this rule.

(B) Water systems must submit a proposed watershed control plan to the Authority no later than one year before the applicable treatment compliance date in subsection (1)(a) of this rule. The Authority must approve the watershed control plan for the water system to receive the applicable treatment credit. The watershed control plan must include the following elements:

(i) Identification of an area of influence, outside of which the likelihood of Cryptosporidium or fecal contamination affecting the treatment plant intake is not significant. This is the area to be evaluated in future watershed surveys under subparagraph (14)(a)(E)(ii) of this rule;

(ii) Identification of both potential and actual sources of Cryptosporidium contamination, and an assessment of the relative impact of these contamination sources on the water system’s source water quality;

(iii) An analysis of the effectiveness and feasibility of control measures that could reduce Cryptosporidium loading from sources of contamination to the system’s source water; and

(iv) A statement of goals and specific actions the system will undertake to reduce source water Cryptosporidium levels. The plan must explain how the actions are expected to contribute to specific goals, identify watershed partners and their roles, identify resource requirements and commitments, and include a schedule for plan implementation with deadlines for completing specific actions identified in the plan.

(C) Water Systems with existing watershed control programs are eligible to seek this credit, but must meet the requirements prescribed in paragraph (14)(a)(B) of this rule, and must specify ongoing and future actions that will reduce source water Cryptosporidium levels.

(D) If the Authority does not respond to a water system regarding approval of a watershed control plan submitted in accordance with this section, and the system meets the other requirements of this section, the watershed control program will be considered approved and a 0.5 log Cryptosporidium treatment credit will be awarded unless the Authority subsequently withdraws such approval.

(E) Water systems must complete the actions specified in this paragraph to maintain the 0.5-log credit.

(i) Water systems must submit an annual watershed control program status report to the Authority. The status report must describe the water system’s implementation of the approved plan, and assess the adequacy of the plan to meet its goals. It must explain how the water system is addressing any deficiencies in plan implementation, including those previously identified by the Authority, or as the result of the watershed survey conducted in accordance with subparagraph (14)(a)(E)(ii) of this rule. The watershed control program status report must also describe any significant changes that have occurred in the watershed since the last watershed sanitary survey.

(ii) Water systems must undergo a watershed sanitary survey every three years for community water systems and every five years for non-community water systems and submit the survey report to the Authority. The survey must be conducted according to Authority guidelines and by persons the Authority approves.

(I) The watershed sanitary survey must meet the following criteria: encompass the region identified in the Authority approved watershed control plan as the area of influence; assess the implementation of actions to reduce source water Cryptosporidium levels; and identify any significant new sources of Cryptosporidium.

(II) If the Authority determines that significant changes may have occurred in the watershed since the previous watershed sanitary survey, water systems must undergo another watershed sanitary survey by a date determined by the Authority regardless of the regular date specified in subparagraph (14)(a)(E)(ii) of this rule.

(iii) The water system must make the watershed control plan, annual status reports, and watershed sanitary survey reports available to the public upon request. These documents must be in a plain language style and include criteria by which to evaluate the success of the program in achieving plan goals. The Authority may approve withholding portions of the annual status report, watershed control plan, and watershed sanitary survey from the public based on water supply security considerations.

(F) If the Authority determines that a water system is not implementing the approved watershed control plan, the Authority may withdraw the watershed control program treatment credit.

(G) If a water system determines, during implementation, that making a significant change to its approved watershed control program is necessary, the system must notify the Authority prior to making any such changes. If any change is likely to reduce the level of source water protection, the system must notify the Authority of the actions the water system will take to mitigate this effect.

(b) Alternative source. A water system may conduct source water monitoring that reflects a different intake location (either in the same source or from an alternate source), or a different procedure for the timing or level of withdrawal from the source. If the Authority approves, a system may determine its bin classification under subsection (4)(f) of this rule based on the alternative source monitoring results.

(A) If a water system conducts alternative source monitoring as prescribed by this subsection, the water system must also monitor their current plant intake concurrently as prescribed by OAR 333-061-0036(5)(e).

(B) Alternative source monitoring as prescribed by this subsection must meet the requirements for source monitoring to determine bin classification, as described in OAR 333-061-0036(1), OAR 333-061-0036(5)(e) through (g), and OAR 333-061-0040(1)(l). Water systems must report the alternative source monitoring results to the Authority, including supporting information that documents the operating conditions under which the samples were collected.

(C) If a system determines its bin classification according to subsection (4)(f) of this rule using alternative source monitoring results that reflect a different intake location or a different procedure for managing the timing or level of withdrawal from the source, the system must relocate the intake or permanently adopt the withdrawal procedure, as applicable, no later than the applicable treatment compliance date in subsection (1)(a) of this rule.

(15) Pre-filtration treatment toolbox components for meeting Cryptosporidium treatment requirements.

(a) Presedimentation. Systems receive 0.5-log Cryptosporidium treatment credit for a presedimentation basin during any month the process meets the criteria specified in this paragraph:

(A) The presedimentation basin must be in continuous operation, and must treat the entire plant flow taken from a surface water or GWUDI source;

(B) The water system must continuously add a coagulant to the presedimentation basin; and

(C) The presedimentation basin must achieve the performance criteria specified in this paragraph.

