Levee relief well design could take up to 3 years
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Over the course of the next three years an engineering company will be designing relief wells and doing studies as part of the Greater Williamsport levee recertification and accreditation project.
WSP, formerly Wood Engineers, has a long history on the project, which began about a dozen years ago when the Federal Emergency Management Agency tasked those protected by the levee to bring it up to standards set for levees built by the Army Corps of Engineers after Hurricane Katrina caused damage to levees in 2005. The project involved the City of Williamsport, South Williamsport, Old Lycoming and Loyalsock townships.
Most recently, the Greater Williamsport levee project received an $8 million federal government earmark for the continued efforts toward recertification, a process that will continue for several years. If it is not recertified and accredited, those protected by the levee must pay for federal flood insurance.
WSP was hired by City Council and among its roles, of late, will be design of more than 100 relief wells on the dry side of the levee.
The project manager told council that ground water taken from the left bank of Lycoming Creek samples contains chemicals that were used in the industrial process.
Councilman Randy Allison, a veteran on council and former council president, asked if that issue was a concern, as he was familiar it was an area that was included in the Environmental Protection Agency Superfund identified Textron-Avco-Lycoming plume, which has been under remediation for at least 25 to 30 years.
Council is privy to annual reports about the groundwater contamination levels, information that describes the active treatment going on in conjunction with the Williamsport Municipal Sanitary and Water Authority.
WSP also has a connection with a hydrogeologist out of Pittsburgh who has been working on the remediation of the plume for the last 30 years, council was told. WSP officials said they anticipated plume tests and were able to get his services without any conflict of interest.
An earlier study concluded that during a flood event, the directional flow of groundwater would actually push cleaner water through the wells and you would not experience a polluting event during a flood event because of the way the groundwater would travel.
The concern for WSP is when drilling pump testing is done and the possibility of generating potential waste materials.
The company wants to make sure it considers the flow of those wells and also address the future pump testing for the city when designing the wells.
The city has a permit with the state Department of Environmental Protection in the region for pump testing the wells. The wells are to be tested every five years.
For wells around that plume, the water has to be collected, sampled and potentially treated before it can be released.
That is quite expensive so engineers may be looking for a way within design of new wells to reduce the burden and maintenance and to maintain and manage that better.
WSP wants to make sure that water flowing out can be contained and will determine if there are better ways than having tanks be on the sites every five years.
The Environmental Protection Agency Superfund site and plume near Lycoming Creek in Williamsport have been in place for many years.
Officials monitoring the ground water and testing it recognize the importance of safety for the residents.
WSP, an engineering firm working with the city on the Greater Williamsport levee project, recently briefed the City Council as it is tasked to design relief wells for the levee recertification and accreditation.
The testing of groundwater potentially impacted by industry has been a decades old remediation effort.
In the early 1980s, the Safe Water Drinking Act required various community water authorities to start monitoring levels of newer contaminants, including trihalomethanes. Trihalomethanes are chemicals that are a byproduct of chlorinating drinking water.
Formerly, the authority bought a gas chromatograph and based on increasing knowledge of groundwater contamination by volatile organic chemicals, initial tests were done at the Williamsport Municipal Water Authority wellfield. A team noticed elevated concentrations of trichloroethylene (TCE) in some of the wells to the north.
Groundwater contamination was tracked and looked for at groundwater relief wells along the levee system. The TCE concentrations increased as testing went north toward Fourth Street, and the officials recognized there was a plume of contamination.
A precursor to the Department of Environmental Protection (DEP) traced the contamination from that point to the AVCO Lycoming plant.
What was determined was there were two different plumes. One in the shallow aquifer moving south and one in the bedrock aquifer moving to the southwest.
The chemical could have been from making aircraft engines for the Korean War or even the second World War. Apparently spent solvents used to clean engine parts could have been dumped there, according to a former authority member.
State officials noted "significant levels of chlorinated solvents in the water, over 15,000 parts per billion (ppb) with a maximum contaminant level (MCL) of 5 ppb for trichloroethylene in the 1980s in samples from an on-site well."
According to the EPA report there was also heavy metals contamination at the AVCO plant location.
The heavy metal contamination may have been from cadmium and chromium that was used in plating engine parts.
The site was placed on the federal Superfund list in 1990, and since that time, there have been numerous additional soil and groundwater remedial efforts as technology and the knowledge of the site has improved.
The EPA Superfund program began in the late 1970s, as several toxic waste dumps received national attention when the public learned about the risks to human health and the environment posed by contaminated sites.
In response, Congress established the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) in 1980.
The act, known informally as Superfund, allows the EPA to clean up contaminated sites while forcing parties responsible to perform cleanups or reimburse the government for EPA-led cleanup work.
The lead entity with respect to oversight on federal CERCLA Superfund sites is the EPA, with the state DEP participating in all of the work along the way to make sure all of the requirements are met and citizens are protected.
Over the years, groundwater pump and treatment systems continue to operate and significantly have reduced the concentrations in the groundwater plume.
Vapor intrusion of contaminants from the plume were discovered at three nearby residences.
However, to date, there has been no ongoing risk from the city site found as testing will continue.