Public Works and Environmental Services

Fairfax County, Virginia

CONTACT INFORMATION: Our administrative offices are open 8 a.m. – 4:30 p.m., Mon - Fri

TTY 711

12000 Government Center Parkway
Suite 449, Fairfax, Va 22035

Craig Carinci,
Director, Stormwater Planning

Cooling Towers

Cooling Towers

Cooling towers are often used with air conditioning systems to make large commercial buildings feel comfortable. They are also used for cooling industrial processes that create a lot of heat. Cooling towers work by circulating water through pipes to remove unwanted heat.

Cooling towers release water at times, for instance, during maintenance. The water may contain chemicals to prevent algae, corrosion and scale; heavy metals; sediments; and other pollutants. These pollutants can harm fish and wildlife and degrade water quality if they flow into the storm drainage system or local streams.

Fairfax County must approve cooling tower connections to the public sanitary sewer or the county storm drainage system, which are two separate systems. Water released from a cooling tower is not allowed to flow into the storm drainage system unless it complies with state and local water quality regulations

The Virginia Pollutant Discharge Elimination System (VPDES) permit program limits the amount of pollutants that are allowed to flow into state waters. Under the program, Virginia Department of Environmental Quality (DEQ) issues permits for noncontact cooling water discharges; that is, cooling water that does not come in direct contact with raw materials, products or wastes. Permittees need to pay permit registration fees, monitor discharges from their cooling towers and submit monitoring reports.

The Stormwater Management Ordinance (Chapter 124 of the Fairfax County Code), prohibits discharges of non-stormwater to state waters unless the discharge is authorized by a state permit. Any unauthorized discharges to state waters through the county storm drainage system is considered an illicit discharge. Owners of existing cooling towers are required to correct violations in a timely fashion. If uncorrected, a violation may result in a civil penalty in an amount not to exceed $32,500 according to the County Code Section 124-8-3. Each day of a violation constitutes a separate offense.

Cooling Tower Fact Sheet

Fairfax County has prepared information to help owners and operators of cooling towers to comply with state and local water quality regulations.
Cooling Towers: Options for Property Owners

Frequently Asked Questions about Cooling Tower Discharges

1. Who can I contact for help in determining what permits and reviews are required?

Please contact the Land Development Services Customer Service Ombudsman at 703-222- 0801, #2, for permitting help and minimum submission requirements. Customers may also visit the Permit Application Center on the second floor of the Herrity Building at 12055 Government Center Parkway, Fairfax.

During the COVID-19 pandemic, the second floor of the Herrity Building is not open to the public. Please contact LDS via email

2. Do I need a Virginia Pollutant Discharge Elimination System (VPDES) permit to discharge to a storm drain?

All discharges of non-contact cooling water are subject to the VPDES general permit regulation governing point source discharges of non-contact cooling water of 50,000 gallons per day or less to surface waters. This permit is administered by the Virginia Department of Environmental Quality (DEQ).

Discharges greater than 50,000 gallons per day would be subject to an individual permit, also administered by DEQ.

3. How do I determine the registration fee amount for a VPDES non-contact cooling water general permit?

Please call DEQ at 703-583-3800.

4. My company manages several buildings that have cooling tower discharges that flow to the storm drainage system. Does each building require a separate permit?

One VPDES non-contact cooling water general permit can cover multiple buildings if the cooling tower discharges, as a whole, do not exceed 50,000 gallons per day and all buildings are located within one contiguous campus. DEQ will make the final determination on this during the permit issuance process.

5. My cooling tower discharges into a stormwater management facility (i.e. dry pond, wet pond, underground detention, etc.). Do I still need a VPDES permit?

DEQ may consider the presence of stormwater management facilities when they review the permit application. If there is a potential for the pollutants to reach surface waters then a permit may still be required. If you have further question, please call DEQ at 703-583-3800.

6. If my permitted cooling tower does not produce an overabundance of chemicals or pollutants, can my permit be terminated?

DEQ will evaluate stormwater discharges associated with non-contact cooling tower water on a case-by-case basis. According to the general permit, a permit termination may be requested if the cooling tower changes discharge locations (i.e. plumb the discharge to the sanitary sewer) or the building changes ownership.

Please contact Fairfax County's Industrial Waste Section at 703-550-9740 x252, TTY 771, before changing the discharge location from the stormwater system to the sanitary system. For questions about obtaining a plumbing permit, please contact the Land Development Services Customer Service Ombudsman at 703-324-1528, TTY 711.

7. Are there certain chemicals that DEQ allows to be discharged?

Discharges must comply with Virginia Water Quality Standards. Please refer to the general permit regulation at 9VAC 25-196-50 for examples of substances that are not allowed.

DEQ does not maintain a list of approved commercial products.

8. Does Fairfax County provide a list of contractors/companies that can monitor the cooling tower discharge per the general permit requirements?

Neither Fairfax County nor DEQ maintains a list of companies to contact related to a permit's monitoring requirement. Any laboratory selected by the permittee must comply with Part II.A of the VPDES non-contact cooling water general permit.

9. I want to change a cooling tower connection from the storm drainage system to the sanitary sewer. What are the requirements for this change?

The proposed discharge will be evaluated as part of the Land Development Services permit review (see Question #1). Requirements for discharge authorization include:

  • The discharge flow rate must not exceed the available sewer capacity.
  • Water treatment additives must be compatible with the publicly owned treatment works; discharge prohibitions and standards are provided in Chapter 67.1, Article 2 of Fairfax County Code and local pretreatment limits for applicable sewer service areas, respectively. In addition, additives containing brominated compounds are prohibited from discharge to the Upper Occoquan Service Authority’s Regional Water Reclamation Plant located in the western part of Fairfax County.
  • The discharge must be metered for billing purposes (except low discharge volumes).

Please check back periodically for more answers to FAQs.

For additional information, email the Stormwater Planning Division or call 703-324-5500, TTY 711.

Fairfax Virtual Assistant