Hurricane Harvey brought heavy rain and destructive flooding to the Houston, Texas area over the weekend and into Monday, causing many to wonder what the implications will be for water quality. Some feared that the drinking water supply would be contaminated, as water treatment facilities struggled to keep up with the deluge.

Here is how severe weather events, like Hurricane Harvey, can affect water and wastewater treatment and a timeline of water quality events in Houston so far:

How will Hurricane Harvey affect drinking water quality in Houston?

Flood water can create health risks by damaging water supply systems, contaminating drinking water, and disrupting transport. Among these risks, drinking water contamination is often the top concern. Drinking water contamination can occur due to flood water mixing with surface water, groundwater, or water distribution supplies. Because flood water is uncontrolled, it can pick up bacteria, sewage, agricultural waste, and other dangerous constituents. This has adverse effects on sanitation and hygiene and may lead to the spread of waterborne illness.

According to the Centers for Disease Control and Prevention (CDC), a widespread outbreak of an infectious disease is very unlikely in the United States, even following a hurricane. Nonetheless, the Department of Health and Human Services will set up tracking systems after a hurricane to identify and address the spread of disease, should it become an issue.

Timeline of water quality events in Houston:

Friday, August 25 (9:45pm): Hurricane Harvey makes landfall near Corpus Christi, TX.

Saturday, August 26: A boil water notice is issued for Victoria County. A previous notice was issued Friday for Corpus Christi, nearby where Harvey first made landfall. Residents of affected areas can boil water to destroy harmful pathogens.

Sunday, August 27 (10:06am): Houston Office of Emergency Management announces no plans to shut off water, responding to rumors and concern from the public.

Sunday, August 27 (10:11am): Houston Mayor Sylvester Turner reassures citizens that water treatment plants are keeping up with 100% of treatment needs and water is safe.

Monday, August 28 (8:09am): Houston Mayor Sylvester Turner announces that water influx to Lake Houston caused a water treatment plant Northeast of the city to go underwater.

Monday, August 28 (11:55am): Sylvester Turner announces that drinking water supply is safe and plants are meeting treatment needs. However, if treatment capacity drops below 20%, boiling of drinking water will be advised.

Monday, August 28 (12:05pm): Houston Public Works announces that despite submersion of one water treatment plant, the drinking water supply remains safe. However, the public is encouraged to limit water usage as much as possible.

Tuesday, August 29:  Parts of Houston, including Utility District 6 in Harris County, the Lake Forest Utility, and Montgomery County’s Woodbranch Village, are issued boil water advisories. Residents should boil water before drinking to ensure the destruction of possibly harmful contaminants.

Thursday, August 31:  Pump failures in Beaumount, TX cause complete shut down of drinking water systems in the area. Officials are still uncertain of when safe drinking water will become available again.

Thursday, August 31 (1:48pm):  The EPA releases an official statement on water quality status and relief efforts in flood impacted areas in Texas.

What to do if you’re concerned about drinking water quality after Hurricane Harvey:

  • Follow Houston Public Works (@HoustonPWE), Sylvester Turner (@SylvesterTurner), and Houston Office of Emergency Management (@HoustonOEM) for more updates
  • If your water is discolored, it is likely due to iron, a result of aging pipes. While this is an inconvenience, iron is not a health concern
  • Conserve water as much as possible to relieve the burden on Houston area water treatment facilities
  • If you are still concerned, you can boil drinking water as an added precaution. A list of Boil Water Notices and Boil Water Lifts is available on Aqua America’s Texas state page.