Maintenance and Service

• Drinking Water Quality & PFAS

  Herndon purchases its water from Fairfax Water.  The treatment process used by Fairfax Water treats for viruses such as COVID-19. Transmission of the virus is not a risk in treated drinking water. Disinfectants, like chlorine, used to treat drinking water are effective in inactivating COVID-19. 

  Fairfax Water's Statement on EPA's Final PFAS Standards for Drinking Water

• Flushing - Do's and Don'ts

  

  Please limit what you flush down the toilet to biodegradable toilet paper and human waste.  Flushing  improper materials can damage sewage pumps, cause sewage back-ups, and force increased emergency repairs or maintenance of the sewer system.  Toilet wipes that are often advertised as flushable can clog and damage pumps.

   

  To prevent backups, do not flush:

  • Baby wipes or disinfectant wipes
  • Rags, cloth or clothing  
  • Sanitary napkins, tampons, condoms or any non-organic material
  • Q-tips®
  • Napkins or paper towels
  • Contact lenses
  • Plastic of any kind
  • Food items of any kind
  • Hair
  • Diapers (cloth, disposable or “flushable”)
  • Facial tissues
  • Dental floss
  • Fats, Oils or Grease
  • Medicines or other pharmaceuticals, including liquids

• Hydrant Flushing - Spring Schedule

  Each spring, the Town of Herndon flushes its water mains by opening fire hydrants and allowing them to flow freely for a short period of time. We do this to maintain the high quality of water in our distribution system.

  Flushing may result in some temporary discoloration and the presence of sediment in your water. These conditions are not harmful and should be of very short duration. Running your cold water for a few moments should help clear the line.

  Temporary Change to Free Chlorine 

  During this period of time, a slight change is made in the water treatment process to facilitate an effective flushing program. Throughout the year, chloramines, or combined chlorine, is added to the water as the primary disinfectant. During the spring flushing program, chlorine is added in an uncombined state, commonly referred to as free chlorine. Free chlorine is somewhat more volatile than combined, providing exceptional availability to react with sediments suspended during flushing. Fairfax Water will use free chlorine as the primary disinfectant from April through July. Depending on your location within the distribution system and usage patterns, it could take up to a week for your drinking water to transition from combined to free chlorine at the beginning of April, or from free chlorine to combined chlorine at the beginning of July.

  You may notice a chlorine taste and odor in your drinking water while free chlorine is utilized. If you are especially sensitive to the taste and odor of chlorine, try keeping an open container of drinking water in your refrigerator. This will enable the chlorine to dissipate thus reducing the chlorine taste. Remember - drinking water has a shelf life! Change out the water in your refrigerated container weekly.

  Please note: If you have an aquarium or pond always test the water you add to your aquatic environment to be sure it is free of any chlorine before adding fish or other animals. Chemical additives with directions for removing either free chlorine or chloramines from water for use in fish tanks or ponds are available at pet/fish supply stores.
  
  

• Sewer Lining and Maintenance

  The town’s annual sewer lining and maintenance project takes place town-wide and is intended to improve the town’s  sewer system and prevent costly repairs due to failing sewer mains.  The program typically begins in early January and is completed by the end of March.

   

  
  

• Valve Maintenance

  The Department of Public Works conducts water valve maintenance throughout the town. The purpose of the program is to exercise main line valves throughout the distribution system to assure reliable operation and maintain water quality. The American Water Works Association recommends operation of main line valves periodically to prevent build-up of deposits which may render the valve inoperable.

  A main line valve is a valve which is installed at certain points in the water main system, usually at an intersection where the main may run in different directions or where access needs to be controlled remotely as with a fire hydrant. The valves provide a means of isolating small lengths of main in the event of a necessary shut down for emergencies or maintenance. The valves are generally in the street located under small lids covering valve boxes, usually about 6 inches in diameter. The program will provide an opportunity to check the condition of the valve box, as well as all aspects of valve operation.

  During this program, crews will exercise the valves by operating the valve through a full cycle and returning it to its normal position. Where valves are exercised, a fire hydrant will be flowed to ensure that the water in the mains will remain clear.

  All care is taken to minimize any potential impact on water quality. Even with these precautions, some discolored water is possible. Flushing may result in some temporary discoloration and the presence of sediment in your water. These conditions are not harmful and should be of short duration. If you have questions about this program or the work being conducted in your area, you may contact the Department of Public Works.

  
  

• Water Main Standards

  • Water Main Design and Construction Standards

• Water Peak FAQ

  During the summer and fall months, the town charges a peak rate for water usage. This rate can actually save you money.

   

  What is water peak or peak usage?

  Peak usage refers to the consumption of water in excess of the average consumption of the preceding two winter quarter billing periods (winter quarterly average). Peak usage is currently billed at the rate of $6.94/1 thousand gallons. *All customers will see this line on their bills during peak usage billing months, however, unless your usage during the peak billing months exceeds that of your winter quarterly average, your charges calculation will remain unchanged*.

   

  How does this actually save me money?

  If you use more water during the warmer months of the year (watering lawns, washing cars, etc.), you will save $0.82/1 thousand gallons on sewer usage for fiscal year 2022 and $1.52/1 thousand gallons for fiscal year 2023. This is because during non-peak billing months the consumption gal­lons for water and sewer are charged equally, but sewer usage charges are capped during peak billing months. Example: a homeowner who uses 20 thousand gallons of water in a month with normal rates is also billed for 20 thousand gallons of sewer usage. A homeowner who uses 30 thousand gallons of water in a peak month is charged the peak rate on any amount above his/her average (in this case, 10 thousand gallons) but is NOT charged for sewer usage on amounts above the cap/average. The net result is savings for the homeowner.

   

  What are the peak usage billing periods (months)?

  Peak billing months are June, July, August, September, October and November.

   

  Questions? Please contact us at 703-435-6814 or utilities@herndon-va.gov.

• Water Quality Reports

  • 2023 Water Quality Report 
  • 2022 Water Quality Report
  • 2021 Water Quality Report
  • 2020 Water Quality Report 
  • 2019 Water Quality Report 
  • 2018 Water Quality Report