Rohnert Park Nutrient Loading

Project Description: Is Rohnert Park contributing to nutrient loading into the Laguna de Santa Rosa?
  • How do levels of ammonia, nitrate, nitrite, TKN, nitrogen, orthophosphate, and phosphorus change in Copeland Creek in different regions (rural, residential, downstream of agricultural runoff, and at the Laguna)?
  • How to these levels change over time?
  • What effect does the first major rainfall of the season have on these levels?

Duration: Spring 2014 - ongoing

Type of Educational Activities: Service-learning, internship

Project Faculty: Jackie Guilford (ENSP)

Partners/Funding: Jeff Church (Sonoma County Water Agency); The Digital/Critical Cohort

Participating Courses:

  • ENSP 450 Sustainable Water Technology and Toxicology - 16 students
  • ENSP 499 Independent Research - 2 students

Sampling Locations

  • Copeland Creek at the SSU Environmental Technology Center
  • Copeland Creek at Commerce Blvd
  • Copeland Creek at Laguna Road (behind Petsmart) 
  • Laguna de Santa Rosa at Stony Point Road 

Sampling Schedule - Students sampled at all four sites on September 5, October 2, November 7, and December 10. First flush was sampled on November 17, the day after the first significant rainfall of the season. January and February samplings are planned.

Target Variables and Protocols - Students used LabQuest units and sensors to measure:

  • Temperature
  • pH
  • total dissoved oxygen

Additionally, the following nutrients will be submitted to a certified laboratory (Alpha Analytical Laboratories, Inc) for testing:

    • Ammonia as N  
    • Ammonia as N Unionized
    • Nitrate as N
    • Nitrite as N
    • TKN
    • Nitrogen Total
    • Orthophosphate             
    • Phosphorus Total     

Quality Assurance and Control (also see data disclaimer) - Students met with SCWA staff Jeff Church on September 5, 2014 for training in how to take a water sample. Jackie Guilford provided training on the use of the LabQuest units and sensors. and initial sampling. All water samples are tested by a certified laboratory.

Data: (see data disclaimer)


  • Investigation of the Impact of the City of Rohnert Park on Nutrient Levels in Copeland Creek. Amanda Appel, Jeff Church, Felix Desperrier, Pauline Espinoza, Paul George, Roman Gomez, Maya Hoholick, Kara Kelly, Christopher March, Justine Minyard, Thanh Quach, Justin Regester, Cameron , Revere, Taylor Swain, Daniel Tehrani, Byron Williams, and Ashleen Rai (Advisor: Jacquelyn Guilford). Appel et al. 2015 (0.7 Mb)
  • Water Sampling Results in the Laguna Watershed. Kara Kelly, Cameron Revere, Chris March and Amanda Appel. (Advisor: Jackie Gulford). ESNP 450 Website

Drainage Maps of Copeland Creek Watershed: