Private water wells in Texas test positive for contamination after Harvey

Rural residents in flood areas should have their water wells tested before drinking the water, according to Texas A&M.

See aerial photos of extreme flooding following the storm less Sgt. Destry Riggs scans flooded areas during a search and rescue operation run by the 36th Combat Aviation Brigade of the Texas Army national Guard over areas hit by Tropical Storm Harvey on Friday, Sept. 1, 2017, north of Beaumont, Texas. Sgt. Destry Riggs scans flooded areas during a search and rescue operation run by the 36th Combat Aviation Brigade of the Texas Army national Guard over areas hit by Tropical Storm Harvey on Friday, Sept. 1, ... more Photo: Brett Coomer, Houston Chronicle Photo: Brett Coomer, Houston Chronicle Image 1 of / 117 Caption Close Private water wells in Texas test positive for contamination after Harvey 1 / 117 Back to Gallery

In the wake of Hurricane Harvey, nearly 60 percent of water samples from 50 private wells in Harris County tested positive for a bacteria sometimes found in feces, according to preliminary data released Wednesday.

The presence of total coliform, a bacteria sometimes found in feces but more commonly in soil and floodwater, was detected along with the more troubling E. coli. In Harris County, 18 percent of the samples revealed E. coli.

Experts warn that residents should not use water from their flooded well for cooking, bathing or drinking until it is tested because it can contain sewage from flooded wastewater treatment plants as well as manure, among other things.

COMPLETE COVERAGE: From before landfall to flooding after, read all about Hurricane Harvey

The data, released by Virginia Polytechnic Institute and State University, was analyzed after researchers there joined with Texas A&M University's AgriLife Extension Service to distribute free water sampling kits to residents who have private wells in counties impacted by Harvey.

The universities distributed 1,200 kits to residents, and received back 630 samples from 21 counties. All told, 47 percent of the samples tested positive for total coliform.

Total coliform tests often are used to determine the cleanliness of drinking water from private wells, but the presence of the bacteria does not mean those who consume the water will inevitably get sick, according to the Neilson Research Corporation, an Oregon-based company that conducts laboratory services for environmental projects, such as well water.

Total coliform's presence "indicates that a contamination pathway exists between a source of bacteria (surface water, septic system, animal waste, etc.) and the water supply," according to the corporation's website. "Disease-causing bacteria may use this pathway to enter the water supply."

More than 10 percent of wells, however, tested positive for E. coli, which suggests the water is contaminated with human or animal waste and is a better marker for the potential to cause disease, according to a Virginia Tech website.

In both cases, residents should decontaminate their wells, the website stated.

Virginia Tech noted Wednesday that these samples contain a mix of flooded and non-flooded drinking water wells, as well as non-drinking wells, so the actual rate of contamination associated with flooding could be higher or lower than the preliminary numbers show. They will be surveying well owners to better separate out the flooded drinking water wells.

In the days and weeks following Harvey's landfall Aug. 25, about 148 million gallons of raw sewage and industrial discharges spilled from wastewater treatment plants in counties impacted by the storm, according to the Texas Commission on Environmental Quality as of last week. More than 100 companies, including Valero Energy, Exxon Mobil and Arkema, had reported chemical spills as of last month, according to U.S. Coast Guard data.

The effort to inform Texans about the safety of their private water wells began in the weeks following Harvey, when Virginia Tech researcher Kelsey Pieper reached out to Texas A&M to offer assistance.

Pieper had led a similar effort to test for contaminants in flooded Louisiana wells a few years prior, she said, and was well acquainted with how to conduct the tests efficiently.

So with a $200,000 federal grant in hand, Pieper and her team shipped 1,200 water sampling kits to Texas. Those kits were then made available for free throughout September to residents with private wells in counties impacted by the storm.

Most of the testing was done in Virginia, said Drew Gholson, AgriLife Service program specialist and Texas Well Owner Network coordinator.

All individuals whose water came back positive for contaminants already have been informed, he said, and given information about how to decontaminate them. More information about this process can be found at the Texas A&M's website.

Diane Boellstorff, an AgriLife Extension water resource specialist, said Wednesday that residents generally were grateful to receive the news, which allowed them to take steps to ensure their drinking water was safe.

The most submitted water samples — 177 — came from Wharton County, where 50 percent tested positive for total coliform and 18 percent tested positive for E. coli, the data showed.

In Victoria County, researchers found that 42 percent of the 105 well water samples tested contained total coliform and 5 percent contained E. coli.

And in Liberty County, 63 percent of the 48 well water samples contained total coliform and 13 percent contained E. coli.

In about a half-dozen counties, no E. coli was detected, according to the data.

Virginia Tech researchers currently are gathering information from residents who submitted samples about how they receive information during flood events, Pieper said.

"We're asking them to complete a survey to understand where they look for information during disasters so we can better equip people during future events," she said. "We're asking them what information they want and where they want it available."

Pieper will use this information to create a comprehensive guide on how to communicate with water well owners during future natural disasters.

In the coming weeks, Gholson said Texas A&M will take up the testing reins as another round of sampling kits are handed out. He expects Texas researchers to hand out about 2,000 kits, though they are still waiting on federal funding to cover costs.

Information about when and where to pick up these additional kits is not yet available.

Alex Stuckey covers science and the environment for the Houston Chronicle. You can reach her at alex.stuckey@chron.com or Twitter.com/alexdstuckey.