(A) The Superintendent is authorized to establish local limits pursuant to 40 C.F.R. § 403.5(c).
(B) The City of Guthrie is authorized to establish local limits pursuant to 40 C.F.R. § 403.5(c). The following limitations are established for characteristics of any wastewaters to be discharged into the municipal sewer system subject to any compliance schedule as established in the industrial user permit. All significant industrial users must comply with the applicable limitations where they are more stringent than applicable state and/or federal regulations. These local limits are established to protect against pass through and interference. Additional and/or more stringent limits may be necessary if any pass through and/or interference are detected. Best management practices may be developed, or required by industry, to implement the prohibitions listed in 40 C.F.R. § 403.5(a)(1) or within this chapter. Such BMPs shall be considered local limits and pretreatment standards as determined by the city.
Parameter | Maximum Daily Concentration |
Parameter | Maximum Daily Concentration |
pH | 5.5 to 9 |
Arsenic, total | 0.12 mg/l |
Cadmium, total | 0.01 mg/l |
Chromium, hexavalent | 0.27 mg/l |
Chromium, total | 1.71 mg/l |
Copper, total | 0.30 mg/l |
Cyanide, Amenable | 0.10 mg/l |
Lead, total | 0.06 mg/l |
Mercury, total | 0.0004 mg/l |
Nickel, total | 0.62 mg/l |
Selenium, total | 0.07 mg/l |
Silver | 0.015 mg/l |
Zinc | 1.97 mg/l |
(C) The Superintendent may develop best management practices (BMPs), by ordinance or in individual wastewater discharge permits, to implement local limits and the requirements of § 51.15.
(D) (1) Any water or wastes which have characteristics based on a 24-hour composite sample, grab or a shorter period composite sample, if more representative, that exceed the following normal maximum domestic wastewater pollutant concentrations:
Parameter | Maximum Allowable Concentration Without Surcharges |
Ammonia-nitrogen | 25 mg/l |
BOD | 300 mg/l |
COD | 900 mg/l |
Oil and grease, total | 100 mg/l |
Phosphorus, total | 10 mg/l |
TSS | 300 mg/l |
(2) Any person discharging wastewater exceeding the maximum allowable concentration as noted above, will be subject to a surcharge fee for each pound loading over and above the set limit. Any other amenable constituents requiring the addition of specific chemicals for proper treatment will also be subject to surcharge as noted on the industrial user permit. Exceedance of the effluent limits specified above shall not be deemed to constitute a violation of a permit condition or this section if the appropriated surcharge fee is paid and the discharge does not cause interference or pass through the POTW.
(E) Surcharge rates. The following surcharge rates shall apply for each pound of loading in excess of the concentrations above:
Parameter | Rate |
BOD, 5-day | $0.73 per pound |
COD | $0.73 per pound |
Ammonia-nitrogen (NH3-N) | $0.00 per pound |
Oil and grease, total | $0.25 per pound |
Phosphorus, total | $0.00 per pound |
Total suspended solids (TSS) | $0.59 per pound |
(F) Method of billing surcharge fees.
(1) The excessive strength surcharge fee shall be based on the following formula, with the total to be applied to the monthly bill of affected users:
(a) Surcharge fee ($/month) = [A(G-300) + B(H-300) + C(I-25) + D(J-100) + E(K-10)] x 0.00834 x Q; or
(b) Surcharge fee ($/month) = [F(L-900) + B(H-300) + C(I-25) + D(J-100) + E(K-10)] x 0.00834 x Q.
(2) The formula giving the larger surcharge fee will be used each month.
(3) Formula components are as follows:
(a) A = surcharge rate for BOD, in $/pound;
(b) B = surcharge rate for TSS, in $/pound;
(c) C = surcharge rate for NH3-N, in $/pound;
(d) D = surcharge rate for oil and grease (total), in $/pound;
(e) E = surcharge rate for total phosphorus, in $/pound;
(f) F = surcharge rate for COD, in $/pound;
(g) G = user's average BOD concentration, in mg/l;
(h) H = user's average TSS concentration, in mg/l;
(i) I = user's average NH3-N concentration, in mg/l;
(j) J = user's average oil and grease (total) concentration, in mg/l;
(k) K = user's average phosphorus concentration, in mg/l;
(l) L = user's average COD concentration, in mg/l; and
(m) Q = user's monthly flow to sewage works, per 1,000 gallons.
(Ord. 2015-9, passed 11-10-2015; Ord. 2020-3, passed 3-12-2020; Ord. 2021-1, passed 2-9-2021)