Picture this scenario: It’s raining as you drive home. You splash through a puddle in the gutter next to a construction site. Murky water sprays all over the windshield and flows down a storm drain. That water has a name: stormwater runoff. Have you ever considered what’s actually in that water?
Stormwater runoff is a destructive result of industry and urbanization. Construction sites are no stranger to soil degradation and pollution. With plenty of heavy chemicals and wastewater production, runoff is a significant issue for any site. Fortunately, best management practices help reduce the abundance of runoff danger found at many construction sites.
Thus, with the above in mind, here are three effective strategies for managing stormwater runoff at construction sites. First, however, let’s discuss the risks of stormwater runoff in more detail.
The Dangers of Stormwater Runoff
Stormwater runoff isn’t merely rainwater. As it flows down roads and sidewalks, fallen rain collects everything it travels over. This includes oil, detergents, medical waste, and food scraps—you name it.
Higher percentages of impervious surfaces, like roads and roofs, force rainwater to flow and collect debris. Without the natural absorption and filtering of the land, this water will flow until it enters a waterway.
Stormwater runoff is high in toxins, pathogens, and nutrients like phosphorus and nitrogen. If that enters a waterway, pure pollution poisons the environment.
Awareness of this problem is the first step for any construction site. Without best management practices, construction sites must navigate hazardous waters independently (pun intended). Failure to contain runoff water leads to fines or even site closures. Jail time is another possibility, should construction pollution cause environmental damage.
Starting a best management practice (BMP) shouldn’t begin from scratch, though. Site supervisors should follow existing BMPs, and adapt them to the specific site needs. Doing so provides many production and safety benefits for the site and the workers.
Benefits of a Stormwater BMP
A plan in place allows for active management. BMPs create a guide for all workers to follow, and with the hazards of stormwater runoff, there is no room for “good enough.” Indeed, best management practices enshrine the minimum standards into the site’s same rules.
Because of stormwater runoff’s danger, every site must maintain preparedness for all potential issues. Just as all employees must know site safety rules, they must also understand runoff procedures. These include:
Site entrance cleaning: Clean tires and other equipment of site contamination before leaving the site.
Functional testing and monitoring: Designate stormwater officers to ensure preventative measures, especially in a storm-prone area.
On-going training: Keep employees educated on runoff, pollution, and even local ordinances to follow.
Stormwater BMPs turn these necessities into workable actions. Forethought preparation can manage and curb construction site runoff issues. Here are three BMPs that work across a range of sites.
Three BMPs That Work
Best management practices will vary from site to site, but the following three highlight the main focus and importance of runoff control:
Vegetated Filter Strips: Linear BMP
Protected Areas and Reducing Site Disturbance
Stormwater wetlands are like infiltration or retention basins. They collect and filter runoff as it enters the ground. Wetlands also work to control erosion through expansive subsurface root systems. These wetlands also become thriving ecosystems of native flora and fauna.
Constructed wetlands are unique BMPs, designed to divert and capture drainage at a specific area. Some find use on existing retention basins; others adapt the land to fulfill the site’s needs. Wetlands need adequate acreage (at least 25 acres). Plus, the ground must follow particular criteria, such as depth values and outflow paths.
Constructed wetlands can remove up to 80% of suspended solids when adequately implemented. Wetlands also filter out disruptive nutrients, dangerous metals, and harmful pathogens.
Vegetated filter strips act as filters between pollution and bodies of water. Known as linear BMP, these buffer strips use natural features such as soil and roots to filter runoff before entering clean water.
As linear BMPs, filter strips work best throughout the land. They are wide enough to filter the runoff but narrow enough to avoid impeding natural or construction resources. Like wetlands, these strips also become habitats for local plants and animals.
Filter strips find use in many areas of heavy pollution. Field-edge strips help farms reduce the number of nutrients that flow from a field. At construction sites, meanwhile, filter strips help keep protected adjacent areas safe.
Besides structure-based BMPs, construction firms also use non-structural practices. Often, these are proactive measures meant to avoid problems in the first place.
For example, municipalities can designate areas as protected. This forces sites to adapt their practices to avoid runoff contamination. Construction sites should work with the local government to promote safe water practices, highlighting the BMPs used to keep the local areas safe. This outreach helps to solidify the site’s commitment to runoff control.
A more active approach involves changes to construction site work habits. Stormwater runoff becomes less damaging by removing the pollutants in its path. Construction sites should thus disturb less topsoil and keep existing vegetation intact. This protects natural filters and erosion controls within the ground. And, with less contaminated topsoil in the runoff, there are fewer pollutants in the water.
Stormwater runoff is hazardous and destructive. Combined with a construction site’s loose soils and industrial chemicals, this runoff causes a lot of damage to the land. Construction site best management practices can remedy these problems. Indeed, with comprehensive planning and constant monitoring, a place can ensure that its storm and wastewater stay secure.