Widespread Contamination of Drinking Water from the East Poplar Oil Field in Montana

A new report from the U.S. Geological Survey (USGS) documents serious drinking water contamination caused by oil production in Montana. This is the latest report from the USGS in an ongoing investigation of groundwater contamination in and near the East Poplar oil field.

Researchers found that almost 18 square miles of the shallow aquifer in the study area is contaminated with brine (also known as “produced water”) that is co-produced with oil. Produced water can be many times saltier than seawater and may also contain hydrocarbons, heavy metals, and naturally occurring radioactive material.

These shallow aquifers are the only source of drinking water in the area. The contamination has impacted both private drinking water wells and public water supply wells for the city of Poplar. All told, the USGS estimates that anywhere from 15-37 billion gallons of groundwater is contaminated with brine, compromising the groundwater supplies of about 3,000 people. As a result, the city of Poplar, headquarters of the Fort Peck Tribal government, had to build a pipeline to bring in drinking water from the Missouri River.

Oil production from the East Poplar oil field has been occurring for over 50 years. USGS researchers found that concerns about groundwater contamination were documented going back to the 1950s and contamination was actively occurring at least as late as 2001. Possible sources of contamination identified in the report include pits, pipelines, storage tanks, production wells, and brine disposal wells. However, researchers found that it is often not possible to pinpoint a single source, “…because several features commonly are co-located.” The contaminated plumes of water have been migrating over time, spreading the contamination.

Contamination of groundwater with brine is one of the most commonly cited environmental impacts of oil and gas production. This type of contamination can be extremely financially and technologically difficult to remediate, if not impossible.

The shoddy practices and lax oversight that led to the pollution of the drinking water of thousands of people cannot be allowed to continue. Oil and gas resources must be more responsibly developed, in ways that respect human life and the environment. The price of oil cannot be the loss of clean drinking water.