The construction industry has undergone greater scrutiny in recent years, whether it’s from the Department of Housing or the EPA.
While this increased red tape has been associated with higher costs, they have also presented opportunities for improvement.
Through the use of strategic planning and stormwater Best Management Practices (BMPs), site operators can save significant money and avoid massive fines by creating a solid stormwater management plan.
Whether you’re developing an SWPPP or researching erosion control services, the type of stormwater BMPs you choose will be essential.
Certainly, while each state and municipality will differ in their rules, this guide will provide you with the essential knowledge to choose the right stormwater BMPs for any construction project.
The Importance of Stormwater BMPs
Between fertilizers, oils, paints, metals, and even sediment erosion that can wash away from an active construction zone, construction sites can be a significant source of pollution to surrounding ecosystems.
The Clean Water Act mandates that all construction sites that disturb up to 1 acre of land or discharge stormwater runoff into public source points must acquire an NPDES permit and develop an internal stormwater pollution prevention plan (SWPPP).
Stormwater BMPs are tasked with reducing pollution from an active work zone and managing runoff. Their main goals are to:
- Prevent Pollution: This includes water pollution from chemicals, as well as sediment runoff.
- Maintain Water Quality: Turbidity from sediment runoff can damage water quality and even lead to waterborne illness.
- Reduce Erosion: Erosion of nearby soil and land can lead to pollution and disrupt the local land ecosystem.
- Maintain Regulatory Compliance: Fines for stormwater runoff pollution can be significant and delay worksite progress.
- Prevent Flooding: Active stormwater runoff management also protects local ecosystems from flooding, including your own worksite.
- Conserve Vulnerable Resources: Certain aquatic species, such as trout or other fish, may require more hands-on management if they are considered vulnerable by location environmental authorities.
Assessing Your Project Needs
Before diving into the specifics, it’s important to note that each project will have its own stormwater BMPs that are tailored to their unique set of circumstances.
Some factors that will impact the choice of which stormwater BMP to use include:
- Site Assessment: A thorough site assessment of your work zone, the surrounding ecosystems, and its topography will help you identify potential sources of pollution and areas where active BMPs will be required.
- Project Size and Scope: The size of your project plays a significant role in determining the type of BMPs required. For example, smaller and shorter projects may only require non-structural BMPs, while larger projects may require extensive silt fencing, erosion control blankets, and more.
- Environmental Regulations: State and municipal regulations may require different BMPs for active and post-construction stormwater management.
Pre-Construction Planning: Questions You Should Ask
Phasing your construction activity and planning ahead reduces the number of BMPs required for each project.
During this stage, there are a number of questions you can ask that will help you determine which stormwater BMP is right for you.
- Which areas of my worksite are most vulnerable to erosion?
- Which water sources are more suitable to discharge my stormwater runoff?
- Are drainage areas suitable for a particular BMP? Will they be overwhelmed, and do they require additional support?
- Is there enough room to accommodate certain BMP designs, such as silt fence installation, retention ponds, etc.?
- Do you have the knowledge for retention pond maintenance and other specialized BMPs?
- Is there enough head that allows for stormwater to drain from certain sites properly?
- Is the soil amenable to biofiltration? Is the water table deep enough to allow for infiltration?
- Do discharge points require additional filtration? What protection can I offer to ponds, river beds, etc.?
- How often will I conduct inspections on my BMPs? Who will I train and task for inspections?
- What additional regulations does my state or municipality require? Do my proposed BMPs work for urban sites or require different calculations?
Types of Stormwater BMPs for Construction Sites
To familiarize yourself with the most common forms of stormwater BMPs used on a construction site, we’ve separated each of these BMPs into five categories for you to follow.
| BMPs | Purpose | Examples |
| Perimeter Preservation | Reduce the risk of uncontrolled runoff. |
|
| Slope Stabilization | Prevent erosion and reduce flooding risks. |
|
| Single-Area Protection | Increase area infiltration and reduce soil erosion. |
|
| Point Source Protection | Manage and filtrate runoff as it is discharged. |
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| Sediment Control | Filter out sediment before it is discharged. |
|
Perimeter Preservation
These BMPs are designed to protect the perimeter of sites, whether it’s around the tree line or shoreline.
