Background

Management of stormwater runoff is a topic receiving considerable interest. Many municipalities are experiencing severe flooding problems due to inadequate stormwater handling systems and, along with industries, are facing regulations controlling the discharge of stormwater.

The U. S. Environmental Protection Agency has promulgated regulations to permit and control stormwater discharges associated with industrial activity. Industrial activity includes manufacturing facilities, landfills, wastewater treatment plants, airports, transportation facilities, and other such sites. Under 40 CFR 122.26, stormwater discharges from such industrial activities must obtain a National Pollutant Discharge Elimination System (NPDES) permit.

Stormwater Management

Proper stormwater management requires complete understanding of the hydraulics of drainage basins and stormwater collection systems. We utilize a systematic approach to stormwater basin studies that allows us to understand the existing system and predict the impact of various storm events on the drainage characteristics of the basin. The first step in such a study is inventory and evaluation of existing stormwater drainage structures and systems. Once this is accomplished, the entire drainage basin is studied using sophisticated computer models to predict the response of the drainage basin to various storm events. This model can predict problem areas, pointing out where drainage improvements are necessary. Using this data, we evaluate alternative solutions to these drainage problems, presenting recommendations for such improvements. This is done in a Stormwater Drainage Improvement Plan (SDIP). The SDIP contains a description of recommended drainage improvements, along with estimated construction costs for these improvements. The SDIP presents a phased implementation plan for the improvements based on priorities established during the study and availability of funding. As part of the study, we research sources of potential funding for the projects, including grants, loans, and other funding mechanisms as well as establishment of stormwater utility districts.

Stormwater Permitting

Permitting of stormwater discharges is required for many sources, including large municipal stormwater collection system discharges and most stormwater discharges resulting from industrial activity. During the initial stages of the NPDES stormwater permitting process, many industry groups were allowed to submit group stormwater permit applications under the regulations. We assisted members of the North Carolina, South Carolina, and Georgia Textile Manufacturers Associations with 4 separate stormwater Group Permit Applications which included over 180 facilities throughout the Carolinas, Georgia, Tennessee, Alabama, Virginia, and Delaware. In some states, an individual permit is the only status acceptable for various facilities. We assisted numerous facilities with their individual permit applications as well as compliance with either the group, individual, or general permit. As a part of this permitting strategy, we assist industry in preparing their stormwater permit applications by:

Stormwater Sampling

Since the promulgation of the stormwater regulations, we have helped facilities throughout the Southeast with stormwater sampling and laboratory analysis. Our manual sampling techniques meet EPA requirements and usually are much less costly than automatic samplers. Our environmental engineering staff has produced a stormwater sampling video which provides step-by-step instructions for manual sampling procedures. Site specific stormwater sampling kits are designed for each individual outfall. Given the unpredictable number of false starts associated with rain events, the use of the stormwater sampling video, along with telephone support, allows the individual sites to use on-site staff to sample their own individual outfalls at a tremendous cost savings. However, where cost-effective, we can provide personnel to accomplish required stormwater sampling.

Stormwater Pollution Prevention Plans

We have prepared numerous Stormwater Pollution Prevention Plans (SW3P’s) for industrial and municipal facilities. Preparation of these plans involves:

Often, we become part of the facility’s pollution prevention team. Obviously, a well prepared SW3P can result in a significant reduction in the discharge of pollutants through stormwater discharge points, thereby minimizing potential liability for the facility.

Training

We have assisted numerous groups with Stormwater Compliance. Over 100 industry representatives attended the Georgia Textile Manufacturers Association (GTMA) seminar on stormwater permit compliance in Marietta, GA. The American Textile Manufacturers Institute (ATMI) also sought our assistance to train over 200 of its members on techniques regarding stormwater sampling. Representatives from almost every sector of industry have attended our seminars on preparation of Stormwater Pollution Prevention Plans. We also provide on-site training in proper pollution prevention techniques, sampling and analytical techniques for stormwater, and overall stormwater compliance.

Stormwater Collection and Treatment

We have assisted many municipal and industrial clients with collection and treatment of stormwater. As regulatory limits are placed on stormwater discharges, we continue to be involved with researching current trends as well as new technology for treating stormwater. We were involved in some of the earliest attempts at industrial sites to collect potentially contaminated stormwater runoff, and designed a collection, storage, and treatment system that allowed the facility to collect the first ¼ inch of rainfall, divert it to a storage basin for analysis, and then to transfer it to a treatment system prior to discharge if the analysis indicated treatment was necessary. Subsequently, we have assisted many industries in designing appropriate stormwater management systems.