(a) 
General prohibitions. No 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 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.
(b) 
Specific prohibitions. No user shall introduce or cause to be introduced into the POTW the following pollutants, substances, or wastewater:
(1) 
Pollutants which create a fire or explosive hazard in the POTW, including, but not limited to, waste streams with a closed-cup flashpoint of less than 140° F. (60° C) using the test methods specified in 40 CFR 261.21.
(2) 
Wastewater having a pH of less than 5.0 or more than 11.5, or otherwise causing corrosive structural damage to the POTW or equipment.
(3) 
Solid or viscous substances in amounts which will cause obstruction of the flow in the POTW resulting in interference.
(4) 
Pollutants, including oxygen-demanding pollutants (BOD, etc.), released in a discharge at a flow rate and/or pollutant concentration which, either singly or by interaction with other pollutants, will cause interference with the POTW.
(5) 
Wastewater having a temperature greater than 104° F. (40° C). or which will inhibit biological activity in the treatment plant resulting in interference, but in no case wastewater which causes the temperature at the introduction into the treatment plant to exceed 140° F. (40° C).
(6) 
Petroleum oil, nonbiodegradable cutting oil, or products of mineral oil origin in amounts that will cause interference or pass-through.
(7) 
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.
(8) 
Trucked or hauled pollutants, except at discharge points designated by the Director of Wastewater or his/her designee, in accordance with Section 71-14 chapter.
(9) 
Noxious or malodorous liquids, gases, solids, or other wastewater which, either singly or by interaction with other wastes, is sufficient to create a public nuisance or a hazard to life, or to prevent entry into the sewers for maintenance or repair.
(10) 
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 MEPDES permit.
(11) 
Wastewater containing any radioactive wastes or isotopes except in compliance with applicable state or federal regulations.
(12) 
Stormwater, surface water, groundwater, artesian well water, roof runoff, subsurface drainage, swimming pool drainage, condensate, de-ionized water, noncontact cooling water, and unpolluted wastewater, unless specifically authorized by the Director of Wastewater or his/her designee.
(13) 
Sludges, screenings, or other residues from the pretreatment of industrial wastes or other package wastewater treatment plants.
(14) 
Medical wastes, except as specifically authorized by the Director of Wastewater or his/her designee in an individual wastewater discharge permit.
(15) 
Wastewater causing, alone or in conjunction with other sources, the treatment plant's effluent to fail toxicity test.
(16) 
Detergents, surface-active agents or other substances that might cause excessive foaming in the POTW.
(17) 
Fats, oils, or greases of animal or vegetable origin in concentrations greater than 200 mg/l.
(18) 
Wastewater causing two readings on an explosion hazard meter at the point of discharge into the POTW, or at any point in the POTW, of more than 10% or any single reading over the lower explosive limit of the meter.
(c) 
Pollutants, substances, or wastewater prohibited by this section shall not be processed or stored in such a manner that they could be discharged to the POTW.
Users must comply with the categorical pretreatment standards found at 40 CFR Chapter I, Subchapter N, Parts 405 through 471.
(1) 
Where a categorical pretreatment standard is expressed only in terms of either the mass or the concentration of a pollutant in wastewater, the Director of Wastewater or his/her designee, may impose equivalent concentration or mass limits in accordance with Subsections (5) and (6).
(2) 
When the limits in a categorical pretreatment standard are expressed only in terms of mass of pollutant per unit of production, the Director of Wastewater or his/her designee may convert the limits to equivalent limitations expressed either as mass of pollutant discharged per day or effluent concentration for purposes of calculating effluent limitations applicable to individual industrial users.
(3) 
When wastewater subject to a categorical pretreatment standard is mixed with wastewater not regulated by the same standard, the Director of Wastewater or his/her designee shall impose an alternate limit in accordance with 40 CFR 403.6(e).
(4) 
A CIU may obtain a net/gross adjustment to a categorical pretreatment standard in accordance with the following paragraphs of this section.
a. 
