SWV2002GWStudyRpt.pdfINTRODUCTIONPURPOSE AND SCOPE OF THE STUDYThe study area includes the lowlands of the southern portion of the Willamette Valley, extending from Eugene to Albany in Lane, Linn, and Benton Counties (see Figure 2). Areas inside the urban growth boundaries of Eugene, Corvallis, Albany, and LebanSWV2002GWStudyRefs_Glossary.pdfREFERENCESSWV2002GWStudyAttachB.pdfDate Prepared: ____________Field Technician: __________________________Sample collected at: Tap? ______ Well head? ______ Hose bib? ______Field Sampling Parameters:Temperature ______ Conductivity______ D.O. ______ pH ______ Water Level ____SWV2002GWStudyAttachB2.pdfBlankSouthern Willamette Valley 2002 Groundwater Study ABSTRACT During the Spring and Summer of 2002, The Oregon Department of Environmental Quality (DEQ) Groundwater Protection Program studied the current magnitude and extent of non-point source pollution of shallow groundwater in the Southern Willamette Valley. The Southern Willamette Valley is considered by DEQ to be a priority area for groundwater assessment and protection for several reasons, including: the severity and extent of nonpoint source groundwater contamination that has been documented in previous studies; the vulnerability of shallow groundwater to impacts from the overlying land uses; the expectation that the population growth in this area will rapidly expand; and that residents in the unincorporated areas of the Southern Willamette Valley will rely on groundwater as their primary drinking water supply. Water-supply data indicate that more than 80% of the groundwater used in the Willamette Valley is pumped from the shallow sand and gravel aquifer. DEQ previously conducted a nitrate groundwater study of the Southern Willamette Valley in 2000-2001. That study confirmed and supplemented data previously collected by DEQ and other agencies characterizing the nitrate contamination of the in shallow groundwater in the alluvial aquifers. Shallow groundwater, defined as less than 75 feet below ground surface for the purposes of this study, was targeted for sampling as this is the resource most likely affected by anthropogenic activities. The 2002 Southern Willamette Valley study focused on the resampling of wells from the SWV 2000-2001 study with nitrate values greater than 7.0 mg/l. The 2002 study included analyzing well water samples for nitrate, phosphate, iron, manganese, arsenic, lead, bacteria, pesticides, caffeine and other water quality parameters. Nitrate values were fairly consistent with previously reported levels. Fifteen (15) different pesticides were detected in the groundwater of the study area; most were detected at very low concentrations. DEQ will use the results of this and previous evaluations to consider groundwater protection strategies, including the potential designation of Groundwater Management Area(s) or Area(s) of Groundwater Concern in the Valley, consistent with the State Statutes ORS 468B.150-188. If such a declaration is realized, then there will be a need to appoint a Lead Agency to develop a groundwater management plan with input from a Groundwater Management Committee comprised of local stakeholders. The primary goals of such management plans include the development and implementation of best management practices to lessen future groundwater contamination and the determination of appropriate means for current protection of public health and the groundwater resource.I. INTRODUCTION This report describes the work completed by the Department of Environmental Quality (DEQ) Groundwater Protection Program during the Spring and Summer of 2002 to study the current magnitude and extent of non-point groundwater pollution of shallow groundwater in the Southern Willamette Valley. The Southern Willamette Valley is considered by DEQ to be a priority area for groundwater assessment and protection for several reasons: including: the severity and extent of nitrate nonpoint source groundwater contamination documented by previous studies; the vulnerability of shallow groundwater to impacts from the overlying land uses; the expectation that the population growth in is area will continue to rapidly expand, and that residents in the unincorporated areas of this study area will rely on groundwater as their primary drinking water supply. The timing of this study was ideal as planning for future groundwater quality protection strategies resulting from the data allowed for integration and networking with other ongoing high-priority water quality improvement efforts in the Willamette Valley (i.e., Total Maximum Daily Loads [ TMDLs] and the 1010 plans). The location of the Southern Willamette Valley is shown on Figure 1. The goal of DEQ’s Groundwater Program is to ensure that Oregon's groundwater is protected as a resource for all present and future beneficial uses. The protection strategy begins with monitoring and assessment to identify groundwater quality problems. Where nonpoint sources of groundwater contamination are identified, a Lead Agency to develop the Action Plan will be appointed and a groundwater management committees comprised of local stakeholders formed to advise State Agencies developing the groundwater management plan on local elements of the plan. Public education, research and demonstration projects are established to increase public awareness. These plans include development and implementation of best management practices to address groundwater contamination and protection. When groundwater is contaminated from non-point sources at levels that exceed 70% of a Maximum Measurable Level [MML; OAR 340-40-90] for nitrate, or 50% of a MML for other parameters, DEQ is authorized to declare a “Groundwater Management Area.” MMLs are generally equivalent to EPA’s Maximum Contaminant Level (MCL) for public drinking water supply systems. The MML for nitrate is 10 milligrams per liter (mg/L). Once such a declaration is made, responsible agencies and local communities will work together to develop an Action Plan with a focus on the restoration of the groundwater quality. Through the development of an Action Plan, State government can play a key role in helping local governments, residents, and other stakeholders increase their awareness of groundwater quality concerns and mobilize them to take actions leading to groundwater protection and restoration of the water quality of this valuable resource. 2Figure 1 Locale of the