Navigating New Jersey’s Complex Stormwater Management Requirements for Commercial Parking Lots
Commercial property owners and developers in New Jersey face increasingly stringent stormwater management requirements that can significantly impact parking lot construction and renovation projects. Understanding these regulations is crucial for ensuring compliance while protecting the environment and avoiding costly delays or penalties.
Understanding New Jersey’s Stormwater Management Framework
The New Jersey stormwater management rules were organized in 1983 and updated in 2004. In 2004 Governor James McGreevey signed into law two new stormwater rules. In March 2020, NJ Department of Environmental Protection (NJDEP) published the long-awaited revisions to the New Jersey Stormwater Management Rule (N.J.A.C. 7:8), which now requires the use of green infrastructure.
These regulations are comprehensive and apply to various impervious surfaces, with particular attention to commercial parking lots. Motor vehicle surfaces are defined as any pervious or impervious surface that is intended to be used by motor vehicles and/or aircraft, and is directly exposed to precipitation including, but not limited to, driveways, parking areas, parking garages, roads, racetracks, and runways.
Critical TSS Removal Requirements for Parking Lots
One of the most significant requirements for commercial parking lots is the Total Suspended Solids (TSS) removal standard. The amended rule requires these motor vehicle surfaces to have 80% total suspended solids (TSS) removal, in order to maintain water quality. These surfaces include standard pavement drive/parking areas and gravel and dirt drive/parking areas, according to the rule.
This requirement is triggered when specific thresholds are met. Stormwater management measures shall be designed to reduce the post-construction load of total suspended solids (TSS) in stormwater runoff by 80 percent of the anticipated load from the developed site, expressed as an annual average. Stormwater management measures shall only be required for water quality control if an additional one-quarter acre of impervious surface is being proposed on a development site.
Best Management Practices for Compliance
New Jersey recognizes several Best Management Practices (BMPs) that can help commercial parking lots achieve the required 80% TSS removal rate. Different BMPs have varying TSS removal rates: Bioretention 90%, Constructed Wetlands 90%, Forested Buffers 70%, Extended Detention Basin 40-60%, and Infiltration Structures.
It will be necessary at times to use a series of BMPs in a treatment train to achieve the required 80 percent TSS removal rate. In such cases, the total removal rate of the BMP treatment train is based on the removal rate of the second BMP applied to the fraction of the TSS load remaining after the runoff has passed through the first BMP.
Green Infrastructure Requirements
The 2020 updates to New Jersey’s stormwater rules emphasize green infrastructure solutions. On March 2, 2020, the New Jersey Department of Environmental Protection (NJDEP) formally adopted amendments to the state’s stormwater management rules (NJAC 7:8). The amendments seek to better protect water quality, quantity, and groundwater recharge through requiring the use of green infrastructure.
Green infrastructure approaches help manage stormwater at its source rather than simply collecting and channeling it away. In gray infrastructure systems, stormwater quickly flows off parking lots, roadways, rooftops, and other paved or hardened surfaces, carrying with it surface pollutants and litter, and emptying the polluted water into streams, rivers, and tidal waters. The relatively fast rate and high volume of water also causes bank erosion and flooding in and downstream of developed areas.
Municipal Compliance and Local Ordinances
New Jersey municipalities will need to comply with the new standards, as the NJ Stormwater Management Rule represents the minimum requirements for stormwater control ordinances. The law states that municipalities must update their ordinances by March 2, 2021. This means that commercial property owners must work with both state and local requirements when planning parking lot projects.
In Mercer County specifically, The Mercer County Planning Board plays a role in Stormwater Management in Mercer County by exercising its rights under the “County Planning Act” [N.J.S.A. 40:27] to review those site plans and subdivisions within Mercer County that will result in one or more acres of impervious surface, and/or are located along a County roadway, and/or will have an impact on County drainage facilities as determined by the County Engineer.
Working with Experienced Professionals
Given the complexity of these regulations, working with experienced paving contractors who understand stormwater management requirements is essential. For businesses in central New Jersey looking for professional Parking Lot Paving Mercer County, NJ, it’s crucial to choose contractors who are well-versed in both quality paving techniques and environmental compliance.
Located in Ringoes, NJ, servicing Lambertville, Pennington, Quakertown PA and all surrounding areas, since 2000, Productive Asphalt Paving has paved with lasting results, serving countless clients and projects. Productive Asphalt offers expert residential and commercial paving services in NJ and PA. From driveways to parking lots, we deliver durable, high-quality asphalt solutions. Productive Asphalt specializes in commercial services such as parking lots, line striping, grading, crack repair, and seal coating.
Planning for Long-term Success
Successful compliance with New Jersey’s stormwater management requirements requires careful planning from the project’s inception. Property owners should consider stormwater management as an integral part of their parking lot design rather than an afterthought. This approach not only ensures regulatory compliance but can also provide long-term benefits including reduced maintenance costs, improved property aesthetics, and enhanced environmental stewardship.
The regulations also require ongoing maintenance of stormwater management systems. Stormwater management measures share maintenance requirements which require regular inspection and cleaning, sediment and debris removal, and periodic replacement. In recognition of these needs and potential problems, the NJDEP Stormwater Management Rules require that a maintenance plan be developed for all stormwater management measures incorporated into the design.
By understanding these requirements and working with knowledgeable professionals, commercial property owners can successfully navigate New Jersey’s stormwater management regulations while creating functional, compliant, and environmentally responsible parking facilities.