Industrial Pretreatment

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The City of Carrollton regulates wastewater from businesses to protect the sanitary sewer system and local waterways. This program, known as the Industrial Pretreatment Program (IPP), helps businesses meet federal, state, and local environmental requirements.

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Environmental Survey

Determine whether a new or existing business must complete the required environmental survey.

Complete the Environmental Survey

Wastewater Discharge Permits

Find out whether a business needs a permit before discharging process wastewater into the sanitary sewer.

Apply for a Wastewater Discharge Permit

Who This Applies To

Businesses that discharge wastewater beyond standard restroom use
Businesses that use chemicals, oils, or industrial materials
Businesses that manufacture, process, clean, or repair products
Facilities such as food production, auto repair, laboratories, and similar operations

What the Program Does

Reviews businesses through Environmental Surveys
Issues wastewater discharge permits
Conducts inspections and wastewater sampling
Enforces environmental regulations
Provides guidance to help businesses stay compliant

Protecting Carrollton’s Water

The City works with businesses to maintain compliance and reduce environmental impact. Education and collaboration help businesses meet requirements while supporting a safe and sustainable community.

Businesses that consistently meet requirements may be recognized through the Environmental Leadership Awards.

Additional Requirements

Wastewater Surcharges

The City of Carrollton has the ability to apply a wastewater surcharge to users' water bills to recover increased treatment costs when wastewater strength exceeds normal levels.

Businesses that participate in City sampling may be evaluated for these surcharge parameters:

Five day biochemical oxygen demand (BOD) greater than 250 mg/l
Total suspended solids (TSS) greater than 250 mg/l
Chemical oxygen demand (COD) greater than 625 mg/l

Surcharge Formula

The standard surcharge formula is:

Surcharge = [Q] [a (BOD - x) + b (TSS - y)] [8.34] [c]

If the chemical oxygen demand concentration is 2.5 times or more than the biochemical oxygen demand concentration, the Designated City Official (DCO) may use the COD category instead of the BOD category. In that case, the formula is:

Surcharge = [Q] [a (COD - z) + b (TSS - y)] [8.34] [c]

Definitions used in the wastewater surcharge formula
Term	Definition
Q	Wastewater flow in million gallons per month
8.34	Weight in pounds of one gallon of water, used to convert mg/l to pounds per million gallons of water
x	BOD level in milligrams per liter above which a surcharge is assessed
y	TSS level in milligrams per liter above which a surcharge is assessed
z	COD level in milligrams per liter above which a surcharge is assessed
a	Unit cost in dollars of treatment per pound of BOD or COD
b	Unit cost in dollars of treatment per pound of TSS
c	Administrative overhead recovery factor in dollars
BOD	Measured amount of biochemical oxygen demand in mg/l
COD	Measured amount of chemical oxygen demand in mg/l
TSS	Measured amount of total suspended solids in mg/l

How Concentrations Are Applied

BOD, COD, and TSS values used in the surcharge calculation are based on the average concentrations determined by testing procedures defined in City code using samples collected or accepted by the Director of Code Operations.

If the average concentration for BOD, COD, or TSS is less than the applicable threshold value of x, y, or z, that term is removed from the surcharge calculation.

Dental Amalgam Requirements

Dental offices in the City of Carrollton must complete a One-Time Compliance Form to meet the Environmental Protection Agency (EPA) Dental Rule.

Dental offices are a primary source of mercury in wastewater because amalgam fillings contain mercury. Amalgam separators help prevent mercury from entering the sewer system.

What to Do

Complete the One-Time Compliance Form
Submit the form with an original signature

Deliver or mail the completed form to:

1945 E Jackson Rd.
Carrollton, TX 75006

Download the One-Time Compliance Form

Learn more about the EPA Dental Rule

City of Carrollton
Environmental Services
1945 E. Jackson Rd.
Carrollton, TX 75006
972-466-3060
Email Pretreatment Program Coordinators

Hours of Operation

Monday-Thursday: 7:30 a.m.-5:30 p.m.

Friday: 7:30-11:30 a.m.

After Hours: See a potential environmental issue after regular business hours? Call dispatch non-emergency at 972-466-3333 for immediate assistance.

City of Carrollton, TX

Learn more about doing business in the City of Carrollton.