Water Quality in Stormwater Retention Ponds on UWB Campus Rick Vos

I would like to thank the following people for their valuable assistance on this project: Dr. Dan Jaffe John Hawthorne Joel Pothoff of UWB Physical Plant Hal Hoffman

Historical Data Impervious surface area in the North Creek Basin while hard to measure, has increased from an estimated 26.4% in 1996 (May 1997) to roughly 49% today. (Kerwin 2001) There has been a general increase in temperature and conductivity since (King County WLRD 2001) Only 23% of land in North Creek Basin remains forested.(Kerwin 2001)

Objective: To determine the water quality discharged from UWB campus into North Creek by measuring N0 3, PO 4, pH and conductivity in retention ponds. Compare values with historical data from North Creek.

GIS 2000 UWB Sampling Locations

Experimental Method: Phosphate and Nitrate were measured using Hach DR/2010 Portable Data Logging Spectrometer with Hach PhosVer® 3 Phosphate Reagent and NitraVer ® 5 Nitrate Reagent AccuVac® ampoules. Cole-Palmer Basic Conductivity Meter model # pH measured using an Oakton Phtestr®

Quality Assurance Known standard solutions were prepared for both nitrate (NO 3 - ) and phosphate (PO 4 ). Prior to each test a sample blank was prepared and used for zeroing and a standard sample was used to check DR/2020. A 147 µ S standard was prepared for calibration of the Cole-Palmer Conductivity meter. Meter was calibrated every 40 hours. The Oakton pH tester was calibrated using a 7.0 buffer solution weekly.

What does this mean? –Nitrate levels are lower in ponds –Phosphate levels are generally lower in ponds than North Creek –pH levels have exceeded required WAC a at all sampling sites.

Input flow to Sampling Sites on UWB Campus

In Conclusion