Contractors working for the U.S. Army Corps of Engineers Pittsburgh District install a 23-foot-tall concrete shaft enclosure weighing approximately 120,000 pounds as part of the guard wall at the Monongahela River Locks and Dam 4 in Charleroi, Pennsylvania, Nov. 16, 2023.

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Environmental engineers monitor water quality through groundwater sampling

Louisville District
Published June 17, 2022
Updated: June 17, 2022

Whether it is a current or formerly owned, leased or Department of Defense possessed property, the U.S. Army Corps of Engineers Louisville District manages the environmental restoration of sites contaminated with hazardous, toxic or radioactive waste or ordnance in Michigan, Illinois, Indiana, Ohio and Kentucky.

Through the Formerly Used Defense Sites, Installation Restoration, Base Realignment and Closure, Interagency and International Services and Environmental Quality programs, the environmental section aims to protect human health and the environment.

One tool the environmental section installs to use in the restoration process are groundwater monitoring wells. These wells provide samples of groundwater, which are tested for hazardous or toxic contaminants that could possibly cause a risk to people and the environment. Sampling data shows the concentration of harmful chemicals in the groundwater, which is compared to federal and state limits.

The most accurate groundwater samples come from wells that have been installed and properly developed at a site. The quickest method to collect groundwater samples is to bore directly into the aquifer to obtain the sample. The U.S. Army Corps of Engineers primarily uses a low-flow groundwater sampling method, which slowly pumps the groundwater without disturbing the aquifer itself.

The first step to collect groundwater samples is to make sure the water that is collected is representative of the aquifer. Members of the environmental section collect measurements of water quality, such as pH, temperature, dissolved oxygen, clarity, and others.

As the water is drawn out of the well and the parameters stop changing, it indicates that water is being drawn from the actual aquifer. After enough groundwater is purged and the parameters stabilize, containers are filled with the groundwater and sent to an Environmental Laboratory Approval Program accredited lab. The containers are provided by the lab conducting the tests and vary based on the contaminant that is being measured. The filled containers are carefully labeled with the location and time of the sample and are packed into coolers with ice for shipping. The ice limits changes to the contaminant concentration during the shipping process.

USACE follows quality control procedures to ensure accurate data. Duplicate samples are collected at ten percent of the locations. The duplicate samples are compared to initial samples to ensure the samples show a similar concentration. Samples of clean water that have been exposed to our equipment after decontamination are also collected to test the decontamination procedure and check for cross contamination.

Before moving to a new sampling location, any reusable equipment is decontaminated and cleaned. Single-use equipment such as the flexible tubing and gloves are disposed.
Groundwater testing is one way the Louisville District’s environmental program works to build a strong, sustainable environment for future generations.

Chick Lock

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