Every year public water suppliers are required to issue an
annual drinking water quality report to their customers before July first of
the following year. Last week WSSC Water released their 2024 report. WSSC
Water draws the water we treat from two sources: the Patuxent and Potomac
rivers. WSSC also operates 2 water filtration and treatment plants – The
Patuxent (max 56 million gallons per day and the Potomac (max 285 million
gallons a day) plants that together produce an average of 167 million gallons
per day of safe drinking water.
WSSC Water is required to report on the water quality from
these sources. WSSC Water reports that their water consistently meets all
federal (US EPA Safe Drinking Water Act) and state standards. Of the 182
compounds that are required to be tested for, very few were found in the
finished drinking water. Those found were in concentrations below the EPA’s
maximum contaminant levels under the Safe Drinking Water Act.
WSSC Water began quarterly monitoring for PFAS in 2020. WSSC
Water proactively increased PFAS monitoring from quarterly to monthly and from
18 to 29 compounds using the latest Environmental Protection Agency (EPA)
testing methods in 2022. This proactive measure goes above and beyond federal
and state requirements. Test results found very low levels of PFAS in the
drinking water.
In April 2024, the EPA announced the final regulation for
six PFAS in drinking water, setting Maximum Contaminant Levels (MCLs) of four
parts per trillion (ppt) for Perfluorooctanoic Acid (PFOA) and 4 ppt for
Perfluorooctane Sulfonic Acid (PFOS), 10 ppt for PFHxS, PFNA, and HFPO-DA
individually, and a Group Hazard Index for four PFAS compounds. This regulation
requires additional monitoring as well as certain actions for systems above the
MCLs. WSSC Water sampling results were not above the MCL.
Three emerging issues were noted in the water quality
report. The first is the rising salt level in the Potomac River. The water
filtration plants cannot remove salt. Sodium is a secondary contaminant in
drinking water it is recommended that the level be controlled below 20 mg/L by
the EPA. The reported level in the Potomac River is still below that level, but
continues to rise.
The ICPRB and the Northern Virginia Regional Commission have
developed a voluntary Salt Management Strategy published in 2020 to try and
reduce the largest source of salt/ chloride to the Potomac, its tributaries and
the Occoquan Watershed, but this alone may not slow the increasing salinization
of our source water for drinking as road construction continues at an alarming
pace. Even as we try to encourage the adoption of the voluntary salt management
strategy, we keep building roads and paving over the counties.
Sodium and chloride the elements that make up salt and break
apart in water are washed off road by rain and melting snow and flow into local
waterways or seep through soils into groundwater systems with negative impacts
on water quality and the environment. Salts pollute drinking water sources and
are very costly to remove. The only available technology to remove salt from
the source water is reverse osmosis that is expensive and requires a
significant amount of energy to run. Elevated salt levels are believed to
be a contributing factor to the brown water issues experienced by WSSC
customers.
The water was reported to be clear leaving the water
treatment plant, thus, the problem was in the distribution system. WSSC believes
that the salty snowmelt and elevated sodium and chloride levels loosened the
buildup of rust and manganese in their distribution system. The root cause, the
failure to flush the distribution system for years, has caught up with them.
Despite the appearance, WSSC reports that the water remains safe if unappealing.
This is just one symptom of the problems at WSSC.
The second problem was the presence of lead. WSSC Water
completed its latest triennial Lead and Copper Rule (LCR) tap sampling in 2023.
Ninety percent of the homes we tested had lead levels less than the analytical
reporting limit of 2.0 parts per billion (ppb) and well below the EPA’s Action
Level of 15 ppb. The EPA’s new Lead and Copper Rule was formally made effective
in October 2024. While WSSC Water removed all known lead pipes within their
owned distribution system in the early 2000s, and the water leaving the
treatment plants is lead-free, this multi-year EPA rule focuses on identifying
pipe materials, including those on private property.
Lead in drinking water predominately comes from the pipes.
Lead does not come from the Potomac and Patuxent. Instead, lead in drinking
water is picked up from the pipes on its journey into a home or in the home itself.
In the early years of public water supply the water service lines delivering
water from the water main in the street into each home were 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 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.
Lead can cause damage to the brain and kidneys and can
interfere with the production of red blood cells that carry oxygen to all parts
of your body. The greatest risk of lead exposure is to infants, young children,
and pregnant women. Scientists have linked the effects of lead on the brain
with lowered IQ in children. I am amongst the many scientists who believe there
is no safe level of lead exposure. If your home was built before 1990 the only
way to know if you have lead in your drinking water is to test.
Property owners share the responsibility for protecting themselves
and their families from lead in their home plumbing. You can take responsibility by
identifying and removing lead materials within your home plumbing and taking
steps to reduce your family’s risk. Before drinking tap water, flush your pipes
for several minutes by running your tap. You can also use a filter certified by
an American National Standards Institute accredited certifier to reduce lead in
drinking water -refrigerator water filters typically have this certification. WSSC Water has developed an inventory map where you can see the pipe material which you can find at What's Your
Pipe Type? | WSSC Water
WSSC Water treats water using a corrosion inhibitor called orthophosphate
to control corrosion, which was designated as the optimal corrosion control
treatment by the Maryland Department of the Environment (MDE). To ensure the
treatment is operating effectively, WSSC Water monitors water quality
parameters set by the MDE every 6 months.
The final emerging issue is Cyanobacteria (blue-green algae).
Algae blooms also called harmful algal bloom (HAB) or dead zones form in
summers when higher temperatures reduce the oxygen holding capacity of the
water, the air is still and especially in years of heavy rains that carry
excess nutrient pollution from cities, suburban lawns and farms. The excess
nutrient pollution combined with mild weather encourages the explosive growth
of algae fed by excessive nutrient pollution. However, toxic algal blooms are
relatively new.
In the 21st century toxic or hazardous algal blooms have
become a concern in our region. They occur when algae grow out of control when
there are favorable environmental conditions. Hazardous algal blooms, the ones
that contain the toxins, can lead to the poisoning of fish, shellfish, birds,
livestock, domestic pets and other aquatic organisms that can lead to human
health impact from eating fish or shellfish exposed to toxins as well as
drinking water contaminated by toxins. The existing water treatment plants do
not remove the toxins and toxic algal blooms could disrupt the water supply in
our region. Thus, WSSC Water monitors the reservoirs for Cyanobacteria
(blue-green algae) from July to October.
