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Source Water Assessment Report -CITY OF SANDY ELECTRONIC DOCUMENT ARCHIViNG FOLDER STRUCTURE. ----- (department) . ~ DOCUMENT NAME~Ct_~ ,., DATE RANGE: 2006-2010 --_____ 2000-2005 ---_____ 1995-2000 -__.k_ 1990-1995 -____ 1985-1990 ' 1980'1985 ~ . -___._ 1975-1980 --____ 1970-1975 _._____'Before 1975 RETENTION: ._____ None ___.____ '1 year _______ 2 years -; ___.___ 5 years _____ 10 years ___.__ 20 years ---~ Permanent DISPOSITION OF DOCUMENT AFTER SCANNING: ~ Return to Department' .______ Recycle ' \\Server0 l\dataWorms All DepartmentsLttrchive Storage Box Index and Plan Box [ndex\Rlac. tron.i,~ SOURCE WATER ASSESSMENT REPORT Summary of Analysis City of Sandy Sandy, Oregon Clackamas County PWS #4100789 February 2005 Prepared By Oregon Department of Human Services Health Services Drinking Water Program And Oregon Department of Environmental Quality Water Quality Division Drinking Water Protection )~'DHs Available in Alternate Formats by contac~i_ng the DHS DWP at (541)_~26-2587 Department of Human Services Drinking Water Program Springfield Field Office 444 A Street Springfield, Oregon 97477 Dennis Nelson (for questions concerning this report) donelson~oregonvos, net (541) 726-2587 ext 21 Fax (541) 726-2596 Main Office 800 NE Oregon Street, Room 611 P.O. Box 14450 Portland, Oregon 97293 (503) 731-4317 Fax: (503) 731-4077 Pendleton Field Office 700 SE Emigrant Pendleton, OR 97801 (541) 276-8006 (541) 276-4778 Website: http://www.dhg.state'°r'us/Publichealthldwplindex'cfm Department of Environmental Quality - Headquarters Water. Quality Division Drinking Water Program 811 SW 6~ Avenue Portland, Oregon 97204 ' Julie Harvey (for assistance in developing a drinking water protection plan)' . l~ARVEY.J~l~et~deq.state.or.~ (503) 229~5664 . Fax (503) 229-6.124 Website: ~._S_t_ate.or.us/wq/dwp/dwphome.htm Oregon Association of Water Utilities 12312 Silverton Rd. NE Silverton, Oregon 97381 Mike Hayes (for assistance in developing a drinking water protection plan) (503) 873-8353 Fax (503) 873-8538 Website: www.orednet.org/--oawu Oregon Home*A*Syst Education Program OSU Extension/Bioresource Engineering Oregon State University Corvallis, Oregon 97331-3906 Gail Glick Andrews (for outreach information concerning private wells/septic systems) (541) 737-6294 Website: h__t__tp3~I/wellwater.orst.edu Department of Environmental Quality Western Region Eugene Office 1102 Lincoln Street, Suite 210 Eugene, OR 97401. (541) 686-7838 FAX (541) 686-7551 TTY (541 ) 687-5603 February 9, 2005 Mike Walker City of Sandy 39250 Pioneer Blvd. Sandy, OR 97055 Dear Mr. Walker: The'respective Drinking Water-related Programs of the Department of Human Services (DHS) and the Department of Environmental Quality (DEQ) are pleased to transmit the accompanying Source Water Assessment Report for the City of Sandy's groundwater derived Public Water Supply to you as the system's representative. The document provides the system with a. map of the Drinking Water Protection Area for the water system's spring, an inventory of potential contaminant sources, a susceptibility analysis for the water system's drinking water supply and a discussion of the potential use(s) of the report. As mandated by the 1996 Amendments to the Safe Drinking Water Act, the report provides the water system with the data necessary to develop a site-specific plan for protecting the system's future drinking water resources if they choose. It is also hoped that the report will provide sufficient information about groundwater in the region so that the water system and County are able to make land use decisions in a manner consistent with protecting the resource. With respect to land use decisions, it is important to understand that the boundaries of the drinking water protection area shown on the accompanying maps represent our best professional judgment based on the information available to us at the time. Although we are confident that the area delineated in fact represents the bulk of the capture zone for the system's spring, it should be understood that, given the uncertainties in the data used to determine the area, it is possible that some groundwater may enter the capture zone from outside the illustrated boundaries. DEQ-DCI regon Theodore R. Kulongoski, Governor February 3, 2005 To: City of Sandy Department of Human Services Health ServiCes Drinking Water Program 444 A Street Springfield, OR 97477 (541) 726-2587 Ext. FAX (541) 726-2596 TTY-Non Voice (503) 731-4031 From: Amy Parmenter DEQ Drinking Water Protection Program Subject: Reporting Completed Source Water Assessment in your CCR As you are aware, the Safe Drinking Water Act requires that all community water systems distribute a consumer confidence report to their customers by July 1 st of each year. Questions regarding the specific requirements surrounding the CCR can be addressed to Tom Mitchell at 503-731-4010. The purpose of this letter is to offer you language for your CCR as related to the Source Water Assessment program. As part of the Source Water Assessment program, you haVe received a completed Source Water Assessment Re_port for your drinking water source. The EPA has indicated that if the