Availability of Open-File Report 93-39, "Procedures for Adjusting Regional Regression Models of Urban-Runoff Quality Using Local Data," In Reply Refer To: June 14, 1993 Mail Stop 415 OFFICE OF SURFACE WATER TECHNICAL MEMORANDUM NO. 93.18 SUBJECT: Availability of Open-File Report 93-39, "Procedures for Adjusting Regional Regression Models of Urban-Runoff Quality Using Local Data," by Anne B. Hoos and Joy K. Sisolak The purpose of this memorandum is to announce the availability of Open-File Report 93-39 and to make a limited distribution. Because of plans to publish it as a Water-Supply Paper, only a limited number of the report were printed. Hence, only one copy each is being sent to regional, district, and major subdistrict offices. This copy should be brought to the attention of project leaders working in the field of urban stormwater quality. Additional copies are available from the Tennessee District by contacting the principal author, Anne B. Hoos, or the District Chief by EDOC or by calling (615) 736-5424. The report, funded by the Office of Surface Water, discusses methods for using local data to adjust regional regression models for predicting stormwater quality at unmonitored sites. The regional regression models are those published in Water-Supply Paper 2363, "Techniques for Estimation of Storm-Runoff Loads, Volumes, and Selected Constituent Concentrations in Urban Watersheds in the United States," by N. E. Driver and G. D. Tasker. The methods for adjusting the models were tested using data from Denver, Colorado; Bellevue, Washington; and Knoxville, Tennessee. Use of these methods permits more statistically accurate prediction of water-quality parameters than would be possible with either the regional regression models or a limited local data set, used separately. Software to implement these methods is available from the principal author. A number of Water Resources Division offices have cooperative programs with local governments to evaluate stormwater quality as part of the Environmental Protection Agency's NPDES (National Pollution Discharge Elimination System). The methods from Open- File Report 93-39 will be useful in these programs and may be useful in similar studies, such as the Army Stormwater Runoff Program. Charles W. Boning, Chief Office of Surface Water Attachment DISTRIBUTION: A, B, FO, PO (w/o attachment) FO (1 copy only of attachment)