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Water Quality
ACSA works tirelessly to provide our customers with high-quality, reliable and safe drinking water at a reasonable rate. Our raw water is supplied from local rivers and reservoirs and is pumped to one of five water treatment plants, all owned and operated by the Rivanna Water and Sewer Authority (RWSA). These plants are equipped with advanced filtration and treatment systems to ensure safe, clean and reliable water for your home or business. Learn more below about how Albemarle County water is treated and delivered to your tap.

ACSA’s Water Treatment Process
Once raw water arrives at a treatment plant, it is treated with a coagulant, the pH is adjusted and the water is mixed to help particulates stick together. The flocculation basins are where the water flow is slowed to allow the particulates to stick to other particulates. When the water flows to the sedimentation basins, the particulates sink to the bottom and are removed. The water then flows through several large filters, removing the remaining microscopic particles and microorganisms. Thereafter, chlorine is added to disinfect the water. Final treatment includes further adjustment of the pH before it reaches your faucets.
How We Monitor Water Quality
All water sampling is conducted by our wholesaler, Rivanna Water and Sewer Authority (RWSA). Results of annual water sampling can be found in your Annual Consumer Confidence Report, which details all testing and ensures transparency about the quality of ACSA water. For more in-depth information on the sampling and treatment processes, please contact the Rivanna Water and Sewer Authority.
Do you have questions about water quality?
Internal Issues of Mold
Based on inquiry calls and complaints received over the past several years and the specific request made by the Old Trail Homeowners Association in Crozet, testing of mold on various surfaces within several customer homes in Crozet and the Charlottesville urban area has been conducted. The effort was two-fold:
- Identify the specific type(s) of mold that customers have experienced, typically as a black ring in the toilet or as a growth of the aerator screen of a faucet; and
- Confirm that the mold is not present in the ACSA water, providing proof that the growth is indeed internal.
The certified laboratory Hayes Microbial Consulting performed testing on samples collected in multiple homes and businesses that filed complaints. Swab samples were collected from locations such as toilets, faucet aerators, bathtub mats and washing machines. In addition, a water sample was collected from each site using a sink from which the aerator was removed from the faucet.
The swab samples showed common molds including Cladosporium, Aspergillus and Penicillium. These fungi are the most typical found in our environment with the first being among the most widespread types of mold in the world.
However, no fungi were detected in any of the water samples. In other words, mold is not present in ACSA water being delivered to our customers’ homes or businesses. Our water is clean, safe, and meets or exceeds all regulatory standards.
Additionally, none of the swabs showed the dangerous “black mold” Stachybotrys, which typically grows on damp drywall or wallpaper.
Pink Stains or Growth
You may have noticed pink-colored “stains” or growths that can develop in moist areas in your home, particularly in the bathroom and especially in the warm-weather months. You may see these growths around a tub or sink drain, on a folded portion of a shower curtain, in a toilet bowl or even in your pet’s water dish — and then wonder if there is something wrong with your water.
It is important to note that pink residue is not a problem with your water quality, and it is not harmful in this situation.
It is evidence of a kind of bacteria that can commonly grow in these conditions. The most typical of these bacteria has the scientific name of Serratia marcescens. These bacteria do not enter your home or business in our water. Rather, the constantly moist surfaces mentioned above provide a great place for them to grow.
These bacteria typically come from soil, dust or mulch entering your home as microscopic spores in the air, on clothing or on pets. A pink stain or film can also occur during or after construction when dirt and dust containing Serratia are disturbed. The problem is often more noticeable in the summer months when air and water temperatures and humidity are higher, especially if windows are kept open for any length of time.
Serratia will not survive in chlorinated drinking water. However, where water stands for any length of time (such as in a toilet, around a drain or on a shower curtain), the chlorine disinfectant dissipates to the air, and the pink color may develop. Customers who remove the chlorine from their water by use of an activated carbon filter may even be more likely to experience the problem.