Stormwater Management

Stormwater runoff is the most common way that nonpoint source pollution reaches local rivers, creeks and lakes. Stormwater will carry chemicals, nutrients, sediments and other forms of pollutants into local streams and other water bodies if the runoff is not absorbed by soil and vegetation. Therefore, a goal of stormwater management is to reduce the amount of pollutants being carried off into storm sewers and streams, as well as to reduce flooding.

In order to achieve the complete goal of stormwater management, a stormwater management system must be designed consisting of structural and non-structural elements. In 2004, The NJDEP adopted the Stormwater Management Rules N.J.A.C. 7:8 (the Rules) to specify stormwater management standards that are mandatory for projects defined as "major development". As a result of the Rules, the New Jersey Stormwater Best Management Practices (BMP) Manual was created consisting of 9 chapters providing guidance on how to address and comply with the Rules. The BMP Manual was developed by the New Jersey Department of Environmental Protection, in coordination with the New Jersey Department of Agriculture, the New Jersey Department of Community Affairs, the New Jersey Department of Transportation, municipal engineers, county engineers, consulting firms, contractors, and environmental organizations.

For projects subject to the Rules, the stormwater management system must successfully address, among other things, Stormwater Quality, Stormwater Quantity, and Groundwater Recharge. Stormwater quality is achieved by the reducing the average annual Total Suspended Solids (TSS) by 80%. Stormwater quantity is achieved by reducing the rates of run-off for post-development construction to predetermined degrees of reduction for three specific storm frequencies. Finally, Groundwater recharge is successfully achieved by

• demonstrating that 100% of the sites average annual pre-developed groundwater recharge volume can be maintained after development or
• by demonstrating that 100% of the difference between the site's pre-and post development 2-year run-off volume is infiltrated.

Complying with State, county and local requirements regarding stormwater management is a major consideration when evaluating the future success of the project. Our experience and knowledge permits us to properly understand the requirements of the Rules, successfully integrate the site's natural topography and groundcover with available stormwater management alternatives, correctly evaluate those potential alternatives, and design a stormwater management system or a series of systems to the achieve the goal of N.J.A.C. 7:8.