Categorical pretreatment standards may be adjusted to reflect the presence of pollutants in the industrial user's intake water in accordance with this section. Any industrial user wishing to obtain credit for intake pollutants must make application to the City. Upon request of the industrial user, the applicable standard will be calculated on a net basis (i.e., adjusted to reflect credit for pollutants in the intake water) if the requirements of Subsection (4)b of this section are met.
b. 
Criteria.
1. 
Either the applicable categorical pretreatment standards contained in 40 CFR Subchapter N specifically provide that they shall be applied on a net basis; or the industrial user demonstrates that the control system it proposes or uses to meet applicable categorical pretreatment standards would, if properly installed and operated, meet the Standards in the absence of pollutants in the intake waters.
2. 
Credit for generic pollutants, such as biochemical oxygen demand (BOD), total suspended solids (TSS), and oil and grease, should not be granted unless the industrial user demonstrates that the constituents of the generic measure in the user's effluent are substantially similar to the constituents of the generic measure in the intake water or unless appropriate additional limits are placed on process water pollutants either at the outfall or elsewhere.
3. 
Credit shall be granted only to the extent necessary to meet the applicable categorical pretreatment standard(s), up to a maximum value equal to the influent value. Additional monitoring may be necessary to determine eligibility for credits and compliance with standard(s) adjusted under this section.
4. 
Credit shall be granted only if the user demonstrates that the intake water is drawn from the same body of water as that into which the POTW discharges. The City may waive this requirement if it finds that no environmental degradation will result.
(5) 
When a categorical pretreatment standard is expressed only in terms of pollutant concentrations, an industrial user may request that the City of Biddeford, Maine, convert the limits to equivalent mass limits. The determination to convert concentration limits to mass limits is within the discretion of the Director of Wastewater or his/her designee. The City of Biddeford, Maine, may establish equivalent mass limits only if the industrial user meets all the conditions set forth in Subsections (5)a1 through (5)a5 Below.
a. 
To be eligible for equivalent mass limits, the industrial user must:
1. 
Employ, or demonstrate that it will employ, water conservation methods and technologies that substantially reduce water use during the term of its individual wastewater discharge permit;
2. 
Currently use control and treatment technologies adequate to achieve compliance with the applicable categorical pretreatment standard and not have used dilution as a substitute for treatment;
3. 
Provide sufficient information to establish the facility's actual average daily flow rate for all waste streams, based on data from a continuous effluent flow monitoring device, as well as the facility's long-term average production rate. Both the actual average daily flow rate and the long-term average production rate must be representative of current operating conditions;
4. 
Not have daily flow rates, production levels, or pollutant levels that vary so significantly that equivalent mass limits are not appropriate to control the discharge; and
5. 
Have consistently complied with all applicable categorical pretreatment standards during the period prior to the industrial user's request for equivalent mass limits.
b. 
An industrial user subject to equivalent mass limits must:
1. 
Maintain and effectively operate control and treatment technologies adequate to achieve compliance with the equivalent mass limits;
2. 
Continue to record the facility's flow rates through the use of a continuous effluent flow-monitoring device;
3. 
Continue to record the facility's production rates and notify the Director of Wastewater or his/her designee whenever production rates are expected to vary by more than 20% from its baseline production rates determined in Subsection (5)a3 of this section. Upon notification of a revised production rate, the Director of Wastewater or his/her designee will reassess the equivalent mass limit and revise the limit as necessary to reflect changed conditions at the facility; and
4. 
Continue to employ the same or comparable water conservation methods and technologies as those implemented pursuant to Subsection (5)a1 of this section so long as it discharges under an equivalent mass limit.
c. 
When developing equivalent mass limits, the Director of Wastewater or his/her designee:
1. 
Will calculate the equivalent mass limit by multiplying the actual average daily flow rate of the regulated process(es) of the industrial user by the concentration-based daily maximum and monthly average standard for the applicable categorical pretreatment standard and the appropriate unit conversion factor;
2. 
