Management Program
Monitoring Results
This study will compare the water quality of runoff discharging from three types of pervious road surfaces, three types of amended bioswales, and conventional impervious asphalt.
All samples are analyzed by the City of Yakima Wastewater Treatment Laboratory for common urban stormwater pollutants including:
- Biological oxygen demand (BOD)
- Copper (Cu)
- Total suspended solids (TSS)
- Lead (Pb)
- Fecal coliform (FC)
- Zinc (Zn)
- Total petroleum hydrocarbons (TPH)
Mean Values of Previous Monitoring Events
November 18, 2010
April 5, 2011
July 13, 2011
October 6, 2011
November 7, 2011
April 18, 2012
November 8, 2012
The following graphs illustrate the lab results for each parameter listed above.
- % Swale = Percent of organic compost per swale
- Error bars are the standard deviation of the mean.
In a few cases, in particular with the 5% swales, the standard deviation of the mean exceeded the mean value because of high variability between sample events. The error bars for these mean values would have extended to less than zero, but these were stopped at zero since it is not possible for any of the data results to be less than zero.
Treatment Type |
Sites Numbers |
Permeable Pavers |
13 & 16 |
Porous Concrete |
14 & 18 |
Porous Asphalt |
15 & 17 |
10% Swale |
1 & 4 |
5% Swale |
2 & 5 |
0% Swale |
3 & 6 |
Impervious Surface |
7-12 |
= Urban Stormwater Median Pollutant Concentrations, National Stormwater Quality Database (NSQD)
(Pitt and Maestre, 2005)
