(A) The Superintendent is authorized to establish local limits pursuant to 40 CFR 403.5(c).
(1) This chapter establishes uniform concentration limits in division (B) below for the pollutants of concern listed in that division. These limits shall apply to all non-residential users discharging to the POTW. The pollutants regulated in division (B) below are those for which composite sampling is inappropriate; or those for which a user-specific pollutant allocation is impractical or otherwise inappropriate.
(2) This chapter establishes domestic background concentrations in division (C) below for the pollutants listed in that division. These domestic background concentration values shall constitute the enforceable local limit for pollutants not listed in division (B) below and shall apply to all non-residential users; except as provided in divisions (C)(1) through (C)(3) below.
(3) This chapter also establishes maximum allowable industrial loadings (MAILs) in division (D) below for pollutants of concern listed in that division. These MAILs shall be used by the Superintendent to establish user-specific discharge limits for contributing dischargers in accordance with the provisions of divisions (D) through (G) below. Such user-specific discharge limits shall be included in individual wastewater discharge permits for the users to whom they apply.
(B) The following pollutant limits are established to protect the POTW against pass through and interference. No person shall discharge wastewater containing pollutant concentrations in excess of the following instantaneous maximum limits (IMLs) or daily maximum limits (DMLs). The following limits shall apply at the point where the wastewater is discharged to the POTW. The Superintendent may impose either mass limitations or concentration-based limitations contained in the following table.
POLLUTANT | IML | DML |
Oil & grease, non-polar | 57 mg/l | 28 mg/l |
Oil & grease, polar | 265 mg/l | 32 mg/l |
Phenols, total recoverable | 13.2 mg/l | 6.6 mg/l |
(C) The following domestic background concentration values are included for use in the establishment of local limits. The domestic background concentration values listed below shall constitute the enforceable local limit for pollutants not listed in division (B) above and shall apply to all non-residential users with the following exceptions:
(1) Where the Superintendent has established a user-specific discharge limit for a pollutant in an individual wastewater discharge permit in accordance with divisions (D) through (G) below.
(2) Where the Superintendent has not established a user-specific discharge limit for a pollutant; and an alternate compliance criterion value is given below in the table.
(3) Where a non-residential user is regulated through an existing individual or general wastewater discharge permit on the effective date of this chapter and the Superintendent has not modified the existing wastewater discharge permit, or issued a new wastewater discharge permit, to include:
(a) Local limits provided by this division (C); and/or
(b) User-specific local limits in accordance with divisions (D) through (G) below.
(4) Should the average monthly loading to POTW exceed 80% of the design loading for cBOD5, ammonia nitrogen or total suspended solids, for three consecutive months, the Superintendent will evaluate whether a local limit is necessary for these pollutants and impose these limits on non-residential users.
(5) Local limits established under this division (C) shall apply at the point where the wastewater is discharged to the POTW. All concentrations for metallic substances are for total metal unless indicated otherwise. The Superintendent may impose either mass-based limitations or concentration-based limitations contained in the following table.
POLLUTANT | DOMESTIC BACKGROUND |
POLLUTANT | DOMESTIC BACKGROUND |
Arsenic, Total | 0.0029 mg/l |
Cadmium, Total | 0.0001 mg/l |
Chromium, Total | 0.0011 mg/l |
Copper, Total | 0.1026 mg/l |
Cyanide, Total | 0.0040 mg/l |
Fluoride, Total | 0.5700 mg/l |
Lead, Total | 0.0008 mg/l |
Mercury, Total | 0.0001 mg/l |
Molybdenum, Total | 0.0045 mg/l |
Nickel, Total | 0.0010 mg/l |
Selenium, Total | 0.0001 mg/l |
Silver, Total | 0.0001 mg/l |
Zinc, Total | 0.0786 mg/l |
(D) The following maximum allowable industrial loadings (i.e., MAILs) are established to protect the POTW against pass through and interference. These MAILs shall be used by the Superintendent when user-specific local limits are developed for pollutants not regulated under division (B) above. The following MAILs represent the total combined loading for each pollutant that may be accepted from all non-residential users discharging to the POTW. Any user-specific discharge limits derived from the following MAILs shall apply at the point where the user’s wastewater is discharged to the POTW.
