No industrial user shall introduce, or cause to be introduced into the POTW, any pollutant or wastewater which causes pass- through or interference. These general prohibitions apply to all industrial users of the POTW whether or not they are subject to categorical pretreatment standards or any other national, State, or local pretreatment standards or requirements. Furthermore, no industrial user may contribute the following substances to the POTW:
A. Fire Or Explosion Hazard: Pollutants which create a fire or explosion hazard in the Municipal wastewater collection system and POTW, including, but not limited to, wastestreams with a closed cup flashpoint of less than one hundred forty degrees Fahrenheit (140°F) (60°C) using the test methods specified in 40 CFR 261.21.
B. Corrosive Properties: Any waters or wastes having a pH lower than 5.5, or higher than 9.5, or having any other corrosive property capable of causing damage or hazard to structures, equipment, and personnel of the wastewater works.
C. Solid Or Viscous Substances: Solids or viscous substances in quantities, or of such size capable of causing obstruction to the flow in the sewers, or other interference with the proper operation of the wastewater facilities such as, but not limited to, ashes, bones, cinders, sand, mud, straw, shavings, metal, glass, rags, feathers, tar, plastics, wood, unground garbage, whole blood, paunch manure, hair and flesh, entrails, asphalt residues from refining or processing of fuel or lubricating oil and paper dishes, cups, milk containers, etc., either whole or ground by garbage grinders, or other substances which may solidify or become viscous at temperatures between thirty two degrees Fahrenheit (32°F) and one hundred fifty degrees Fahrenheit (150°F) (65°C).
D. Pollutants: Any pollutant, including oxygen demanding pollutants, released in a discharge at a flow rate or pollutant concentration which will cause interference or pass- through at the Mason City POTW or which constitutes a "slug" load as defined in this chapter.
E. Temperature: Any wastewater having a temperature greater than one hundred fifty degrees Fahrenheit (150°F) upon entering the collection system, or which will inhibit biological activity in the treatment plant resulting in interference, but in no case shall wastewater which causes temperature at the introduction into the treatment plant to exceed one hundred four degrees Fahrenheit (104°F).
F. Petroleum Products: Petroleum oil, nonbiodegradable cutting oil or products of mineral oil in origin, in amounts that will cause interference or pass-through.
G. Toxic Substances: Any pollutants which result in the presence of toxic gases, vapors or fumes within the POTW in a quantity that may cause acute worker health and safety problems.
H. Imported Material: Any trucked or hauled pollutants, except at discharge points designated by the City. (Ord. 94-14, 7-5-1994)
I. Discharge Limits: Discharge of wastewater from underground storage tank site cleanups or any wastewater containing petroleum products shall not exceed the following limits prior to discharge to the POTW:
Benzene | 0.050 mg/L |
BETX | 0.750 mg/L |
(Ord. 97-3, 1-21-1997; amd. 2017 Code)
J. Ground Garbage: Any garbage that has not been properly shredded (see definition of "properly shredded garbage" in section 6-2-2 of this chapter). Garbage grinders may be connected to sanitary sewers from homes, hotels, institutions, restaurants, hospitals, catering establishments or similar places where garbage originates from the preparation of food in kitchens for the purpose of consumption on the premises or when served by caterers.
K. Heavy Metals: Any waters or wastes containing iron, arsenic, cadmium, chromium, copper, lead, nickel, mercury, and zinc, and similar objectionable or toxic substances in concentration or at flow rates that would cause interference. (Ord. 94-14, 7-5-1994)
L. Odoriferous Substances: Any waters or wastes containing odor producing substances exceeding limits or causing public nuisance which may be addressed by the Wastewater Superintendent and other regulatory agencies. (Ord. 94-14, 7-5-1994; amd. 2017 Code)
M. Deleterious Substances: Any water or wastes which, by interaction with other water or wastes in the public sewer system, release obnoxious gases, form suspended solids which interfere with the collection system (such as, but not limited to, fuller's earth, lime slurries and lime residues), or of dissolved solids (such as, but not limited to, sodium chloride and sodium sulfate), which exceed or create a condition deleterious to structures and treatment processes.
N. Dyes: Any wastewater which imparts color which cannot be removed by the treatment process, such as, but not limited to, dye wastes and vegetable tanning solutions, which consequently imparts color to the treatment plant's effluent thereby violating the City's NPDES permit. Color (in combination with turbidity) shall not cause the treatment plant effluent to reduce the depth of the compensation point for photosynthetic activity by more than ten percent (10%) from the seasonably established norm for aquatic life.
O. Radioactive Wastes: Any radioactive wastes unless they comply with the Atomic Energy Commission Act of 1954 (68 stat. 919 as amended and part 20, subpart D - Waste Disposal, section 20.303 of the regulations issued by the Atomic Energy Commission, or amendments thereto).
P. Runoff: Stormwater, surface water, groundwater, artesian well water, roof runoff, subsurface drainage, swimming pool drainage, condensate, deionized water, noncontact cooling water and unpolluted industrial wastewater, unless specifically authorized by the Superintendent.