(i) The basin must demonstrate at least 0.5-log mean reduction of influent turbidity. This reduction must be determined using daily turbidity measurements of the presedimentation process influent and effluent, and must be calculated as follows: log10(monthly mean of daily influent turbidity)-log10(monthly mean of daily effluent turbidity).

(ii) The basin must also comply with Authority-approved performance criteria that demonstrates at least 0.5-log mean removal of micron-sized particulate material through the presedimentation process.

(b) Two-stage lime softening. Systems receive an additional 0.5-log Cryptosporidium treatment credit for a two-stage lime softening plant if chemical addition and hardness precipitation occur in two separate and sequential softening stages prior to filtration. Both softening stages must treat the entire plant flow taken from a surface water or GWUDI source.

(c) Bank filtration. Water systems receive Cryptosporidium treatment credit for bank filtration that serves as pretreatment to a filtration plant by meeting the criteria specified in this section. Water systems using bank filtration when they begin source water monitoring according to OAR 333-061-0036(5)(e) must collect samples as prescribed by OAR 333-061-0036(5)(g) and are not eligible for this credit.

(A) Wells with a groundwater flow path of at least 25 feet receive 0.5-log treatment credit. Wells with a groundwater flow path of at least 50 feet receive 1.0-log treatment credit. The groundwater flow path must be determined as specified in paragraph (D) of this subsection.

(B) Only wells in granular aquifers are eligible for treatment credit. Granular aquifers are those comprised of sand, clay, silt, rock fragments, pebbles or larger particles, and minor cement. A water system must characterize the aquifer at the well site to determine aquifer properties.

(i) Water systems must extract a core from the aquifer and demonstrate that in at least 90 percent of the core length, grains less than 1.0 mm in diameter constitute at least 10 percent of the core material.

(C) Only horizontal and vertical wells are eligible for treatment credit.

(D) For vertical wells, the groundwater flow path is the measured distance from the edge of the surface water body under high flow conditions (as determined by the 100 year floodplain elevation boundary or by the floodway, as defined in Federal Emergency Management Agency flood hazard maps) to the well screen. For horizontal wells, the groundwater flow path is the measured distance from the bed of the river under normal flow conditions to the closest horizontal well lateral screen.

(E) Water systems must monitor each wellhead for turbidity at least once every four hours while the bank filtration process is in operation. If monthly average turbidity levels, based on daily maximum values in the well, exceed 1 NTU, the system must report this result to the Authority and conduct an assessment within 30 days to determine the cause of the high turbidity levels in the well. If the Authority determines that microbial removal has been compromised, the Authority may revoke treatment credit until the water system implements Authority-approved corrective actions to remediate the problem.

(F) Springs and infiltration galleries are not eligible for treatment credit under this section, but are eligible for a treatment credit in accordance with subsection (16)(c) of this rule.

(G) Bank filtration demonstration of performance. The Authority may approve Cryptosporidium treatment credit for bank filtration based on a demonstration of performance study that meets the criteria in this paragraph. This treatment credit may be greater than 1.0-log and may be awarded to bank filtration that does not meet the criteria in (15)(c)(A) through (E) of this rule.

(i) The study must follow an Authority approved protocol, and must include the collection of data on the removal of Cryptosporidium or a surrogate for Cryptosporidium and related hydrogeologic and water quality parameters during the full range of operating conditions.

(ii) The study must include sampling from both the production well(s) and monitoring wells that are screened and located along the shortest flow path between the surface water source and the production well(s).

(16) Treatment performance toolbox components for meeting Cryptosporidium treatment requirements.

(a) Combined filter performance. Water systems using conventional filtration treatment or direct filtration treatment receive an additional 0.5-log Cryptosporidium treatment credit during any month that the water system meets the criteria in this subsection. Combined filter effluent (CFE) turbidity must be less than or equal to 0.15 NTU in at least 95 percent of the measurements. Turbidity must be measured as described in OAR 333-061-0036(5)(a)(B).

(b) Individual filter performance. Water systems using conventional filtration treatment or direct filtration treatment receive 0.5-log Cryptosporidium treatment credit, which can be in addition to the 0.5-log credit under subsection (16)(a) of this rule, during any month the system meets the criteria in this subsection. Compliance with this criteria must be based on individual filter turbidity monitoring as described in OAR 333-061-0036(5)(d).

(A) The filtered water turbidity for each individual filter must be less than or equal to 0.15 NTU in at least 95 percent of the measurements recorded each month.

(B) No individual filter may have a measured turbidity greater than 0.3 NTU in two consecutive measurements taken 15 minutes apart.

(C) Any system that has received treatment credit for individual filter performance and fails to meet the requirements of paragraphs (16)(b)(A) or (B) of this rule, during any month, is in violation of treatment technique requirements as prescribed by subsection (4)(g) of this rule unless the Authority determines the following:

(i) The failure was due to unusual and short-term circumstances that could not reasonably be prevented through optimizing treatment plant design, operation, or maintenance; and

(ii) The system has experienced no more than two such failures in any calendar year.

