Water Quality Inquiry: Testing for Fecal Coliform in Sausal Creek Watershed


Throughout the 2017 – 2018 school year, Skyline Earth Team has been collecting and analyzing water quality data from around Sausal Creek Watershed.  The interns used La Motte test kits to monitor parameters such as pH, dissolved oxygen, and temperature.  However, the question at the heart of all of this hard work remained unanswered: does pet waste negatively affect water quality in Dimond Park? To help answer this, the team turned to Ametek Laboratories in Fremont, California.

Water samples were collected from four sites in the watershed: Dimond Park by the playground, Dimond Canyon adjacent to the foot trail, an access point on Scout Road, and the end of Joaquin Miller Court.  These samples were taken to Aemtek’s lab, and within a few days the team had their results.

Screen Shot 2018-06-06 at 1.40.43 PM

This new data confirmed the team’s hypothesis, which inferred that fecal coliform levels would be highest in Dimond Canyon where off-leash dog traffic is highest.  The team was not surprised that the results from the microbiological analysis showed this, or that Dimond Park, which is also a common place to find dogs, showed high levels too. Further, readings at Scout Road were lower which aligns with limited foot traffic but high levels of runoff from the many nearby backyards that drain into the site.  Finally, Joaquin Miller Court, which is more isolated and less developed than the other sites, showed significantly lower levels of fecal coliform contamination.

Overall, all readings were higher than safe recreational levels of fecal coliform, which are set at 200 CFU/ 100 mL. This data acted as further motivation to the team, who feel even more strongly that their work matters and that there is plenty of room for improvement in educating and engaging the public in and around Dimond Park.

Posted By: