Protections are needed for the Occoquan

This week is Source Water Protection Week. While scrolling through local news reports, I came across this news report in the Potomac Local:

“According to the airport’s operations manager Richard Allabaugh, about 11:53 p.m. on August 24, there was an accidental discharge of fire-retardant foam at the Leidos Hangar facility on Frank Marshall Lane. There had been no fire in the hanger, which is when such a system would have gone off as designed.” (Rick Horner, Potomac Local)

Mr. Allabaugh, himself, was kind enough to send me the pictures below.

The release took place at night

The berms were place to prevent the foam from leaving the site

The next morning

For the second time in less than two years Manassas Airport has had a significant release of fire suppression foam unrelated to fires. Aqueous film-forming foam, which is known as AFFF, is a firefighting foam widely used in the aviation industry because it quickly extinguishes fuel fires by spreading across the surface, depriving the fire of oxygen. This also makes a spill hard to control. The foam contains chemicals known as per- and polyfluoroalkyl substances (PFAS) that are persistent in the environment and bioaccumulate.

This time the foam did not reach the waterway and according to Mr. Allabaugh was fully contained on-site by the cleanup crew. DEQ, the County HazMat team, and Fairfax Water were appropriately notified of incident. The Manassas Airport is upstream from the Occoquan Reservoir along Cannon Branch which flows into Long Branch, and accidents do happen.  The response by the airport operations was by the book.

from Google maps

The Occoquan Reservoir consists of 1,400 acres containing 8.5 billion gallons of water that provides 40% of the daily water supply for Fairfax Water which in turn supplies Prince William Service Authority and a significant portion of Loudoun County. The reservoir’s water quality is a reflection of its watershed; spills, roadway runoff, stormwater carrying oil, salt and dirt are all carried into the Occoquan Reservoir. The water from the reservoir is then treated by the Griffith Water Treatment Plant and piped out to customers.

Forty percent of the 570 square miles of the Occoquan Watershed including the headwaters of the Occoquan are in Prince William County. When the Occoquan Reservoir was first built 1957 it was located in a rural and forested area and the water was pristine. The unrelenting growth and development in this region has changed that.  Without additional treatment lines there are limits to what contaminants the Griffith Water Treatment Plant can remove from the raw water.  Because they are water soluble, traditional water treatment technologies used by Fairfax Water are not able to remove PFAF from the raw water.

Reportedly, testing was done after the February 2020 spill of fire suppression foam that was not fully contained on site. The Occoquan Watershed Monitoring Laboratory did not find significant PFAS contamination in the Reservoir. The 8.33 billion gallons would have diluted the PFAS present if it was carried to the Reservoir, but PFAS is known as the forever chemicals because they take hundreds if not thousands of years to degrade and accumulate in people and the environment. Traces of these chemicals have become ubiquitous in our environment.  The levels of PFAS found were all below the U.S. Environmental Protection Agency’s (EPA) health advisory level of 70 ppt. The EPA has not yet established a health based MCL.  

Still, the water quality of the Occoquan Reservoir is of concern. Last fall, the Prince William County Board of Supervisors issued Directive No. 20-86 for county staff to develop a protection overlay district for the Occoquan Reservoir. County staff reports that they have reviewed a recent report prepared by the Occoquan Watershed Monitoring Lab of the Occoquan Watershed and the Reservoir System water quality. The county staff has discussed the report-findings with the Northern Virginia Regional Commission. 

Staff is also reviewing reports and recommendations from local committees and environmental groups and evaluating current design standards and development practices, in relation to water quality trends in the Reservoir. An overlay district could be used to limit the types and amount of development on land within the watershed to protect the Occoquan Reservoir to control non-point source contamination, it could also be ineffective if too loose or constantly overridden by the Board of Supervisors. Further development is a very real threat to our drinking water supply for more information see the Occoquan Watershed Monitoring Lab report.

Drug Resistant Bacteria Spreads to Our Waters

Drug resistant infections were first identified in 1960 in hospitals and called hospital-acquired MRSA (Methicillin-resistant S. aureus). MRSA causes difficult-to-treat and potentially fatal bacterial infections in hospital patients, and is sometimes referred to as a “superbug.”  However, in the late 1990s, MRSA infections began to appear outside the hospital setting in the greater community in otherwise healthy people who had not been in a hospital and had no other known risks for these kinds of infections. The incidence of these so called “community-acquired” MRSA infections has been increasing in the United States.

Peopled infected with MRSA shed the bacteria from the nose, feces, and skin; therefore, MRSA can end up in municipal wastewater streams after being washed down the drain or flushed down the toilet and spread in ways beyond direct contact.  Several scientists led by researchers at the University Of Maryland School Of Public Health, have performed a study that was published last November showing that it is possible that municipal waste­water could be a reservoir of this micro-­organism. The scientists tested water entering and leaving four unnamed waste water treatment plants, WWTPs. The mid Atlantic ones were probably Back River in Baltimore and possibly Sykesville based on their descriptions. 

