Loudoun Water Pretreatment Program
The term "pretreatment" refers to the reduction, elimination or alteration of the amount or nature of pollutants from commercial and industrial facilities prior to discharging to a sanitary sewer collection and treatment system. Loudoun Water's pretreatment program is a Clean Water Act mandated program that requires Loudoun Water to control industrial and commercial discharges to our sanitary sewer collection and treatment system, thereby reducing the amount of pollutants released to the environment from our wastewater treatment plant. Wastewater from certain industrial and commercial sources may contain pollutants at levels that could interfere with or pass through the wastewater treatment processes.

Loudoun Water’s Pretreatment Program has the following objectives:

  • Enforce all applicable Federal, State and Local Regulations to ensure the protection of public health and the environment.
  • Maintain the quality of treated wastewater and biosolids so that they may be beneficially reused as “reclaimed water” and fertilizer.
  • Protect the Broad Run Water Reclamation Facility from any pollutants that may interfere with treatment processes.
  • Prevent the introduction of pollutants to our wastewater collection system that may pass through the Broad Run Water Reclamation Facility untreated and ultimately to the environment.

Loudoun Water meets its objectives by establishing local discharge standards (Ie: Local Limits) for pollutants of concern permitting Significant and Non-Significant Industrial Users, testing industrial user discharges for compliance with permit limits, and routinely conducting comprehensive facility inspections.

Wastewater Discharge Standards
The pretreatment program enforces discharge standards established by the USEPA, known as Categorical Pretreatment Standards, as well as Local Limits that are specific to wastewater that flows into the Broad Run Water Reclamation Facility. The wastewater of some customers within Loudoun Water’s service area flows to the Blue Plains Advanced Wastewater Treatment Plant and is held to Local Limits established by DC Water. Local Limits apply to non-domestic sources and are reviewed generally every five years. Industries may be required to pretreat their wastewater discharge if the pollutants exceed or have the potential to exceed the allowable discharge concentrations.


Technically Based Local Limits for the Broad Run Water Reclamation Facility, Published 2017

Parameter Local Limit
Arsenic 0.23 mg/L
Cadmium 0.07 mg/L
Chromium 2.7 mg/L
Copper 2.3 mg/L
Cyanide 0.06 mg/L
Lead 1.0 mg/L
Mercury 0.046 mg/L
Molybdenum 0.7 mg/L
Nickel 1.5 mg/L
Selenium 0.24 mg/L
Silver 1.75 mg/L
Zinc 11.2 mg/L
pH 5.0-10.0 SU
Fats, Oils & Grease (FOG)

50 mg/L solidifying @ <150ºC
50 mg/L hydrocarbon FOG
100 mg/L total FOG

Temperature 40ºC (104ºF) at POTW; 60ºC (140ºF) from S|U
Flammability No 2 consecutive readings at 25% LEL, and no reading of greater than or equal to 10% LEL allowed

All violations of discharge limitations and permit requirements are met with enforcement action. This enforcement action is outlined in Loudoun Water’s Enforcement Response Plan.

Wastewater Discharge Permits
Commercial, industrial and government agencies that meet any of the following criteria are required to have a Loudoun Water issued Wastewater Discharge Permit:

  • Users with an average process wastewater flow of 25,000 gallons or more per day.
  • Users who contribute 5% or more of the total inflow or organic loading to Broad Run Water Reclamation Facility.
  • Federally mandated categorical industries — detailed on the EPA's website.
  • Users who have a reasonable potential to adversely affect the operations of Broad Run Water Reclamation Facility or for violating any pretreatment standard or requirement.

Industrial Waste Survey (IWS)
Loudoun Water continually surveys businesses to determine if a reasonable potential exists to adversely affect the wastewater reclamation facility or violate any Federal standard or Local Limits. Loudoun Water evaluates the information and, if necessary, samples wastewater discharges to confirm if a business should be subject to pretreatment requirements.