New Search
2 <br /> able to devote the resources necessary to conduct the more comprehensive studies. <br /> • Results can be difficult to interpret. For example, results are most commonly reported in <br /> percent removal rates using a variety of methods for determining the rates for specific <br /> parameters. In addition, as it has been observed that BMPs tend to have more consistent <br /> effluent quality, it is often easier to achieve higher pollutant removal rates with higher <br /> pollutant concentrations. Another example of performance reporting problems is that for <br /> a BMP that includes some infiltration, information regarding the change in pollutant <br /> loads would be just as important as the change in pollutant concentrations. As an <br /> example, if the inflow and outflow concentrations were the same and yet the flow, and <br /> therefore the load, was reduced significantly, looking only at concentrations would be <br /> misleading. As another example, varying design criteria among the same group of BMPs <br /> can make it problematic to fairly compare BMPs even among the same group of BMPs <br /> (e.g., wet ponds). <br /> • Results from BMP studies are highly dependent on many variables that are not always <br /> reported. For example, the results from a swale will be dependent on the watershed size <br /> and imperviousness, slope, vegetation, soil types, rainfall patterns, influent <br /> concentrations, etc. <br /> • Information from non-structural BMPs is often not available for comparison to structural <br /> BMPs. <br /> • Many local BMP studies have been conducted for regulatory documentation purposes and <br /> the data has not yet been evaluated or used to support management decisions related to <br /> BMP implementation. A lot of potentially good information, that represents a significant <br /> investment, has not yet been put to use. <br /> Purpose <br /> The purpose for this Request for Proposals (RFP) is to solicit proposals for a project whose <br /> ultimate product will establish a common basis for assessing and documenting BMP <br /> effectiveness for use by Oregon MS4 NPDES permittees in fulfilling the evaluation and reporting <br /> requirements of the new and renewed NPDES Phase I stormwater permits, especially in relation <br /> to the 303(d) and TMDL water quality parameters. In addition to providing support for NPDES <br /> Phase I reporting requirements, the product of this project will also provide support for NPDES <br /> Phase II stormwater management planning efforts and assessment of BMP effectiveness <br /> necessary to comply with stormwater groundwater injection wells under the Oregon <br /> Underground Injection Control (LTIC) regulations. The guidance tool will identify the best <br /> available information that can be used to efficiently allocate resources in the selection and <br /> implementation of BMPs. The guidance tool will also be used to support future BMP monitoring <br /> and reporting efforts. Significant gaps in existing information about BMP effectiveness will be <br /> identified so that jurisdictions will be able to assess and modify their stormwater program <br /> monitoring to address informational needs while making the best use of the significant <br /> investment that has already been made to date on BMP evaluations. <br /> <br /> PAGE 2 REQUEST FOR PROPOSALS - - Stormwater BMP Effectiveness Review <br /> <br /> February, 2003 <br /> <br />