Do agencies use DNA testing to identify sources of fecal bacteria?

Sometimes, but not on a routine basis. Several misconceptions exist about using DNA testing, or Microbial Source Tracking (MST), to find the source of fecal pollution. One mistaken belief is that a single water sample can point out which specific person or animal is causing the pollution. Current science is not capable of identifying all sources of fecal bacteria in a water sample. Analysis looks for genetic markers for certain species, but we do not have markers for all species. Even if a lab develops a marker for a certain species, not all individuals of that species may carry the marker. MST strategies rely on establishing patterns based on multiple samples taken over time from specific sampling locations. A limited number of labs are qualified to conduct MST analysis and costs are high. Past MST studies in Whatcom County’s Drayton Harbor watershed and in Skagit County’s Samish watershed confirmed already suspected fecal pollution from humans and from ruminants (cows, horses, and sheep) among other unidentified sources. Fecal pollution to water from human, livestock, and pet sources is preventable. Finding and fixing those sources provide the opportunity for improving water quality to healthy conditions.

Show All Answers

1. How does fecal bacteria pollution get into water?
2. Why do we test for indicator bacteria instead of pathogens to determine if water is healthy?
3. Are wastewater treatment plants polluting the Nooksack River?
4. Is pollution from the Lummi Reservation causing high fecal coliform bacteria levels in Portage Bay?
5. Can wildlife contribute to high fecal bacteria levels in water?
6. Do agencies use DNA testing to identify sources of fecal bacteria?
7. What can I do about fecal bacteria pollution?
8. Who can help me prevent manure-related pollution?
9. Who can help me prevent pollution from my septic system?
10. Has the state’s surface water quality standard for bacteria changed recently?
11. How does Whatcom County decide when to sample water?
12. Can wood waste (decomposing wood or vegetation) contribute to bacteria pollution?
13. Can Klebsiella be harmful to people?
14. Who enforces codes and laws related to protecting water quality?
15. What does “non-regulatory technical assistance” mean?