Frequently Asked Questions (FAQ)
Stormwater Managers
Many Cities, Counties and States are impacted by the
new regulations from the EPA "Clean
Water Act".
Some communities have reacted more quickly than others, and some are just getting
started, but all must become compliant with the new regulations. (See the
General Information page to get a better
understanding of the EPA requirements.) Also, see the
Stormwater Page on what is
required from each individual state. The use of pervious concrete pavements for
stormwater management can also help a Developer acquire credits toward
LEED Certification.
This page also contains Sections on: Stormwater Managers and Magruder Construction. (Click on your back-button to return to this list.)
The picture above shows one solution of dealing with on-site stormwater. All the stormwater runoff generated by an impervious pavement (asphalt) is channeled onto a discharge area of Pervious Concrete pavement with a layer of clean gravel directly below the pavement. In this design all the pavements are sloped to channel the stormwater to the storm drain in the curb. However, the water never actually gets to the drain. It is absorbed into the Pervious Concrete pavement, and is stored in the layer of clean gravel below the pavement. The water is eventually discharged by being absorbed into the soil below the layer of gravel. (This design is generally not recommended as the best use of Pervious Concrete Pavements. In this project all the pavements are "sloped". A better design would have been to have the entire parking lot constructed flat, and not used asphalt at all. See the Dual-Use concept. This could have eliminated the drainage structures altogether.)
Magruder Construction is turning gray concrete into green parking lots.
Stormwater Managers make the decisions as to the methods and materials that are allowed to be used in the development of properties that they feel will benefit the people in their jurisdictions. These methods and materials have become known as the "Best Management Practice" in complying with the EPA rulings. In order for Stormwater Managers to become familiar with the benefits of using Pervious Concrete they must first become knowledgeable about the material and how it can be used. The information contained on this Web site can help Stormwater Managers and Specifiers create a knowledge base on the product and its application. The Stormwater Manager, or Specifier, may want to review the section on Details and Specifications to get a better overview of the product and its applications. (See the Dual-Use Concept on the Engineers Page). The design and construction details for the dual-use system have been derived from the NIBS - Federal Green Construction Guide for Specifiers and the EPA Web Site "Porous Pavement".
Site Development costs, using the Dual-Use System, are generally reduced to less than half of the costs of asphalt pavements and associated stormwater infrastructures and retention-pond (land costs) for commercial developments.
Note: Pervious Concrete is not a proprietary product. No person or company owns the rights of distribution to the product, or its application. The material is typically sold, and carried to the jobsite, by a local Ready-Mix Concrete supplier. As a result, no one company is responsible for "advertising" the product. The National Ready Mixed Concrete Association (NRMCA) is one of the primary distributors of information on the product and its application. (See the section on Testing on the Details and Specifications Page.)
It may be in the best interest of the Owner/Developer to select a Sole Source Contractor to help in the design and development, as well as the construction of the project. (See the Sole Source Justification page.)
Important: Because of the lack of standardized test for quality control and acceptance of Pervious Concrete, it is critical that whoever is making the decisions for acceptance of both the fresh concrete, and the finished pavement, that they are qualified to do so. The decision-maker must have adequate knowledge and experience to recognize the essential properties of Pervious Concrete, and know how to make field-adjustments. (Note: Both the NRMCA, and the National Institute of Building Sciences, recognize that only NRMCA Certified "Craftsmen" have the 1500-3000 hours of experience necessary as a basis of qualification.)
Magruder Construction has helped many Stormwater Managers in their quest to gain an understanding of Pervious Concrete, and its applications (to include LEED Certifications). Contact Don Wade, Program Manager, and NRMCA Certified Craftsman.