Recreation:
E. coli Monitoring in Utah’s Waters

How can I reduce my risk of E. coli exposure?

To reduce potential health risks, you should assume all surface waters contain some E. coli whether or not it has been monitored or an advisory has been issued. In addition, there are some steps you can take to protect yourself while recreating in Utah’s waters.

  • Avoid swimming within 48 hours of a major storm
  • Avoid swimming if you have open cuts or wounds
  • Don’t swallow the water
  • Wash your hands before touching your mouth or eyes and before eating
  • Dispose of diapers properly
  • Pick up your dog’s waste and dispose of it properly
What is E. coli?

Escherichia coli or E. coli is a type of bacteria commonly found in the intestines and feces of healthy warm-blooded animals and humans.

Why should I care about E. coli?

While E. coli are not generally harmful themselves, their presence indicates that other pathogenic microorganisms might be present. E. coli is a good indicator of the presence of fecal contamination and possible disease-causing bacteria or viruses in water. Health officials use the presence of E. coli to determine if the public needs to be notified of a health risk.

How does E. coli affect individuals?

Most strains of E. coli are not dangerous to people. However, some can cause illness such as diarrhea, urinary tract infections, and other infections. Some infections are very mild, but others are severe or even life-threatening. More information on the health effects of E. coli can be found at the Center for Disease Control and Prevention.

Is the E. coli in lakes and streams the same as E. coli in food contamination?

Not necessarily. E. coli O157:H7 is a strain of E. coli which may be present in streams and lakes, but is most commonly spread through contaminated meats and vegetables and direct contact with infected people and animals. Waterborne transmission is possible through swimming and ingestion of water contaminated by E. coli. Additional information on E. coli O157:H7 can be found at the Center for Disease Control and Prevention.

How does E. coli get into lakes and reservoirs?

E. coli comes from human and animal waste from such sources as improper waste dumping, faulty septic tanks or sewer systems, domesticated animals—such as dogs and livestock, large concentrations of waterfowl and other wildlife, and stormwater runoff. Pollution of all kinds, including E. coli, are typically higher after rainstorms since water draining into streams and lakes travels over lawns, farm fields, sidewalks, and streets which may contribute sources of fecal contamination.

Are all waters tested for E. coli?

No. While the Utah Division of Water Quality (DWQ) has an E.coli monitoring program, it is not possible to test all waters in the state where people may recreate. Each recreation season from May through October, DWQ monitors many of Utah’s high priority recreation lakes and reservoirs. Rivers and streams are sampled following a targeted rotating basin schedule. For more information, visit DWQ’s E. coli Monitoring page.

Why is my lake (not) being tested for E. coli?

Ideal monitoring would involve collecting samples weekly at all locations throughout Utah, but monitoring resources are limited. Therefore, testing for potential E. coli contamination is focused on areas where people most frequently recreate. Each year, DWQ works with local health departments to prioritize highly recreated water bodies across Utah.

Less frequented lakes and reservoirs will be sampled in the coming years. Current monitoring plans include sampling at these targeted water bodies once a month from May through October. More frequent sampling may be required at specific lakes or reservoirs when the data suggests that E. coli densities are high.

What is my risk if there is an advisory?

Most strains of E. coli are not dangerous to people. However, some can cause illness such as diarrhea, urinary tract infections, and other infections. Some infections are very mild, but others are severe or even life-threatening. More information on the health effects of E. coli can be found at the Center for Disease Control and Prevention.

During an active E. coli advisory:

  • Do not ingest contaminated water
  • Do not swim or water ski
  • Wash hands after handling fish or contaminated water

While E. coli is an indicator of fecal contamination and may not be a direct cause of illness, the threshold of 409 most-probable number (MPN) per 100mL of water sample relates to a risk factor of 8 illnesses per 1,000 swimmers. As the value of the MPN increases above 409 MPN, the risk of illness if exposed to contaminated waters also increases.For more information, please visit DWQ’s E. coli Advisory page.

Where is an advisory posted?

E. coli advisories are issued by the local health department following guidance from DWQ. If an advisory is in place, signs will be posted at the lake/reservoir. Contact your local health department or visit DWQ’s E. coli advisory page for more information.

Can fish from the lake be contaminated because of E. coli?

Probably not. Because fish are not warm-blooded, E. coli cannot live in the fillets. However, the water covering the fish could contain E. coli, as well as the guts of the fish. Uncooked fish may well have E. coli contamination. Wash and cook the fish, and wash your hands after handling fish and lake water to reduce your risk.

What is being done to reduce the E. coli?

The primary objective of DWQs E. coli monitoring program is to monitor popular swimming and recreation areas to determine if they are high in E. coli. If problems are discovered through testing, additional monitoring will occur to identify areas that might contribute bacterial contamination. This is a difficult task due to the nature of E. coli pollution, since E. coli can come from many different sources and can be spread throughout a watershed.

Once the sources are known, field investigations can assist scientists and managers to identify problem areas and develop strategies to reduce pollution. While broken sewer lines or faulty septic systems can be difficult to find and repair, some sources can be corrected using common sense and care to reduce pollution. Often, this can include simple measures to prevent human or animal waste from being introduced into our waterways.