(c) Demonstration of performance. The Authority may approve Cryptosporidium treatment credit for water treatment processes based on a demonstration of performance study that meets the criteria in this subsection. This treatment credit may be greater than or less than the prescribed treatment credits in subsection (4)(g) or sections (15) through (18) of this rule and may be awarded to treatment processes that do not meet the criteria for the prescribed credits.

(A) Water systems cannot receive the prescribed treatment credit for any toolbox option in sections (15) through (18) of this rule, if that toolbox option is included in a demonstration of performance study for which treatment credit is awarded under this subsection.

(B) The demonstration of performance study must follow an Authority approved protocol, and must demonstrate the level of Cryptosporidium reduction achieved by the treatment process under the full range of expected operating conditions for the water system.

(C) Approval by the Authority must be in writing, and may include monitoring and treatment performance criteria that the system must demonstrate and report on an ongoing basis to remain eligible for the treatment credit. The Authority may require such criteria where necessary to verify that the conditions under which the demonstration of performance credit was approved are maintained during routine operation.

(17) Additional filtration toolbox components for meeting Cryptosporidium treatment requirements.

(a) Bag and cartridge filters. Systems receive Cryptosporidium treatment credit of up to 2.0-log for individual bag or cartridge filters and up to 2.5-log for bag or cartridge filters operated in series by meeting the requirements in OAR 333-061-0050(4)(c)(J). To be eligible for this credit, water systems must report to the Authority, the results of challenge testing conducted in accordance with OAR 333-061-0050(4)(c)(J). The filters must treat the entire plant flow.

(b) Membrane filtration. Systems receive Cryptosporidium treatment credit for membrane filtration that meets the requirements of this paragraph. Membrane cartridge filters that meet the definition of membrane filtration in OAR 333-061-0020(122) are eligible for this credit. The level of treatment credit a system receives is equal to the lower of the values determined under OAR 333-061-0050(4)(c)(H)(i) and (ii).

(c) Second stage filtration. Water systems receive 0.5-log Cryptosporidium treatment credit for a separate second stage of Authority-approved filtration that consists of sand, dual media, GAC, or other fine grain media following granular media filtration. To be eligible for this credit, the first stage of filtration must be preceded by a coagulation step and, both filtration stages must treat the entire plant flow taken from a surface water or GWUDI source. The Authority must assign the treatment credit based on an assessment of the design characteristics of the filtration process. A cap (added layer of filter media), such as GAC, on a single stage of filtration is not eligible for this credit.

(d) Slow sand filtration (as secondary filter). Water systems are eligible to receive 2.5-log Cryptosporidium treatment credit for a slow sand filtration process that follows a separate stage of filtration if both filtration stages treat the entire plant flow taken from a surface water or GWUDI source, and no disinfectant residual is present in the influent water to the slow sand filtration process. The Authority must assign the treatment credit based on an assessment of the design characteristics of the filtration process. This subsection does not apply to treatment credit awarded to slow sand filtration used as a primary filtration process.

(18) Inactivation toolbox components for meeting Cryptosporidium treatment requirements.

(a) If Chlorine Dioxide is used, CT values in Table 36 must be met. [Table not included. See ED. NOTE.]

(b) If Ozone is used, CT values in Table 37 must be met. [Table not included. See ED. NOTE.]

(c) To receive treatment credit for UV light, water systems must treat at least 95 percent of the water delivered to the public during each month by UV reactors operating within validated conditions for the required UV dose, as prescribed by OAR 333-061-0036(5)(c)(D) and OAR 333-061-0050(5)(k)(I). Systems must demonstrate compliance with this condition by the monitoring required in OAR 333-061-0036(5)(c)(D)(ii).

[ED. NOTE: Tables referenced are not included in rule text. Click here for PDF copy of table(s).]

Stat. Auth.: ORS 448.131
Stats. Implemented: ORS 431.110, 431.150, 448.175 & 448.273
Hist.: HD 26-1990, f. 12-26-90, cert. ef. 12-29-90; HD 7-1992, f. & cert. ef. 6-9-92; HD 12-1992, f. & cert. ef. 12-7-92; HD 14-1997, f. & cert. ef. 10-31-97; OHD 4-1999, f. 7-14-99, cert. ef. 7-15-99; OHD 7-2000, f. 7-1-00, cert. ef. 7-15-00; OHD 23-2001, f. & cert. ef. 10-31-01; OHD 17-2002, f. & cert. ef. 10-25-02; PH 12-2003, f. & cert. ef. 8-15-03; PH 33-2004, f. & cert. ef. 10-21-04; PH 2-2006, f. & cert. ef. 1-31-06; PH 2-2008, f. & cert. ef. 2-15-08; PH 4-2009, f. & cert. ef. 5-18-09; PH 7-2010, f. & cert. ef. 4-19-10; PH 13-2012, f. & cert. ef. 9-10-12; PH 3-2013, f. & cert. ef. 1-25-13

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