Stormwater "Red Flags"
Many years ago, I interned for the local County Health Department and assisted them with water quality monitoring. The department monitored the water quality from twelve points along the rivers and streams in the county. Rain or shine, I headed out every Wednesday morning to collect samples. At each location, I pulled on the hip waders and walked a few meters from the shore to measure oxygen levels and collect a sample for the lab. Every week I plated petri dishes and counted E. coli colonies. Some days the water quality of the river was excellent and other days the bacteria levels (E. coli) in the river were dangerously high. What spiked the levels of bacteria levels in a body of water that moved over 30,000 cubic feet per minute? Rainfall, or more accurately: the pollution that the rainfall carried.
I later found out that some of the sampling locations were near animal farms, hence the E. coli. Water is often called the ‘universal solvent’ because more substances dissolve in water than in any other liquid. The Clean Water Act defines the term “pollutant” broadly.
“[A pollutant] includes any type of industrial, municipal, and agricultural waste discharged into water. Some examples are dredged soil, solid waste, incinerator residue, sewage, garbage, sewage sludge, munitions, chemical wastes, biological materials, radioactive materials, heat, wrecked or discarded equipment, rock, sand, cellar dirt and industrial, municipal, and agricultural waste.”
The Environmental Protection Agency and state governments work hard to protect waters through the implementation of the National Pollutant Discharge Elimination System (NPDES) permit program. Many industries obtain NPDES general stormwater permit coverage if they discharge into water of the United States. Sampling from a site’s discharge point(s) is an important part of the general NPDES permit. The data is compared with benchmark thresholds as an indicator of the effectiveness of the permit and stormwater control measures. Unlike an air permit, a stormwater sample result that exceeds one of the benchmark thresholds is often considered a “red flag” as opposed to a violation.
No one wants to have a “red flag” when they submit their stormwater results, but it may point to a problem with an exposed pollutant source at your site or a stormwater control measure that is not working correctly. Stormwater regulations protect our waters and, ultimately, protect our drinking water and health. As cliché as this sounds, our actions upstream impact our water downstream. Whether it’s general housekeeping at your facility or making sure a driver safely transfers material from your site, every action matters. Monitoring the exterior of your facility weekly is a great activity to ensure your site is not unintentionally polluting. Atypical events such as a leak or spill that was not cleaned up can be caught in time before the rainfall.
Remember that rivers, despite their size and capacity, can be significantly impacted by our actions. Let’s minimize the pollution the rain carries to keep the rivers healthy.
