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Industrial Pretreatment Westbrook-Gorham

Industries in the Westbrook-Gorham IPT program are connected to the City of Westbrook’s or the Town of Gorham’s sewer collection system and the wastewater they generate is treated at the Westbrook-Gorham Regional Wastewater Treatment Facility.  In addition, the Little Falls area in the Town of Windham, as well as a small section of the City of Portland drains to the Westbrook collection system.  Any industries located in these areas are permitted under the Westbrook-Gorham Industrial Pretreatment Program. For more information on the inter-municipal region go here.  The Westbrook-Gorham Industrial Pretreatment Program is funded by a monthly fee paid by permitted industrial customers. Please explore the following links for more information on the Westbrook IPT program:


PWD IPT staff issue permits to industrial customers of the wastewater system in Westbrook, Gorham and part of Windham.  As of March 2022 there were 17 permitted industries in the program. Industries are permitted when they meet one or more of the following conditions:

  • Discharge an average of 25,000 gallons or more of process wastewater per day
  • Discharge a process waste stream making up 5% or more of the average dry weather flow (or load) to the treatment plant
  • Subject to Federal Categorical Standards
  • Have reasonable potential to impact or affect the treatment plant or collection system, or reasonable potential to violate a pretreatment standard

Industrial customers are issued one of two different types of permit based on the types of activities they are performing.  Permit types include:

Full Permit

  • Renewed every three years
  • Conduct self-monitoring on a regular basis
  • Submit discharge reports on a routine basis (monthly, quarterly, or semi-annually depending on wastewater characteristics)

Best Management Practice (BMP) Permit

  • Renewed every three years
  • Not required to conduct self-monitoring
  • Submit BMP certifications semi-annually



Permitted industries (as of March 2022):




D&G Machine BMP

Helical Solutions BMP


Lone Pine Brewing Company 

Mast Landing Brewing Company

Maine Correctional Center

MEGA Industries BMP

Maine Medical Center Laundry


Schlotterbeck and Foss

Sebago Brewing

Sigco BMP


Southern Maine Specialties


Local company, Sigco, earns excellence in pretreatment award.  

Westbrook Permit Application

Gorham Windham Permit Application

Westbrook Limits
Parameter Discharge Limit, Daily Maximum
Biochemical Oxygen Demand (BOD) *
Total Suspended Solids (TSS) *
Arsenic 0.094 mg/L
Cadmium 0.0132 mg/L
Chromium 2.35 mg/L
Copper 0.69 mg/L
Cyanide 0.52 mg/L
Lead 0.33 mg/L
Mercury 0.0037 mg/L
Nickel 0.20 mg/L
Silver 0.14 mg/L
Zinc 1.41 mg/L
Total Oil and Grease 100 mg/L
Non-Polar Oil and Grease (Hydrocarbon) Not Applicable


More information

Westbrook Ordinance (Chapter 260 apply to sewers and industrial pretreatment)

PWD Sewer User Rules

Enforcement Response Plan effective 2-15-21 

Federal categorical regulations

Dental amalgam rule



Contact Industrial Pretreatment

pH must be greater than 5.0 standard units and have a caustic alkalinity less than 1000 mg/L. Any pH result above 10.3 standard units must be accompanied by a result for caustic (hydroxide) alkalinity from the same sample. pH above 12.5 standard units is prohibited and considered hazardous waste.

*Industrial Users permitted in the Industrial Pretreatment Program and discharging effluent which exceeds a de minimis level of BOD and/or TSS are individually allocated a pounds per day limit for these parameters.  The de minimis levels are as follows: Westbrook: 250 mg/L and/or 375 lbs/day for BOD and 300 mg/L and or 425 lbs/day for TSS.

The Control Authority (PWD) reserves the right to permit users based on their potential to discharge high strength BOD and/or TSS waste.  Industrial Users who are permitted for BOD and TSS must report a certified discharge flow number with each monitoring event.

NOTE: the City of Westbrook may have adopted other prohibitions and limitations in their respective rules or ordinances.  Please refer to the City’s ordinances for more information.