Stormwater Quality Monitoring

Water quality includes maintaining the physical, chemical, and biological integrity of water. Our monitoring programs use a comprehensive approach to identify local pollutants, monitor their levels, and use the data to target the development of Education and Public Involvement programs. By monitoring the stormwater we are able to learn which pollutants are contributing to the impairment of local waterbodies and how we can help keep stormwater clean.

As of 2015, the top five water quality issues of concern observed in our monitoring data are:

1. E. Coli
2. Dissolved Oxygen
3. Surfactants
4. Oil and Grease
5. Total Phosphorus

Wet Weather Monitoring 

Wet weather samples of stormwater are collected within 12 hours of a rain event and can tell us what pollutants are being washed into waterbodies when it rains. Currently, there are 13 wet weather monitoring stations and samples are tested for 14 different pollutants.

Wet Weather Monitoring Brochure

In-Stream Water Quality Monitoring 

In-stream water quality samples are a method for determining relatively constant pollutant levels in a waterbody. Samples are collected quarterly from 23 locations from a variety of sites, including impaired waterways. We are currently testing for 18 pollutants and 2 physical parameters.

Ambient Water Quality Monitoring Brochure

Sediment Monitoring

Instead of remaining suspended in the water column or being dissolved, some pollutants settle into the substrate—or the sediment at the to the bottom of a waterbody. Sediment samples are collected annually from 25 waterbodies to monitor pollutants at the bottom of waterbodies. The program currently tests for 9 pollutants and 2 physical parameters.

Sediment and Benthic Macroinvertebrate Monitoring Brochure

Benthic Macroinvertebrate Monitoring

Benthic macroinvertebrates are organisms that live at the bottom of waterbodies and in the riparian vegetation. Many of these organisms are very sensitive to pollution and monitoring this aspect of the water can give us an indication of the aquatic environment's biological health. Macroinvertebrate monitoring includes biodiversity (how many different species) and species richness (how many of each species).