Common BMPs
- Ripraps: Large rocks assembled around shorelines, most commonly rivers, oceans, and ponds.
- Silt Fencing: Large fencing constructed of geotextile fabric that helps filter out sediment and debris.
- Straw Wattles: Cylindrical straw bags that help filter out debris and sediment; commonly used on slopes and perimeters.
Slope Stabilization
Structural BMPs are designed to prevent slope erosion and reduce the velocity of runoff.
Common BMPs
- Underground Pipes: Diversionary pipes designed to channel runoff away from slopes.
- Erosion Control Matting: Geotextile fabric placed over soil that is designed to prevent erosion.
- Vegetated Swales: Contoured ditches filled with vegetation to increase infiltration and reduce runoff velocity.
Additional BMPs
- Silt Fencing
- Straw Wattles
Single-Area Protection
Many stormwater BMPs are designed to protect specific areas where the soil is vulnerable to erosion or opportunities exist for increased infiltration.
Common BMPs
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- Hydroseeding: Hydroseeding uses a slurry of organic compounds to promote quick revegetation of the soil.
- Infiltration Basins: Infiltration are small basins that allow the ground to collect and absorb stormwater before being deposited downstream.
- Porous Pavement: Porous pavement helps absorb water and infiltrate the soil underneath.
- Green Roofs: Green roofs help filter water from sediment and provide energy efficiency.
Additional BMPs
- Erosion Control Blankets
- Vegetated Swales
Point Source Protection
Certain stormwater BMPs can help protect and filter out nasty chemicals before they are discharged down storm drains or rivers.
- Oil-Water Separators: These filtration systems help separate viscous material from water being deposited down a storm drain.
- Storm Drain Inlet Protection: Small artificial barriers are placed around storm drains to help filter out heavy compounds.
- Catch Basin Inserts: Mesh filters are inserts in storm drains or pipes to provide additional filtration.
Sediment Control
Finally, sediment control BMPs are designed specifically to filter out sediment. One common example is a sediment or retention basin, which holds a large body of water, allowing site operators to scoop or filter out sediment before it is systematically discharged from the site.
Other common sediment controls include:
- Silt Fences
- Storm Drain Inlet Protection
- Sediment Filters
- Straw Wattles
- Ripraps
Additional Stormwater BMP Considerations
Before choosing which stormwater BMPs make the most sense for your worksite, consider the following factors:
- Consult with Experts: A third-party environmental consultant will help you create an SWPPP with stormwater BMPs that save you the most money and work the most effectively.
- Consider Multi-BMP Systems: Using a combination of structural and non-structural BMPs may be recommended depending on the size of your worksite.
- Regular Inspection and Maintenance: All stormwater BMPs require regular inspections and maintenance to ensure that they are working properly.
- Evaluate Costs: Consider the budget implications of your chosen BMPs. While environmentally friendly solutions are desirable, they must align with your project’s financial constraints.
- Monitor and Adjust: Depending on changing site plans, weather patterns, and results, you may need to adjust your BMPs.
Choosing the right stormwater BMPs is an integral part of any SWPPP. Now that you are armed with the right information, you can choose a stormwater BMP that best suits your needs and budget.
FAQs
What is the primary purpose of Stormwater BMPs?
Stormwater BMPs are designed to prevent pollution of surrounding ecosystems and erosion of the native soil.
Are there any financial incentives for using eco-friendly BMPs?
Many regions offer incentives and grants to encourage the use of eco-friendly BMPs. Check with local authorities for available programs.
Can I use multiple BMPs for the same project?
Yes, using a combination of BMPs can enhance stormwater management by addressing different aspects of runoff.
How often should Stormwater BMPs be inspected and maintained?
Regular inspections should be conducted every seven days or after a significant rainfall event to ensure every BMP is working properly.
What are the potential consequences of not using appropriate Stormwater BMPs?
Failure to use suitable Stormwater BMPs can lead to environmental pollution, regulatory fines, and damage to your project’s reputation.