The U.S. Environmental Protection Agency (EPA) has announced that it will propose and take final action by November 2012 on a first-time national rule that would control stormwater discharges from newly developed, previously developed and redeveloped sites. EPA plans to propose a regulation to strengthen the national stormwater permit program, including, at a minimum, new design or performance standards to control post-construction stormwater discharges from developed sites under the authority of section 402(p) of the Clean Water Act. According to EPA, the Agency is gearing up to revise the National Pollutant Discharge Elimination System (NPDES) regulations to respond to a 2008 National Research Council (NRC) report that calls for “radical changes” to EPA’s stormwater control program. The report, Urban Stormwater Management in the United States, concludes that the lack of requirement for post-construction stormwater controls in the construction industry’s general permit is a “glaring shortcoming.”
In order to prepare for these pending stormwater regulations, property owners may need to evaluate whether maintenance and rehabilitation of the infrastructure of their facilities is needed to achieve the requirements of the regulations. The monitoring and maintenance of property infrastructure is critical to ensure it functions as designed and meets or exceeds its design life. The specific aspects of site infrastructure that can impact stormwater discharge quality and can be addressed during a property infrastructure assessment include:
Stormwater Facilities: Inspection and maintenance of stormwater facilities ensures that stormwater infrastructure is functioning in accordance with the design and regulatory permitting requirements. Maintaining properly functioning stormwater management facilities results in improved water quality, reduced stormwater runoff, and reduced nonpoint source pollution to surface waters (rivers, streams, ponds, lakes, etc.) within the community. Improperly maintained facilities not only decrease efficiency and pollutant removal rates, but can also create environmental hazards such as flooding and contamination to surface waters. Further, the deterioration of stormwater facilities can result in the distress of other site infrastructure features (e.g., sinkhole formation beneath pavement).
Pavement: Either the Pavement Surface Evaluation and Rating (PASER) or ASTM Pavement Condition Index (PCI) systems can be used to assess pavement conditions. Both provide an easy to understand comparative evaluation that will allow you to make cost-effective decisions relative to the maintenance and rehabilitation of the existing pavement. Additionally, a subsurface exploration can assess the as-built conditions and thickness of the existing pavement components and the pavement subgrade materials. Once the analysis is complete, a site pavement rehabilitation plan can then be prepared inclusive of details and bid documents for use during maintenance and rehabilitation. A wide variety of rehabilitation/maintenance techniques can be incorporated to maximize the cost-efficiency of the rehabilitation, including overlays, sealants, joint repairs and subgrade improvements.
Overall Site Conditions: Site modifications, changes to surface drainage patterns, offsite development and/or other factors may impact the quality of stormwater discharges from the property. A site condition review will evaluate slopes and embankments, sidewalks and crosswalks, pavement markings and traffic signage, surface drainage controls, slope benches and drainage outlets.
Ponds and Natural Enhancement Areas: Not to be overlooked is the natural environment of existing pond and landscape areas. Consider beautifying existing pond areas by removing cattails and invasive species and replacing them with native species and attractive wildflowers that will improve the biodiversity of an existing development. These improvements will enhance water quality and reduce the amount of erosion generated over time. This sustainable approach to stormwater management can turn a functional asset into an amenity.
While assessing the site infrastructure that can directly impact stormwater discharge quality, other site features can be assessed including:
Parking Lots:Reviewing existing parking lot layouts allows the evaluation of the efficiency of site parking areas, internal access roads and external driveways. Pedestrian and vehicular safety can be assessed as well. Pavement rehabilitation/maintenance provides an opportunity for property owners to upgrade the site parking lot and roadway layouts in an economical manner to address changes in site use to meet local zoning requirements, state Department of Transportation requirements, and/or Americans with Disabilities Act (ADA) criteria.
Site Utilities: Underground utility infrastructure can be located using a variety of geophysical technologies. The location of utility infrastructure is an important element of property maintenance; particularly in the absence of “as built” information, or if site expansions and/or modifications are proposed.
It’s important that property owners take time to fully inspect infrastructure for signs of damage due to aging, natural elements or harsh weather. Further, an annual infrastructure evaluation allows you to maximize efficiency of your resources. The monitoring and maintenance of property infrastructure is critical to ensure it functions as designed and meets or exceeds the design life.
To learn more about how your infrastructure can impact stormwater discharges from your site, or assist with infrastructure maintenance and rehabilitation needs, contact Mike Sheleheda, P.E. at (800) 899-3610 or MSheleheda@cecinc.com, or Rick Celender, C.E.T., CPESC, CPSWQ at (800) 365-2324 or RCelender@cecinc.com).