Arsenic, Total | 5.7326 lbs/day |
Cadmium, Total | 0.2993 lbs/day |
Chromium, Total | 63.9337 lbs/day |
Copper, Total | 13.5432 lbs/day |
Cyanide, Total | 0.3591 lbs/day |
Fluoride, Total | Report Value |
Lead, Total | 1.2408 lbs/day |
Mercury, Total | 0.0161 lbs/day |
Molybdenum, Total | Report Value |
Nickel, Total | 50.7305 lbs/day |
Selenium, Total | 5.5826 lbs/day |
Silver, Total | 3.1566 lbs/day |
Zinc, Total | 64.0779 lbs/day |
(E) Non-residential users may file a written request with the Superintendent asking the Superintendent to establish user-specific discharge limitations for any of the pollutants included in divisions (C) or (D) above. The following provisions shall govern any user requests for the establishment of user-specific discharge limitations:
(1) Deviation from the local limits established in division (C) above (i.e., implementation of user-specific pollutant discharge limitations) shall remain under the sole discretion of the Superintendent. The Superintendent shall establish pollutant discharge allocations for existing allocated discharges in accordance with the criteria established in divisions (F) through (G) below. The initial pollutant discharge allocation for an existing allocated discharge shall not be more stringent than the corresponding proposed allocation in the “Local Limits Revision Summary Report” prepared on behalf of the Superintendent in support of this chapter unless the Superintendent demonstrates that a more stringent allocation is technically feasible given the user’s current treatment system and is necessary to prevent pass-through or interference.
(2) Non-residential users filing such a request must justify to the city’s satisfaction that the local limits as included in division (C) above cannot be reasonably achieved through the implementation of BMPs, modification of existing pretreatment equipment, or installation of new pretreatment equipment or facilities.
(F) The Superintendent, at his or her sole discretion, shall grant a pollutant discharge allocation for any pollutant listed in division (D) above on a case-by-case basis to only those non-residential users that discharge a pollutant to the POTW in excess of the domestic background concentration for a pollutant listed in division (C) above.
(1) The Superintendent will use professional judgment to determine the total amount of each pollutant discharge allocation by assigning a portion of the appropriate MAIL to each non-residential user receiving an allocation for each pollutant for which an allocation is granted.
(2) The Superintendent shall consider, but not be limited to, the following factors when performing case-by-case allocation of the MAIL to contributing non-residential users:
(a) The contributing users current loading to the POTW;
(b) The contributing users need for continued loading allocation;
(c) The user’s need for a new or increased allocation;
(d) The user’s ability to apply pretreatment to achieve discharge pollutant levels (i.e., treatability);
(e) Changes to the POTW treatment system that affect the MAIL;
(f) Any other factor that the Superintendent determines is relevant.
(3) Where the Superintendent grants an allocation of the MAIL to a contributing user for one or more pollutants, he or she shall establish corresponding user-specific discharge limitations for such pollutants in accordance with the provisions of divisions (D) through (G) of this section. Such user-specific discharge limits shall be included in individual wastewater discharge permits for the contributing user to whom they apply.
(G) When user-specific pollutant discharge limitations are developed from case-by-case pollutant discharge allocations; the Superintendent shall ensure that:
(1) The total allocation to non-residential users for a specific pollutant does not exceed the maximum allowable industrial loading (i.e., MAIL) for that pollutant listed in division (D) above; or the most current calculated MAIL available to the Superintendent. Moreover; in order to prevent over-allocation of the MAIL for a specific pollutant, the Superintendent will reserve a portion of the current MAIL that will not be allocated to non-residential users in order to ensure that a sufficient portion of the MAIL is reserved for non-contributing users that discharge the pollutant of concern at or below the domestic background levels listed in division (C) above.
(2) Non-residential users receiving an allocation of the MAIL for one or more pollutants of concern will have user-specific pollutant discharge limitations included in an individual wastewater discharge permit.
(3) Non-residential users not receiving an allocation of the MAIL will be required to discharge the pollutant of concern at or below the domestic background concentration listed in division (C) above, or as determined by the Superintendent.
(4) Non-residential users already discharging below domestic background levels listed in division (C) must maintain appropriate treatment to ensure that the level of pollutant in their discharge does not increase. In such cases, the Superintendent shall establish an appropriate user-specific pollutant discharge limitation below the domestic background level with which such dischargers must comply.
(H) Best management practices. The Superintendent may develop best management practices (BMPs), by ordinance or in individual or general wastewater discharge permits, to implement local limits established in accordance with divisions (A) through (G) above and the requirements of § 55.016. Such BMPs shall be considered pretreatment standards and be enforceable as pretreatment standards in accordance with 40 CFR 403.5(c)(4).
(Ord. 6619, passed 1-28-13)