In 1992, the City of Griffin, GA, made a conscious decision to address the water-quantity issues of flooding and the inadequacy of the worn-out storm drainage system. In 1995, the city created a comprehensive stormwater management program. During the creation of the program, the city discovered that TMDLs were on the horizon in Georgia, as were numerous infrastructure issues. Having to address both water quality and water quantity, Griffin implemented a stormwater utility in 1998, the first in Georgia, to create a dedicated and stable funding method to address these issues. The comprehensive program components include hydrologic and hydraulic modeling, GIS mapping of drainage system’s inventory, watershed assessments of each of its drainage basins, and a detailed road map for operation and maintenance of its program included in the stormwater watershed protection plans, all of which include the use of nonstructural and structural best management practices.In the January/February 2002 issue of Stormwater, I addressed the issue of BMPs and “Do they really work?” and announced that the Federal Highway Administration (FHWA) wanted an answer to that same question. In 1999, FHWA awarded the City of Griffin a TEA-21 grant to find out. TEA-21 supplied $700,000, and the city put up $140,000. While applying for the funding, Griffin was approached by NSF/EPA Environmental Technology Verification (ETV) group to consider making this a collaborative effort, and $150,000 was added to the pot for review, verification, and reporting on the efficiency of pollutant removal of BMP devices on a state highway system. Here is where the challenges began. It took almost two years of working through government processing of papers, meetings, and issues presented to the city, FHWA, vendors, and the ETV. The study’s stated goal was to test the pollutant-removal devices for the claims made by the vendors, with results to be presented in a final report. Practitioners would be able to view the facts and findings and make their own decisions about the products; the study does not focus on which product is the “best.”In the beginning, 11 separation-type device manufacturers were asked to submit for verification; three responded. For stormwater to advance as an engineered science, testing is essential. At the conclusion of the study, we will address in more detail why other manufacturers chose not to participate. Four areas are considered in the TEA-21 research part of the program: (1) review of claims of removal efficiency vs. actual removal, (2) installation and construction costs, (3) maintenance and operation costs, and (4) cost of device. Currently the devices are in the ground, and sampling and monitoring is ongoing. Additionally, the ETV group has selected Griffin for testing of insert devices provided by the two companies that came forward for this testing. In other testing, Griffin is currently in its third year of a Section 319–funded project for the monitoring of a regional detention pond with manmade wetlands installed. Results of these are available on-line at www.griffinstorm.com and are updated annually. Griffin also has an ongoing 319 project to monitor the effects of an existing detention pond retrofitted with BMPs. The results should be completed and available on the Web site in mid-2003. I will publish the results of the findings in Stormwater when the publication cycle allows. Stormwater professionals will have the opportunity to judge for themselves the effectiveness of the BMPs, the associated costs, and the applicability of the devices in their own programs, based on Griffin’s findings.Early observations of separation devices have shown that they can be difficult to work with in treating large surface volumes and–because of space constraints and existing utilities–in municipal retrofit environments. Extensive site review and engineering must take place before selecting installation sites. It has been our experience with vendors that locations must be verified with their representatives. While these types of devices are currently quite pricey for the municipal pocketbook, we can hope that demand and advanced technology can assist in lowering prices. Once testing is completed and hard-core numbers on maintenance and efficiency are collected, we can determine the overall value of installing these devices to the taxpayer or ratepayer.The devices lend themselves nicely to new development and small drainage areas. Parking lots, gas stations, maintenance facilities, and the like are great areas for installation. Pollutant efficiencies are yet to be judged. For the final analysis, the NSF/ETV program will deliver the science on the subject and the TEA-21 program is charged with the practicality and financial return on investment. Data from Griffin’s completed testing will be made available, and you, the stormwater professional, will be able to judge the results and applicability for your own stormwater program. Until then, court is in recess.
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