They found that MRSA, as well as a related pathogen, methicillin-susceptible Staphylococcus aureus, MSSA, were present in the waste water inflow at all four WWTPs. MRSA was found to be present in 83% of the raw sewage samples taken at the plants. The percentage of MRSA and MSSA positive samples decreased as treatment within the WWTP progressed. Only one WWTP was found to have MRSA bacteria in the treated water leaving the plant, and this was at a plant that does not regularly use chlorination, a tertiary step in wastewater treatment.

In WWTPs Primary Treatment consists of sedimentation and screening of large debris using screens and large settling tanks. Until 1960’s primary treatment was the only form of sewage treatment in most sewage plants. Secondary treatments usually include biological and/or chemical treatment. One of the most common biological treatments is the activated sludge process; in which primary wastewater is mixed with bacteria that break down organic matter and cleans the water. Oxygen is pumped into the mixture. A clarifying tank allows sludge to settle to the bottom and then the treated wastewater moves on for tertiary treatment. Coagulation, filtration and disinfection take place in tertiary treatment. A coagulant is added, the commonly used high-lime process can reduce phosphorus to below 0.10 mg/L. This process also serves as a barrier to viruses, captures organics leaving secondary treatment, and precipitates heavy metals and other suspended particles. Coagulation is followed by filtration which removes organic matter, microorganisms, minerals and excess nutrients. The finalbarrier to pathogens is a chlorination and dechlorination process. 

As the University of Maryland scientists showed, plants that do not use the chlorination process could potentially be releasing disease causing bacteria into the environment.  As waste water is recycled more and more this raises concerns for the safety of the greater community being exposed to undertreated recycled water or bio solids. The odds of samples being MRSA-positive decreased as treatment progressed: 10 of 12 (83%) influent samples were MRSA-positive, while only one of 12 (8%) effluent samples was MRSA-positive. This study makes clear the need to upgrade all waste water treatment plants to advanced waste water treatment plants that use disinfection with chlorine and to eliminate the storm related untreated releases of dilute sewage by our older cities combined sewer systems. Not addressed in the study was the survival of MRSA in bio-solids, it can only be inferred to be a possibility. Our WWTPs must also be upgraded to advanced treatment of the residual sludge to Class A to ensure all bacteria is killed before the sludge is released to the greater environment and human exposure. Not all WWTP treat all their bio solids to that level, but it is possible and should be done. The city of Alexandria is an example of a plant that treats all Biosolids to Class A Exceptional Quality with even higher standards and is safe for use in community settings.

 It is possible to reuse and recycle waste water safely. Since 1978, the upper Occoquan Sewage Authority in Northern Virginia has been discharging recycled water into a stream above Occoquan Reservoir, one of the two potable water supply sources for Fairfax County, Virginia. Recycled water has been part of the Occoquan supply for 34 years and chances are if you are in Fairfax, parts of Prince William and Loudoun counties you have been regularly drinking recycled water. However, this water is always treated with tertiary treatment that includes chlorination and dechlorination before it is released back into the Occoquan and Fairfax Water fully treats and tests all water delivered as potable. The Occoquan Watershed Policy not only specified the type of waste treatment practices that would have to be adopted on a basin-wide scale, but provided for an on-going program of water quality monitoring to measure the success (or failure) of the waste water treatment. The Occoquan Watershed Laboratory (OWL), operated by the Virginia Polytechnic Institute Department of Civil Engineering conducts comprehensive studies of the Occoquan water quality, and effects of the waste water treatment effluents.

Noman M. Cole, Jr. Pollution Control Plant in Fairfax,Virginia is now engaged in a direct water recycling program, reusing treatedwastewater for landscape irrigation and industrial processes. The Noman Cole plant is engaged in the Water Reuse Project also known as the Purple Pipe Project, to directly reuse some of the water. (The pipes are colored purple to designate the water as non-potable, but have undergone chlorination to ensure water safety.) The Purple Pipe project has completed the first phase of the project and is delivering 1.4-1.6 million gallons of fully treated waste water to the Covanta Fairfax, Inc. Resource Recovery Plant and Laurel Hill Golf Course. 

The paper Methicillin-Resistant Staphylococcus aureus (MRSA) Detected at Four U.S. Wastewater Treatment Plants was written by Rachel E. Rosenberg Goldstein, Shirley A. Micallef, Shawn G. Gibbs, Johnnie A. Davis,Xin He, Ashish George, Lara M. Kleinfelter,Nicole A. Schreiber, Sampa Mukherjee, Amir Sapkota,Sam W. Joseph, and Amy R. Sapkota and published in the November 2012 issue of Environmental Health Perspectives