Q. Residues: Any sludges, screenings or other residues from the pretreatment of industrial wastes.
R. Toxicity Test: Any wastewater causing the treatment plant's effluent to fail a toxicity test.
S. Foaming Substances: Any wastes containing detergents, surface active agents, or other substances which may cause excessive foaming in the POTW. (Ord. 94-14, 7-5-1994)
T. Animal Fats: Any discharge of fats, oils or greases of animal or vegetable origin is limited to two hundred milligrams per liter (200 mg/l), or categorical standards if more stringent. (Ord. 94-14, 7-5-1994; amd. 2017 Code)
U. Pretreatment Requirements: Any waters which do not meet the applicable requirements or National Pretreatment Standards (40 CFR 403.8(f)(1)(ii)).
V. Discharge: Wastes prohibited by this section shall not be processed or stored in such a manner that they could be discharged to the POTW. All floor drains located in process or materials storage areas must discharge to the industrial user's pretreatment facility before connecting with the POTW. (Ord. 94-14, 7-5-1994)
W. Local Limits:
1. Headworks Limits; Average Mass: The average composite loading of all industrial users contributing the following specific pollutants to the POTW shall not exceed the allowable total pounds. The Superintendent will distribute the allowable industrial load through permits to significant industrial users.
TABLE A
Pollutant | Total Of All Sources (30 Day Average Allowable In Pounds/Day) | Industrial (30 Day Average Allowable In Pounds/Day) |
BOD | 28,235 | 20,638 |
TSS | 33,814 | 24,817 |
NH3 | 3,348 | 2,457 |
TABLE B
Pollutant | Maximum Allowable Headworks Loading Pounds/Day | Maximum Allowable Industrial Loading Pounds/Day |
Total | Industrial |
Pollutant | Maximum Allowable Headworks Loading Pounds/Day | Maximum Allowable Industrial Loading Pounds/Day |
Total | Industrial | |
Arsenic-T | 0.365 | 0.337 |
Cadmium-T | 0.278 | 0.271 |
Chromium-T | 6.020 | 5.913 |
Chromium VI | 6.020 | 4.392 |
Copper-T | 10.958 | 8.895 |
Cyanide-T | 2.066 | 2.027 |
Lead-T | 0.918 | 0.764 |
Mercury-T | 0.208 | 0.201 |
Molybdenum-T | 0.329 | 0.216 |
Nickel-T | 2.192 | 2.007 |
Selenium-T | 0.438 | 0.383 |
Silver-T | 0.054 | 0.040 |
Zinc-T | 20.805 | 18.175 |
2. Discharge Concentration Or Mass Limits And Review Criteria:
a. Concentration Or Limits: Discharge concentration or mass limits and review criteria shall be as follows:
(1) The discharge into the POTW of any materials, water or wastewater having a pollutant level greater than the limits in tables A, B, C or D of this subsection W or containing pollutants not listed in this subsection W shall be subject to the review and approval of the POTW Superintendent.
(2) After review of the proposed discharges, the Superintendent may:
(A) Reject the water or wastewater.
(B) Require pretreatment to an acceptable pollutant level for discharge to the POTW.
(C) Require control of the quantities and rates of discharge of the water or wastewater.
(D) Require payment to cover the added cost of handling and treatment of water or wastewater or any combination thereof.
(E) Reduce the maximum or average mass loading of present and prospective industrial users on any reasonable prorated basis to meet headworks loading limits at the WRF.
(F) Require the user to obtain a wastewater discharge permit and be subject to any of the rules and regulations contained therein.
(G) Require the user to meet local limits when local limits are more restrictive than National Categorical Pretreatment Standards.
b. Wastewater With Pollutant Concentrations: Users discharging wastewater with pollutant concentrations that are greater than the following shall be considered industrial users for purposes of sewer charges and may be regulated or permitted by the POTW Superintendent as appropriate:
TABLE C
Pollutant | Daily Maximum (mg/l) |
BOD | 300 |
TSS | 250 |
Oil and grease-T | 200 |
TKN | 30 |
NH3-N | 15 |
Having an unusual concentration of flow constituting a slug load | |
c. Pollutant Limits: New industrial users shall contact the POTW if any of the following limits are exceeded to assess if a permit is required:
TABLE D
Pollutant | Monthly Limit (mg/l) |
Pollutant | Monthly Limit (mg/l) |
Arsenic-T | 0.04 |
Cadmium-T | 0.26 |
Chromium-T | 1.71 |
Chromium VI | 1.28 |
Copper-T | 2.07 |
Cyanide-T | 0.65 |
Lead-T | 0.43 |
Mercury-T | 0.003 |
Molybdenum-T | 0.025 |
Nickel-T | 2.38 |
Selenium-T | 0.045 |
Silver-T | 0.24 |
Zinc-T | 1.48 |
(Ord. 97-3, 1-21-1997; amd. 2017 Code)