Have You Noticed Them Yet

The North Carolina Division of Environment and Natural Resources, Division of Water Quality amended the 1987 Clean Water Act to incorporate new rules and regulations that are needed to protect the quality of our streams, lakes and rivers.  Understanding that as we build and create additional impervious surfaces, the natural filtering process of our soils and vegetation are negated and the need for that filtering process is increased with the additional pollution we create. We often don’t realize, or actually think about the pollution as we over fertilize our yards, and allow auto oil from parking surfaces to wash into our natural environment. Excess nitrogen and phosphorous as well as sediment and suspended solids are causing major problems in our natural eco systems. So the amendment was needed to take control and begin to clean what is polluted, and to refrain from allowing future pollution increases. First, with some restrictions, we are learning to collect and treat our rainfall, “storm water”.

Excess nitrogen and phosphorous as well as sediment and suspended solids are causing major problems in our natural eco-systems. So the amendment was needed to take control and begin to clean what is polluted, and to refrain from allowing future pollution increases. First, with some restrictions, we are learning to collect and treat our rainfall, “storm water”.

Our local governments have been mandated to develop storm water management programs that significantly reduce the amounts of nitrogen, phosphorous and total suspended solids prior to allowing its release back into the environment.  We are also controlling the way storm water is released, by controlling the post construction run-off storm flow to the pre-construction release rate.  Additionally, water must be dispersed at release as opposed to point concentrations. These new devices are being required on almost every form of new development from the latest Wal-Mart to the fast food restaurant, and even in most residential subdivisions or apartment complexes. 

What are the devices…?  You may have seen them and not even known what they are and why they are “where” they are. The types of storm water treatment devices are varied and in some ways puzzling to the layperson as to what they do and why we need them. There are both structural and non-structure methods for treating storm water.  Wet ponds, dry ponds, bioretention filters, grassed swales, sand filters and created wetlands. They sound almost exotic and are hard to imagine.  

To most engineers in North Carolina, these BMP’s (Best Management Practices) are new, and they most likely don’t fully understand how they are designed or more importantly, how they “should” function. In fact, most are not new, as many have been used in the Chesapeake Bay area of Maryland and Virginia for almost 30 years. If you are as old as I am you will recall the campaign to help clean up the bay which was successful and virtually saved the highly regarded lobster industry... There are some new devices but all of them go through periodic modifications and analysis in order to refine them and adapt them to special conditions or circumstances of a specific use.

We have been letting pollution harm our water resources for so long we don’t even realize we are doing it. Did you know that every time it rains excess nitrogen, phosphorous, and heavy metals from our atmosphere are washed into our streams and rivers?  I remember in the mid 60’s going with my brother for shad fishing on the Tar just below the old mill dam.  I never thought about the condition of the water, and we did eat a lot of fish.  We must drink the water, and wildlife and fish need clean aerobic water to survive.  I recall a fishing vacation trip and was told to not eat the fish at a specific lake in Person County due to high levels of mercury, and I remember the strange floating aerator we found one day when inspecting an old farm tract in Franklin County.  The ground water had leached hydrocarbons from a nearby (1/2 mile) gas station and the aerator was to evaporate the toxic hydrocarbon materials.  Incidentally, there were numerous “no smoking” signs nailed to the trees. 

Often when we speak to our clients and mention their “BMP”… we are confronted with a blank stare, obviously meaning they do not understand... in which case we clarify with… “Your storm water device”… as the blank expression continues we finally give in… “The big hole in back”.  Suddenly the light goes on and the picture is clear… “Oh that thing”.  I encourage you to look for BMP’s and to be very grateful that, finally, we are doing something that will make a big difference in the future of our environment.  So… we need this regulation, and it is working.  Many of the BMP’s you really will not know are there because they are either screened out of site, or so well blended into their surroundings that you can see them and not know what it is… Have you noticed them yet?

The author is a Rocky Mount native, the son of Dr. Leonard Harris, of the former Harris Conservatory of Music. Mr Harris has operated his successful Environmental Engineering firm since its inception in 1981.