Water Quality Monitoring

The Creeks Division has received numerous grants for water quality improvement and restoration projects. Most grants require water quality monitoring as a condition of approval. The Creeks Division conducts all required grant monitoring on a timely basis.

The City’s NPDES Permit requires substantial water quality monitoring and reporting. The current NPDES Permit focuses on weekly indicator bacteria monitoring, toxicity testing, and the quantification of pollutant loads reduced by water quality improvement projects. The Creeks Division conducts all permit-required monitoring and reporting on a timely basis.

Routine watershed assessment includes weekly and monthly sampling at key points in the watersheds and focuses on measuring indicator bacteria and field parameters such as temperature and dissolved oxygen. Additionally, annual bioassessment sampling is conducted in spring. Bioassessment involves an ecological assessment of habitat and water quality by examining which aquatic organisms are present in our creeks.

Storm sampling is conducted in support of specific research questions. In prior years, sampling was targeted at identifying the pollutants of greatest concern to aquatic organisms. In recent years, storm sampling has targeted project performance and pesticide pollution in creeks and estuaries. Current storm sampling involves assessing project performance, quantifying microplastic pollution, and microbial source tracking to understand indicator bacteria pollution.

Project assessments include collecting and analyzing water quality data before and after projects are implemented. Data is collected upstream and downstream of the potential project sites, including data on indicator bacteria, habitat quality, and chemical pollutants.

The goals of sampling at restoration and water quality improvement project sites are to attain at least one year of comprehensive baseline water quality data for creeks at restoration sites prior to project construction, to identify problem pollutants, and to track the effectiveness of the projects in reducing problem pollutants.

One of the main challenges to improving water quality is that the sources of bacterial pollution are often not known. Although high levels of indicator bacteria suggest that human waste may be present, there are many other sources of indicator bacteria, including those that are native to soils.

The Creeks Division participates in scientific research that uses DNA-based techniques to examine whether indicator bacteria come from of human waste or animal waste. Once the type of waste is identified, DNA-based tools are also used to locate routes of contamination, and to eliminate the contamination before it reaches the creeks and ocean.