Public Works and Environmental Services

CONTACT INFORMATION: Our administrative offices are open 8 a.m. – 4:30 p.m., Mon - Fri
703-324-5500 TTY 711
12000 Government Center Parkway
Suite 449, Fairfax, Va 22035
Joni Calmbacher
Director, Stormwater Planning

Industrial and High Risk Runoff (IHRR) Program

Industrial Maintenance Facility
Industrial Maintenance Facility
Good Drum Storage Practices
Good Drum Storage Practices
Good Drum Storage Practices
Good Drum Storage Practices

Industrial and High Risk Runoff (IHRR) Program

Fairfax County's Municipal Separate Storm Sewer System (MS4) permit requires the county to implement an industrial and high risk runoff (IHRR) program. The purpose of the IHRR program is to identify and control pollutants in stormwater discharges to the MS4 (also known as the county storm drainage system), from IHRR facilities and any other industrial or commercial discharges the county determines are contributing a significant pollutant loading to the MS4. One way the county fulfills this permit requirement is through routine inspections of IHRR facilities.

What Is an IHRR Facility?

Based on the MS4 permit, Fairfax County has identified the following types of facilities as potential industrial and high risk facilities:

  • Municipal landfill, other treatment, storage or disposal facility for municipal waste.
  • Hazardous waste treatment, storage, disposal and recovery facility.
  • Facility that is subject to Emergency Planning and Community Right-To-Know Act (EPCRA) Title III, Section 313.
  • VPDES industrial stormwater permitted facility.
  • Facilities and operations identified in 40 Code of Federal Regulations (CFR) 122.26(b)(14) with manufacturing, processing or raw materials storage outside that do not have coverage under an existing VPDES industrial stormwater permit.
  • Major automotive facilities such as repair shops, body shops, auto detailers, tire repair shops and service stations.

Other types of facilities may be designated high risk if the county has noted repeated stormwater issues at the facilities. A "high risk facility" is any commercial or industrial facility that has caused a discharge that has contributed a significant pollutant load to the MS4 on a recurring basis. For example, a food service establishment or landscape business may be designated a high risk facility if it improperly manages wastes and repeatedly contributes pollutants to the county MS4.

Who May be Inspected?

The IHRR program applies to those IHRR facilities listed above that drain to Fairfax County's MS4. To determine whether your facility would be subject to inspection call 703-324-5500, TTY 711 or email the Fairfax County Stormwater Planning Division.

What is a Facility Inspection?

  • A county stormwater inspector will look at the area (s) where the facility's storm drainage enters Fairfax County's MS4.
  • If the inspector does not find flow or any other evidence of pollution, the inspection may be concluded. However, if the inspector finds flow at the connections to the county MS4, the inspector may collect a sample to test for evidence of pollutants.
  • If the sample test results indicate pollution, then the inspector will coordinate with the facility manager/owner to determine the source of the pollution.
  • When the pollutant source is found, the inspector will request that the discharge be corrected. The request may be in the form of a written corrective action notice that explains the problem that the facility must correct. The inspector may also recommend best management practices and provide educational materials to the owner/operator.
  • Afterwards, the inspector may keep in touch with the owner/manager through phone, correspondence or site visits to check on progress.
  • The inspector may perform a final site visit to verify that the problem has been corrected.
  • If sample results indicate no pollution, then the inspector may offer to tour the site and provide suggestions on best management practices.


A goal of the IHRR program is to inform commercial and industrial facilities of best management practices, or BMPs, that minimize or eliminate the discharge of pollutants into the county's MS4. A summary of BMPs can be found under Pollution Prevention.

Photo - Using Booms and vacuum System to Capture Wash Water
Using Booms and Vacuum System to Capture Wash Water. Fairfax County Photo.


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