Water Quality in the Bull Run and Evergreen System

 As of July 1, 2024 Prince William Service Authority was rebranded as Prince William Water to more clearly convey what it is that they do and also to stop confusing them in internet searches with Pittsburgh Water and Sewer Authority who was also using PWSA.

Prince William Water has posted their 2024 Water Quality Report that covers the testing that took place during the 2023 year. PW Water met or exceeded all federal and state water quality requirements for calendar year 2023. It is to be noted that most of the water that PW Water delivers to customers is purchased from Fairfax Water (15   million gallons a day from the Occoquan Reservoir and 9 million gallons a day from the Potomac) and Manassas ( 5 million gallons a day). However, the Bull Run Mountain and Evergreen System  gets its water from six groundwater wells located throughout the Bull Run Mountain and Evergreen Water System, and  provides an average of 92,000 gallons of water per day for their customers. The Service Authority has operated the groundwater well system since 1990.

The water quality data from the Bull Run Mountain and Evergreen System caused me  pause. The water quality is only treated for corrosiveness, and meets all state and federal Safe Drinking Water Act standards. However, the testing under the Lead and Copper Rule found the presence of lead in the first draw samples. The Lead and Copper Rule requires community water systems to monitor lead and copper levels at the consumers' taps. If action levels are exceeded, installation of corrosion control treatment is required. If the action level for lead is exceeded, public notification is required.

from PW Water

Compliance with the lead and copper action levels is based on the 90th percentile lead and copper levels. This means that the concentration of lead and copper must be less than or equal to the action level in at least 90% of the samples collected. The regulations tell you exactly how to calculate that result based on the number of samples taken and how many samples need to be collected. Prince William Water, though only required to collect 10 samples collected 14 due to good response rates. With 13-17 samples the EPA states that you should average the second and third highest sample results to get the 90th percentile level. The level of lead in the drinking water calculated in this way was 4.6 parts per billion. This is below the 15 μg/L μg/L or parts per billion action level. However, the U.S. Environmental Protection Agency (USEPA) Lead and Copper Rule lead action level of 15 μg/L is not a health-based standard, rather it is used to identify system-wide contamination. There is no safe level of lead exposure. Water lead levels as below 5 μg/L can increase a child’s blood lead level and cause permanent damage to biological and developmental processes.

The Lead and Copper Rule requires systems to monitor drinking water at customer taps. If lead concentrations exceed an action level of 15 μg/L the system must undertake a number of additional actions to control corrosion. The good news is that the Bull Run and Evergreen Water System is already controlling for pH because some of the wells produce slightly acidic water that would over time tend to damage pipes and plumbing fixtures.  We do not know where in the system the lead is coming from. Future testing under the revisions to the Lead and Copper Rule may give use some answers. Under the newist revisions testing for lead would require a first draw and a flushed sample (technically the 5^th sample). This would tell us if the lead is coming from the home or from the well or distribution system and entering the home in the water delivered to the home.

The presence of lead in drinking water in homes supplied by both municipal service and private wells has been linked to the corrosion of lead-bearing plumbing components. In older homes the water service lines delivering water from the water main in the street into each home were once commonly made of lead. This practice began to fade by the 1950’s but was legal until 1988. Lead was also used to solder copper pipes together before 1988 (when the 1986 ban on lead in paint and solder went into effect). Also, until very recently, (2011 Reduction of Lead in Drinking Water Act) almost all drinking water fixtures were made from brass containing up to 8% lead, even if they carry a plated veneer of chrome, nickel or brushed aluminum and were sold as "lead-free." So even homes built with PVC piping in the 2000’s may have some lead in most of the faucets.

Galvanized iron is still commonly used for well casings and fittings and drop pipes in well deeper than 600 feet. Before 2014 Prime Western grade “lead free” galvanized steel zinc coating was required to contain between 0.5%-1.4% lead. After 2014, “lead free” galvanized steel have less than 0.25% lead in the surface coatings. Nonetheless, under corrosive conditions, any lead used in coatings can be easily released to the water and pumped to the household tap or accumulate in scale layers on the pipe surface or well bottom where scale can accumulate and be released or picked up and pumped with the water.

Corrosive water is the primary risk for lead in well water. However, over time water with a neutral pH could dissolve the coating on galvanized iron and in brass well components. The well completion reports do not document materials used for well components in Virginia or anywhere else to my knowledge. Once installed a well casing cannot be removed. It is possible to line the casing with a plastic pipe a technique used to seal a well where the grouting has failed. All the other components of the well can be replaced, though excavation would be required to replace the exterior portions of the pitless adaptor. However, scale that has accumulated on the bottom of the well might remain a source of lead if it is not mechanically removed.

Fortunately, addressing lead in water is very easy. Install an end-of-tap water filter. Look for filters certified by the National Sanitation Foundation (NSF) for lead removal and reduction. Install this filter on the tap you use most often for cooking or for water to drink. You probably already have on your refrigerator. Be aware that these small units are limited in the amount of time that the filter is effective in removing lead.  There are also whole house filters that have the NSF certification that are more expensive, but might be a better solution.