Stormwater—the runoff from rain, snow, sleet and hail—is inherently polluted with the contaminants found on the roads and other surfaces from which it, well, runs off. Stormwater runoff is a major source of pollution to our waterways; in fact, the United States Environmental Protection Agency (EPA) names polluted runoff as one of the biggest threats to our water supply.
As environmentalists push for better control of stormwater, budgetary concerns seem to be preventing more cities from adopting projects that facilitate compliance with the Clean Water Act, which outlines the structure for regulating the discharge of pollutants into US waters. Although green infrastructure isn’t currently being incorporated within all the major cities across the nation, efforts to improve the current landscape are increasing.
Reducing Runoff with Bioswales
Bioswales are one way cities are working to reduce the environmental impact of stormwater. A bioswale is a type of landscaping drainage system designed to collect and store stormwater runoff to help reduce pollution as the water moves downstream.
Bioswale Design and Construction
A bioswale comprises of a swaled drainage course with gently sloped sides (generally no greater than five to six percent). The swale is typically filled with vegetation, compost and/or riprap, which helps to hold the ground water and delay its release into the environment. Bioswales are the most effective type of green infrastructure facility in slowing runoff velocity and cleansing water while recharging the underlying groundwater table. They have flexible siting requirements, allowing them to be integrated with medians, cul-de-sacs, bulb outs and other public space or traffic-calming strategies.
As bioswales gain traction as a means of reducing the effects of stormwater runoff and preserving the quality of our waterways, it is imperative that the highest quality materials are used to get the job done right. While we may not be experts in the actual construction of a bioswale, we are experts in getting you the highest quality heavy-duty liners and geotextiles at the best price. Here are the top liners you’ll want for your bioswale installation.
Best Bioswale Liners
Facility liners are used for groundwater quality preservation as well as for steep slope or building protection. A waterproof liner can reduce stormwater pollution from reaching ground water, prevent infiltration where underflow could cause problems with steep slopes or nearby structures, and maintain wet conditions to nurture wetland vegetation.
High Density Polyethylene (HDPE) is the most commonly-used geomembrane due to its low cost, high availability and durability. Its chemical and UV resistance makes it an excellent liner for bioswales. Custom-fabricated HDPE geomembrane liners are available in 12 mil to 100 mil.
Low Linear Density Polyethylene (LLDPE) is the most flexible option for building your bioswale. These liners offer higher elongation properties than HDPE liners, which means higher tensile strength and better conformability. LLDPE is available in 12 mil to 60 mil.
Polyvinyl Chloride (PVC) has the ability to be solvent welded, taped or field-heat welded. The PVC compound includes fillers and plasticizers to reduce cost and UV inhibitors to extend outdoor service life. PVC is available in 10 mil to 60 mil.
Reinforced Polyethylene (RPE), also commonly referred to as Woven Coated Polyethylene (WCP), has the highest puncture and tear resistance of any poly liner. The material has a highly impermeable, UV- and abrasion-resistant coating that offers minimal thermal expansion and contraction. RPE/WCP is available in 9 mil to 40 mil.
Pipe boots are used to finish the job by closing off the end of the pipe that has penetrated the liner. This can be accomplished through a variety of techniques, including taping, welding and cementing. For the best solution for your project, consult your material supplier or contractor.
Best Bioswale Geotextiles
Geotextile filter fabrics are used in the underdrain system, at the bottom, sides and top of the engineered soil to prevent fine soil/sediment from scouring within the swale. Turf reinforcement mats are used for erosion protection to support vegetation on slopes.
Nonwoven geotextiles are often used for drainage, filtration and light separation between subsoils and rock riprap. The felt-like fabric is needle-punched to create a permeable material that offers excellent water flow properties, making non-woven geotextiles ideal for bioswales.
Woven geotextiles have strips of film woven together to create an impermeable material used for separation and reinforcement.
Choose a Top-Quality, Custom-Fabricated Liner or Geotextile
Since the purpose of a bioswale is the filtration of pollutants in stormwater, it is best to use a bioswale filter fabric that has been seamed in a factory-controlled environment with stringent quality assurance measures in place. Field seaming can be affected by various conditions on the job site, such as windy and rainy weather, blowing dust and debris, temperature variations and more.
Americover has been a source of custom-fabricated liners and geotextiles for more than 25 years. Leveraging our network of US-based manufacturers, we can have your material customized and fabricated within a week and delivered straight to your job site (note that lead times may vary during peak season).
To get started, send us your product specifications in the form below, and we’ll respond promptly with a quote.
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We offer special pricing, volume discounts, short lead times and a dedicated account manager who will work with you to get exactly what you need. If you would like to speak with a representative, contact us at 760-388-6294.
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As an Americover customer, you will receive the personalized support of a dedicated account manager to simplify the ordering process and ensure the best solution for every one of your projects. Our friendly, knowledgeable staff is here to answer your questions and fulfill orders Monday-Friday from 6 a.m. to 6:30 p.m. Pacific Standard Time. If you would like to speak with a representative, contact us at 760-388-6294.