R317-1-3. Requirements for Waste Discharges

  3.1 Compliance With Water Quality Standards.

  All persons discharging wastes into any of the waters of the State shall provide the degree of wastewater treatment determined necessary to insure compliance with the requirements of Rule R317-2 Water Quality Standards, except that the Director may waive compliance with these requirements for specific criteria listed in Rule R317-2 where it is determined that the designated use is not being impaired or significant use improvement would not occur or where there is a reasonable question as to the validity of a specific criterion or for other valid reasons as determined by the Director.

  3.2 Compliance With Secondary Treatment Requirements.

  All persons discharging wastes from point sources into any of the waters of the State shall provide treatment processes which will produce secondary effluent meeting or exceeding the following effluent quality standards.

  A. The arithmetic mean of BOD values determined on effluent samples collected during any 30-day period shall not exceed 25 mg/L, nor shall the arithmetic mean exceed 35 mg/L during any 7-day period. In addition, if the treatment plant influent is of domestic or municipal sewage origin, the BOD values of effluent samples shall not be greater than 15% of the BOD values of influent samples collected in the same time period. As an alternative, if agreed to by the person discharging wastes, the following effluent quality standard may be established as a requirement of the discharge permit and must be met: The arithmetic mean of CBOD values determined on effluent samples collected during any 30-day period shall not exceed 20 mg/L nor shall the arithmetic mean exceed 30 mg/L during any 7-day period. In addition, if the treatment plant influent is of domestic or municipal sewage origin, the CBOD values of effluent samples shall not be greater than 15% of the CBOD values of influent samples collected in the same time period.

  B. The arithmetic mean of SS values determined on effluent samples collected during any 30-day period shall not exceed 25 mg/L, nor shall the arithmetic mean exceed 35 mg/L during any 7-day period. In addition, if the treatment plant influent is of domestic or municipal sewage origin, the SS values of effluent samples shall not be greater than 15% of the SS values of influent samples collected in the same time period.

  C. The geometric mean of total coliform and fecal coliform bacteria in effluent samples collected during any 30-day period shall not exceed either 2000 per 100 mL or 200 per 100 mL respectively, nor shall the geometric mean exceed 2500 per 100 mL or 250 per 100 mL respectively, during any 7-day period; or, the geometric mean of E. coli bacteria in effluent samples collected during any 30-day period shall not exceed 126 per 100 mL nor shall the geometric mean exceed 158 per 100 mL respectively during any 7-day period. Exceptions to this requirement may be allowed by the Director where domestic wastewater is not a part of the effluent and where water quality standards are not violated.

  D. The effluent values for pH shall be maintained within the limits of 6.5 and 9.0.

  E. Exceptions to the 85% removal requirements may be allowed where infiltration makes such removal requirements infeasible and where water quality standards are not violated.

  F. The Director may allow exceptions to the requirements of Subsections R317-1-3.2.A, R317-1-3.2.B, and R317-1-3.2.D where the discharge will be of short duration and where there will be no significant detrimental effect on receiving water quality or downstream beneficial uses.

  G. The Director may allow that the BOD5 and TSS effluent concentrations for discharging domestic wastewater lagoons shall not exceed 45 mg/L for a monthly average nor 65 mg/L for a weekly average provided the following criteria are met:

  1. the lagoon system is operating within the organic and hydraulic design capacity established by Rule R317-3;

  2. the lagoon system is being properly operated and maintained;

  3. the treatment system is meeting all other permit limits;

  4. there are no significant or categorical industrial users (IU) defined by 40 CFR Part 403, unless it is demonstrated to the satisfaction of the Director that the IU is not contributing constituents in concentrations or quantities likely to significantly affect the treatment works; and

  5. a Waste Load Allocation (WLA) indicates that the increased permit limits would not impair beneficial uses of the receiving stream.

  3.3 Technology-based Limits for Controlling Phosphorus Pollution.

  A. Technology-based Phosphorus Effluent Limits (TBPEL)

  1. All non-lagoon treatment works discharging wastewater to surface waters of the state shall provide treatment processes which will produce effluent less than or equal to an annual mean of 1.0 mg/L for total phosphorus.

  2. The TBPEL shall be achieved by January 1, 2020, or no later than January 1, 2025, after a variance has been granted under Subsection R317-1-3.3.C.1.e.

  B. Discharging Lagoons -Phosphorus Loading Cap

  1. No TBPEL will be instituted for discharging treatment lagoons. Instead, each discharging lagoon will be evaluated to determine the current annual average total phosphorus load measured in pounds per year based on monthly average flow rates and concentrations. Absent field data to determine these loads, and in case of intermittent discharging lagoons, the phosphorus load cap will be estimated by the Director.

