Draft Source Water Assessment Report
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Draft Source Water Assessment Report Medford Water Commission, Oregon PWS #4100513 June 2005 This Source Water Assessment is still in progress. Medford Water Commission is in the process of finalizing the inventory for its portion of the watershed. Contents Executive Summary Figures Figure 1. Medford Water Commission Drinking Water Protection Area Figure 2. Sensitive Areas within Medford Water Commission’s Drinking Water Protection Area Tables Table 1. Summary of Potential Contaminant Sources by Land Use Table 2. Inventory Results- List of Potential Contaminant Sources Attachments Schematic of Middle and Upper Rogue Sub-Basin Drinking Water Protection Areas and Summary of Source Water Assessment Results for Upstream Intakes Country View Mobile Home Estates Executive Summary The drinking water for Medford Water Commission is supplied by an intake on the Rogue River. This public water system serves approximately 100,000 citizens. The intake is located in the Rogue River Watershed in the Upper Rogue Subbasin of the Rogue River Basin. In addition, MWC uses groundwater springs for drinking water supply. This Source Water Assessment addresses only the surface water component of MWC’s drinking water supply. The groundwater supply is addressed in a separate report. The geographic area providing water to MWC’s intake extends upstream approximately 84 miles in a northeast direction from River Mile (R.M.) 131 and encompasses a total area of 1610 square miles. Included in this area are a number of tributaries to the main stem, including Little Butte Creek, Big Butte Creek, Reese Creek, Long Branch Creek, Trail Creek, Elk Creek, all below Lost Creek Reservoir located on the Rogue River. The following tributaries to the Rogue above the reservoir are South Fork Rogue River, Mill Creek, Union Creek, Abbott Creek, Flat Creek, Bybee Creek, Castle Creek, Foster Creek, Copeland Creek, National Creek, and Muir Creek. The protection area within an 8-hour travel time from the intake extends approximately 8 to 11 miles upstream of the MWC intake. The Rogue River intake is located at an approximate elevation of 1175 feet and the headwaters of the watershed is located at an elevation range of approximately 6000 to 9495 feet, including Crater Lake and Mt. McLoughlin. An inventory of potential contamination sources for the surface water source was performed within MWC’s drinking water protection area. The primary intent of this inventory was to identify and locate significant potential sources of contaminants of concern. The inventory was conducted by reviewing applicable state and federal regulatory databases and land use maps, interviewing persons knowledgeable of the area, and conducting a windshield survey by driving through the drinking water protection area to field locate and verify as many of the potential contaminant source activities as possible. The primary contaminants of concern for surface water intakes are sediments/turbidity, microbiological, chemicals and nutrients. It is important to remember that the sites and areas identified are only potential sources of contamination to the drinking water. Water quality impacts are minimized or not likely to occur when contaminants are used and managed properly and land use activities occur in such a way as to minimize erosion and contaminant releases. The delineated drinking water protection area is primarily dominated by a mix of residential, industrial, commercial, agricultural and forest management land uses. One hundred ninety-nine potential contaminant sources were identified in the watershed. The potential contaminant sources identified in the watershed include the following: Forest Management/ Recreation. Clear cuts. Agricultural Management. Ten areas with grazing animals, one Confined Animal Feeding Operation (CAFO), two irrigation canals, two areas with irrigated crops, one fish hatchery, and areas with non-irrigated crops. Commercial/Industrial. One printing shop, two stormwater detention ponds, three wood treatment operations, seven wood processing operations, two airstrips, five warehouses, two boat repair shops, six furniture/lumber stores, six junk/salvage/scrap yards, nine auto repair shops, seven medical/vet offices, one DEQ Cleanup Program Sites, three metal plating/finishing shops, one railroad maintenance yard, one photo processing plant, four food processing operations, one operation with chemical/petroleum storage, eight gas stations, one random dumpsite, five mine/gravel pits, three stables, one cement/concrete plant, three rock piles, six mini storage facilities, two parking lots, two car washes, and a road maintenance facility. Residential/Municipal. Five fire stations, four areas with high density housing, seven