Chlorine

Between April and June, a slight change is made in the water treatment process to facilitate an effective flushing program and maintain water quality. During most of the year, chloramine (ammonia and chlorine) is added to drinking water as the primary disinfectant. In spring, our drinking water providers switch to free chlorine. This temporary change in the water treatment process helps prevent bacteria from becoming overly resistant.  

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 chlorine taste and odor. 
 

If chlorine is not removed before using in your aquarium, Prince William Water tap water can harm fish. Prince William Water flushes with free chlorine from April to June and utilizes chloramines, a chlorine-ammonia mixture, the rest of the year. Ask your pet retailer about chlorine and chloramine removal.

No, customers must take precautions to remove or neutralize chloramines and free chlorine in water used in fish tanks and ponds.

To prevent algae and bacterial growth in pools, it is important that pool owners maintain the same chlorine level in water treated with free chlorine or chloramines. Pool supply stores can provide more information and guidance about chlorinating pools.

Water must be treated to remove free chlorine and chloramines before use in dialysis. We notify all centers in our service area about the conversion to free chlorine each year before switching the disinfectant from chloramines. 

Dialysis patients can safely drink water treated with either free chlorine or chloramines.

Rubber components and materials, which can deteriorate over time, are sometimes used in older home plumbing systems and water heaters. When replacing rubber plumbing components, ask for chloramine-resistant parts, which you can get from your plumber or at hardware stores. Follow manufacturers' recommended use for chloramine-resistant parts.

To remove chlorine smell and taste from tap water, fill a pitcher with water and leave it uncovered on your counter or in your refrigerator. Within a couple of hours, the chlorine will dissipate. 

The use of free chlorine may result in a slight chlorine odor in your tap water. Each individual customer has his or her own sensitivity level to the taste and/or odor of free chlorine, though many detect no change at all.

Every spring, the City of Manassas and Fairfax Water, the drinking water suppliers to Prince William Water, temporarily switch from using chloramines as the main disinfectant in their water treatment process to free chlorine. According to our water suppliers, this short-term change is a best practice for the drinking water industry and makes it easier to implement a flushing program for the distribution system.

Free chlorine is also used to disinfect drinking water, but it is a stronger disinfectant than chloramines.

Chloramines are a disinfectant used in drinking water to remove bacteria and viruses. 

Our Water Quality Report provides up-to-date information about the quality of your water.

For more information, please contact Prince William Water’s Regulatory Affairs Office at (703) 331-4162 or email water_quality@pwwater.org. 
 

To protect public health, the EPA creates national regulations. These drinking water standards are enforced by VDH in Virginia. Prince William Water sends VDH its water quality test findings monthly and annually to ensure the utility fulfills federal and state drinking water regulations. If a water quality violation occurs, Prince William Water must notify VDH and its customers immediately and work with VDH to correct it.

Fairfax Water, which supplies most Prince William Water drinking water, disinfects with ozone and chloramines. Some of our western Prince William clients get drinking water from Manassas, which disinfects using chloramines. In spring, Prince William Water's water providers clean drinking water with free chlorine, a stronger disinfectant, to prevent bacteria from developing resistances.

Free chlorine and chloramines react with organic materials like decaying plant material in water to generate disinfection byproducts (DBPs). EPA and VDH regulate DBPs, Total Trihalomethanes (TTHM) and Haloacetic Acids (HAA5).  

TTHM and HAA5 sample results in Prince William Water's distribution system are regularly below the EPA standard, which Virginia Department of Health enforces.  

Certain cancers have been linked to chronic DBP exposure. The World Health Organization estimates that aquatic microorganisms pose 10,000 to 1 million times the risk of cancer from DBPs. Chloramines produce less DBPs than free chlorine because their chemical nature makes them less reactive to organic materials.