Upon notification of a revised production rate, will reassess the equivalent mass limit and recalculate the limit as necessary to reflect changed conditions at the facility; and
3. 
May retain the same equivalent mass limit in subsequent individual wastewater discharger permit terms if the industrial user's actual average daily flow rate was reduced solely as a result of the implementation of water conservation methods and technologies, and the actual average daily flow rates used in the original calculation of the equivalent mass limit were not based on the use of dilution as a substitute for treatment pursuant to Section 71-10. The industrial user must also be in compliance with Section 71-70 regarding the prohibition of bypass.
(6) 
The Director of Wastewater or his/her designee may convert the mass limits of the categorical pretreatment standards of 40 CFR Parts 414, 419, and 455 to concentration limits for purposes of calculating limitations applicable to individual industrial users. The conversion is at the discretion of the Director of Wastewater or his/her designee.
(7) 
Once included in its permit, the industrial user must comply with the equivalent limitations developed in this Section 71-6 in lieu of the promulgated categorical standards from which the equivalent limitations were derived.
(8) 
Many categorical pretreatment standards specify one limit for calculating maximum daily discharge limitations and a second limit for calculating maximum monthly average, or four-day average, limitations. Where such standards are being applied, the same production or flow figure shall be used in calculating both the average and the maximum equivalent limitation.
(9) 
Any industrial user operating under a permit incorporating equivalent mass or concentration limits calculated from a production-based standard shall notify the Director of Wastewater or his/her designee within two business days after the user has a reasonable basis to know that the production level will significantly change within the next calendar month. Any user not notifying the Director of Wastewater or his/her designee of such anticipated change will be required to meet the mass or concentration limits in its permit that were based on the original estimate of the long-term average production rate.
Users must comply with State of Maine pretreatment standards codified as state law.
(a) 
The Director of Wastewater or his/her designee is authorized to establish local limits pursuant to 40 CFR 403.5(c).
(b) 
Local limits established.
(1) 
The following pollutant limits are established to protect against pass-through and interference. No person shall discharge wastewater containing in excess of the following local limits (daily maximum mg/l) unless otherwise stated:
[Amended 10-5-2010 by Ord. No. 2010.101; 5-16-2023 by Ord. No. 2023.37]
Substance
Limit
pH (lower than 5.0 never, higher than 11.45 for five minutes only)
5.0 to 11.5 s.u
Ammonia
593 mg/l
Arsenic
0.30 mg/l
BOD5
3,756 mg/l
Cadmium
0.20 mg/l
Chromium (total)
6.00 mg/l
Copper
2.00 mg/l
Cyanide
0.70 mg/l
Lead
1.00 mg/l
Mercury
1,270* ng/l
Molybdenum
1.66 mg/l
Nickel
5.20mg/l
Oil and/or grease
200 mg/l
Selenium
1.82 mg/l
Silver
2.00 mg/l
Total suspended solids
4,000 mg/l
Zinc
2.00 mg/l
TTO (total toxic organics)
4.00 mg/l
NOTE:
*
Clean mercury is in ng/l and is set by State of Maine collected data. This limit is suggestive and is not subject to violation, however, corrective pollution control measures may be administered if the clean mercury is above suggestive limit.
(2) 
The above limits 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 Director of Wastewater or his/her designee may impose mass limitations in addition to the concentration-based limitations above.
(c) 
The Director of Wastewater or his/her designee may develop best management practices (BMPs) by ordinance or in individual wastewater discharge permits to implement local limits and the requirements of Section 71-5.
The City reserves the right to establish, by ordinance or in individual wastewater discharge permits, more stringent standards or requirements on discharges to the POTW consistent with the purpose of this chapter.
No user shall ever increase the use of process water or in any way attempt to dilute a discharge as a partial or complete substitute for adequate treatment to achieve compliance with a discharge limitation unless expressly authorized by an applicable pretreatment standard or requirement. The Director of Wastewater or his/her designee may impose mass limitations on users who are using dilution to meet applicable pretreatment standards or requirements, or in other cases when the imposition of mass limitations is appropriate.