areas with highly maintained lawns, seven parks, one school, two golf courses, one waste transfer station, one landfill, one RV Park, two areas with high density septic systems, and a wastewater treatment plant. Miscellaneous: One railroad, Hwy 62, Hwy 227, Brownsboro-Eagle Point Rd., twenty- five stream crossings, eleven miscellaneous businesses, three upstream dams, one stormwater outfall, four homestead/rural machine shop/area with equipment maintenance, one suspected ECSI site, transmission lines, and a marina. The potential contaminant sources within the drinking water protection area all pose a relatively higher to moderate risk to the drinking water supply with the exception of the medical/vet offices, mini-storage facilities, fire stations, rock piles, non-irrigated crops, ODOT maintenance facility, one of the lumber stores, and four of the miscellaneous businesses, which present a lower risk. Area-wide potential sources such as the residential areas and clearcuts occur throughout the drinking water protection area and are shown on Figure 2 in the location nearest to the intake. The susceptibility analysis combines the results of the locations of the potential contaminant sources with the locations of the sensitive areas. Overlaying the locations of the moderate- to high-risk sources within the sensitive areas provides an indication of the areas that are highly susceptible to contamination. In the MWC watershed, the results of the susceptibility “analysis” include the distribution of 167 identified high- to moderate-risk sources within the areas of highly permeable soils, high erosional soils, high runoff potential soils, and within the 1000’ setback from the streams. The susceptibility analysis provides the community and the public water system with information on where the greatest risk occurs and where to focus resources for protection of this valuable drinking water resource. Figure 1: Medford Water Commission's Drinking Water Protection Area PWS 4100513 Drinking Water Intake - Surface Water Drinking Water Protection Area Note on Base Map: 1:100,000 scale U.S. Geological Survey Digital Raster Graphic (DRGsJ for Medford (1991), and Crater Lake (1989) are displayed. DRGs are scanned images of topographic sneets. Where the DRGs join, seams and/or gaps may be visible. Between DRGs, variations In Information displayed also may be seen. ~ r _,- \ J I ' - ~-" ,. Kllometer1 0 2 3 4 • Mlet Printed Jsnuiny, 2003 Oregon Department of Environmental Quality GIS . Figure 2: Sensitive Areas in Watershed Sensitive Areas within Medford Water Commissi.on's High Soil Erosion Potential (Slope > = 30 Percent and Soil Erodibility Factor > =.25) High Permeability Soils (Alluvial Deposits) Drinking Water Protection Area ;;r,-...,---,,.----c~----;7=:::----.=rr-~~ PWS 4100513 e Drinking Water Intake - Surface Water Drinking Water Protection Area Sources of Information: (Jackson County Area) . High Soil Erodibility: Defined by slopes greater than 30 percent and K factor greater than .25. Soils derived from 1:24,000, USDA, NRCS, SSURGO certified data. Slope is in the SSURGO database Component Table. Slope displayed is a weighted average of the average slope for the map unit. K factor is contained in the SSURGO Layer Table. K factor displayed is a weighted average(of only the surface layer) for the map unit. High Runoff Potential: Hydrologic Group D (very slow infiltration rates) from the SSURGO Component Table. SSURGO data have been certified. (Rogue National Forest) High Soil Erodibility: Defined by high sedimentation yield potential of the dominant soil. High Runoff Potential: Hydrologic Group D in the dominant soil. These data are extracted from the Soil Resource Inventory. (Entire Watershed) High Permeability Soils: Alluvial deposits (Cal) from the U.S. Geological Survey Geologic Map of Oregon GIS layer. Sensitive Area Setbacks Adjacent to Streams and Reservoirs: 1000 foot buffer from the centerline of perennial · streams and the shoreline of any reservoir. Note on Sensitive Areas: In determining the most sensitive areas within this Drinking Water Protection Area, DEO used existing GIS layers and other natural resource agency data sets. Not all areas of the state have been mapped for the natural resource parameters of interest or at the level of detail ideal for this type of analysis. DEQ has sought to obtain the best available information for this composite. ~ Kilometers [iB!] Printed August. 2002 0 10 20 ...,a; Oregon Department of Environmental Quality GIS Composite of Sensitive Areas High Runoff Potential (Hydrologic Group D - slow infiltration rates) ~ ' 0 10 Mile• '.· TABLE 1. SUMMARY OF POTENTIAL CONTAMINANT SOURCES BY LAND USE PWS # 4100513 MEDFORD WATER COMMISSION Relative Total in Potential Contamination Source Notes Risk Level DWPA --~E)~i_d_ential/Municipal