COLUMBIA SLOUGH AREA-WIDE DISCOVERY (CSD) PROJECT Since February 2002, Oregon DEQ’s Northwest Region (NWR) has been working on a project to discover new sites within the Columbia Slough Watershed. The Columbia Slough is a 19 mile- long complex of narrow and shallow channels located on the southern floodplain of the Columbia River between Fairview Lake and the Willamette River in Portland, Oregon. Emphasis on this project has been primarily on two fronts – (a) Discovering new candidate cleanup sites within the Columbia Slough watershed that may have contributed to known sediment and water-quality problems; and (b) Coordinating with the City of Portland’s Bureau of Environmental Services (BES) to perform an intensive discovery effort in a geographic Focus Area within the Columbia Slough. These efforts are briefly described below. Area Wide Discovery This project has focused on the evaluation of numerous information sources, such as online databases, historic files, and existing water quality or sediment data to determine if a region of the Slough, or a specific property, may need to have environmental assessment or cleanup activity. The information sources that were evaluated and applied included the following – DEQ Complaint Database. DEQ Environmental Cleanup Site Information (ECSI) Database. DEQ Facility Profiler database. DEQ Hazardous Waste Handlers Database. DEQ Underground Storage Tank (UST) database. DEQ National Pollutant Discharge Elimination System (NPDES) database. DEQ Stormwater permitting monitoring information. DEQ Underground Injection Control (UIC) database. EPA Toxic Release Inventory (TRI) information. Oregon Water Resources Department (WRD) well logs database. Oregon State Fire Marshall Hazardous Substance Database (Right-To-Know). Polk Directories, City of Portland (historical business and address listing). City of Portland, database of Columbia Slough sediment data. City of Portland, Corporate GIS (CGIS) database (aerials, tax lot, land use). SANBORN maps (historical land use) U. S. Army Corps of Engineers (USACE) aerial photographs files. All of the information sources were compared and screened against each other for selected regions of the Columbia Slough to identify properties that may need further discovery investigation or assessment. Some early success in discovering as-yet unidentified sites came through use of the WRD well logs database. In Oregon, property owners are required to submit a “geotechnical hole” or monitoring well log with WRD whenever one is installed. By calling up known geotechnical holes and monitoring well logs, and then filtering out known ECSI or UST sites, many candidate sites were identified for further research. This aspect of the project is ongoing and will be performed over most of the Slough watershed by the end of March 2003. Through all efforts thus far, NWR has identified nine new sites of COLUMBIA SLOUGH AREA-WIDE DISCOVERY (CSD) PROJECT interest, raised the priority of 5 existing DEQ ECSI sites that were inactive, and of those 5, added 3 to the cleanup program (active or on the waiting list). The nine new sites are: Airgas Norpac American Auto Wrecking Blasen, LLC Central Machine Works Columbia Aluminum & Recycling Continental Brass Fairmount Financial Norstar Business Center UPRR – Kenton Yard. More recently, NWR has been analyzing existing Columbia Slough sediment data to locate areas with the highest contaminant levels. Once NWR has identified specific geographic areas, it will evaluate local businesses for their possible contributions to existing contamination. Geographic Focus Area 1: This aspect of the project was a collaborative effort to combine DEQ’s information sources with the knowledge base of BES. DEQ and BES personnel selected a geographic area in the lower Columbia Slough, between Portland Road and Interstate 5, to gather data and assess candidate sites. This area of the Slough, shown in Figure 1, was chosen based upon a Screening Level Risk Assessment (SLRA) that BES completed in 1995. DEQ applied many of the same information sources and techniques listed above. BES applied its stormwater inspection and historical business record search expertise. The Focus Area was a stretch of the Lower Columbia Slough, from about mile 5.4 to 7.0, that is heavily industrialized: between the south bank of the Slough and N. Columbia Boulevard in North Portland. Historical business records and Sanborn map information has been used to establish commercial and industrial land use back to 1930. BES will soon complete work analyzing how the stormwater conveyance system (both public and private) may tie specific businesses to identified sediment contamination in the Slough. DEQ has primarily used water quality records, well logs, and aerial photography (current and historical) to identify candidate sites. DEQ and BES efforts have thus far achieved the following - (a) two existing DEQ ECSI sites that had been inactive have been assessed as high-priority sites, and are slated to enter DEQ’s Voluntary Cleanup Program; (b) Four previously inactive sites have been selected for additional assessment; and (c) three new sites have been identified. The Focus Area analysis is not complete. The input of the stormwater analysis and an overall evaluation of the collected data have yet to be performed. Additional results are expected. The overall project is expected to be completed in the Spring of 2003. COLUMBIA SLOUGH AREA-WIDE DISCOVERY (CSD) PROJECT Figure 1: Focus Area 1, section of Lower Columbia Slough in north Portland. .