  2. A cap of 125% of the current annual total phosphorus load will be established and referred to as phosphorus loading cap. Once the lagoon's phosphorus loading cap has been reached, the owner of the facility will have five years to construct treatment processes or implement treatment alternatives to prevent the total phosphorus loading cap from being exceeded.

  3. The load cap shall become effective July 1, 2018.

  C. Variances for TBPEL and Phosphorus Loading Caps

  1. The Director may authorize a variance to the TBPEL or phosphorus loading cap under any of the following conditions:

  a. Where an existing TMDL has allocated a total phosphorus wasteload to a treatment works, no TBPEL or phosphorus loading cap, as applicable, will be applied.

  b. If the owner of a discharging treatment works can demonstrate that imposing the TBPEL or phosphorus loading cap would result in an economic hardship, an alternative TBPEL or phosphorus loading cap that would not cause economic hardship may be applied. "Economic hardship" for a publicly owned treatment works is defined as sewer service costs that, as a result of implementing a TBPEL or phosphorus loading cap, would be greater than 1.4% of the median adjusted gross household income of the service area based on the latest information compiled by the Utah State Tax Commission, after inclusion of grants, loans, or other funding made available by the Utah Water Quality Board or other sources. The Director will consider other demonstrations of economic hardship on a case-by-case basis.

  c. If the owner of a discharging treatment works can demonstrate that the TBPEL or phosphorus loading cap are clearly unnecessary to protect waters downstream from the point of discharge, no TBPEL or phosphorus loading cap will be applied.

  d. If the owner of the discharging treatment works can demonstrate that a commensurate phosphorus reduction can be achieved in receiving waters using innovative alternative approaches such as water quality trading, seasonal offsets, effluent reuse, or land application.

  e. Where the owner of a non-lagoon discharging treatment works demonstrates due diligence toward construction of a treatment facility designed to meet the TBPEL, the compliance date shall be no later than January 1, 2025.

  2. All variances to TBPEL and phosphorus loading caps shall be revisited no more frequently than every five years, or when a substantive change in facility operations or a substantive facility upgrade occurs, to determine if the rationale used to justify the conditions in Subsection R317-1-3.3.C remains applicable.

  3. For treatment works required to implement TBPEL or a phosphorus loading cap, the demonstration under Subsection R317-1-3.3.C must be made by January 1, 2018. Unless this demonstration is made, the owner of the discharging treatment works must proceed to implement the TBPEL or phosphorus loading cap, as applicable, in accordance with, respectively, Subsections R317-1-3.3.A and R317-1-3.3.B.

  D. Facility Optimization to Remove Total Inorganic Nitrogen

  1. If the owner of a discharging treatment works agrees to optimize the owner's facility, either through operational changes, a capital construction project, or both, to reduce effluent total inorganic nitrogen concentrations to a level agreeable to the Director, a waiver of up to ten years from meeting either water quality-based effluent limits or technology-based effluent limits for total inorganic nitrogen will be granted. This includes meeting any total inorganic nitrogen limit that may result from a TMDL or other water quality study that is specific to the receiving water of the treatment works.

  2. The waiver period under this section would begin upon implementation of the optimization improvements or another date agreed to by the owner of the treatment works and the Director.

  3. The elements of the waiver under this section will be identified in a compliance agreement that will be incorporated into the facility's UPDES permit.

  4. The waiver identified under this section must be granted before January 1, 2020. Thereafter, no such waiver will be considered or granted.

  E. Monitoring

  1. All discharging treatment works are required to implement, at a minimum, monthly monitoring of:

  a. influent for total phosphorus (as P) and total Kjeldahl nitrogen (as N) concentrations; and

  b. effluent for total phosphorus and orthophosphate (as P), and ammonia, nitrate-nitrite, and total Kjeldahl nitrogen (as N).

  2. The Director may authorize a variance to the monitoring requirements identified in Subsection R317-1-3.3.D.1.

  3. All monitoring under Subsection R317-1-3.3.D shall be based on 24-hour composite samples by use of an automatic sampler or by combining a minimum of four grab samples collected at least two hours apart within a 24-hour period.

  4. These monitoring requirements shall be self-implementing beginning July 1, 2015.

  3.4 Pollutants In Diverted Water Returned To Stream.

  A user of surface water diverted from waters of the State will not be required to remove any pollutants which such user has not added before returning the diverted flow to the original watercourse, provided there is no increase in concentration of pollutants in the diverted water. Should the pollutant constituent concentration of the intake surface waters to a facility exceed the effluent limitations for such facility under a federal National Pollutant Discharge Elimination System permit or a permit issued pursuant to State authority, then the effluent limitations shall become equal to the constituent concentrations in the intake surface waters of such facility. This section does not apply to irrigation return flow.