Source Water Assessment has been completed for a water system, the CCR must notify consumers of the availability of the rePort and the means to obtain it. In addition, a brief summary of the Source Water Assessment results should be included in the CCR using language provided by the Drinking Water Program or written by the water system operator. Therefore, I have suggested some language below for inclusion in your future reports. It is also my understanding that you are required to supply the name of the aquifer from which you are deriving your water which I've also included below. If you have any questions, please feel free to contact me at 541-686-7838 ext. 278. Suggested Statement for Consumer Confidence Report The 1996 Amendments to the Safe Drinking Water Act require that all states conduct Source Water Assessments for public water systems within their "Assisting People to Become Independent, Healthy and Safe" An Equal Opportunity Employer IF YOU WOULD LIKE THIS IN ALTERNATE FORMAT, PLEASE CALL DENNIS NELSON AT (541) 726-2587 EXT. 21 boundaries. The assessments consist of (1) identification of the Drinking Water Protection Area, i,e., the area at the surface that is directly above that part of the aquifer that supplies groundwater to our well(s), (2) identification of potential sources of pollution within the Drinking Water Protection Area, and (3) determining the susceptibility or relative risk to the well water from those sources. The purpose of the assessment is to provide water systems With the information they need to develop a strategy to protect their drinking water resource if they choose. The respective Drinking Water programs of the Departments of Human Services and Environmental Quality have completed the assessment for our system. A copy of the report is on file at the Water system's office. Regarding the Source Water Assessment Report The City of Sandy water system draws water from a shallow, unconfined, layered volcanic aquifer in the Boring 'Lava. Assessment results indicate that the water system would be highly sensitive to a contamination event inside the identified Drinking Water Protection Area. The presence of a couple moderate- and' low-risk potential contaminant sources within the protection area was confirmed through a potential contaminant source inventory. Under a "worst case" scenario, where it is assumed that nothing is being done to protect groundwater quality at the identified potential contaminant sources, the assessment results indicate that the water system would be highly susceptible to the identified moderate-risk potential contaminant source. In addition, the assessment results indicate that, at this time, the water system is considered susceptible to viral contamination. SOURCE WATER ASSESSMENT REPORT Summary of Analysis City of Sandy Sandy, Oregon Clackamas County PWS #4! 00789 February 2005 Prepared By Oregon Department of Human Services Health Services Drinking Water Program And Oregon Department of Environmental Quality Water Quality Division Drinking Water Protection )~DHs · On,giro cfi Human State of Oregon Environmental Quarry Available in Alternate Formats by contacting the DHS DWP at (541) 726-258'/ TABLE OF CONTENTS 1. INTRODUCTION .................................... ~®~e~e®~e~®~®®~~®~®~®~e®~ee*~e~®®®~®®ee®~® 1 2. WATER SYSTEM BACKGROUND .............. eeooooooeoeeeeeeeeeeoeeooee·eeeeeeeeeeeeeoeeoeooeoeeee· eeeee®®eoeeoeeoe 2 2.1 LOCATION OF THE DRINKING WATER SOURCE(S) .................................................................. 2 2.2 SOURCE CONSTRucTioN ................... 2 2.3 NATURE AND CHARACTERISTICS OF THE AQUIFER ................................................................ 3 3. DELINEATION RESULTS ............................... . eeeeeee~eeeeeeee eeeeeeeeeeeeoe~ee®eeeeeeeeeeeeeeeee~leeeeeele·eeeeee~ 4 4. SENSITIVITY ANALYSIS RESULTS ................... 5. POTENTIAL CONTAMINANT SOURCE INVENTORY ................................................. 8 5.1 WITHIN SPRING RECHARGE AREA 6. SUSCEPTIBILITY OF THE DRINKING WATER SOURCE .......................................... 9 6. l AQUIFER SUSCEPTIBILITY TO POTENTIAL CONTAM[NANT SOURCES INSIDE THE DRINKING WATER PROTECTION AREA ...................... 6.2 WATER SYSTEM .................................................................................... 9 SUSCEPTIBILITY TO VIRAL CONTAMINANT SOURCES WITHIN THE SHORT- TERM (ZONE 1) GROUNDWATER SUPPLY AREA ......................................................................... ] ] 7. CONCLUSIONS ................... ~'eeee°e'e'e °~'eeee eee,,,*,,ooeoo o o o ~ ooo co ,,eo °e°°®e°oo®ooooooooeoeoeo,ooeeeeeeeeeeeeeo®eooeoeeeeeeeeoeeeee 12 8. RECOMMENDED USE OF THE SOURCE WATER ASSESSMENT REPORT ......... 13 APPENDIX MATERIALS ............. ~e~e~e~®~®~®~~e®~ee~®~e®®~®~e®~e~®~®~®~ 16 City of Sandy Source Water Assessment Report Summary of Analysis 1. Introduction The Source Water Assessment Program, mandated by the 1996 Amendments to the Safe Drinking Water Act, requires 'that states provide the information needed by public water systems to develop drinking water protection plans if they choose. That information includes the identification of the area most critical to maintaining safe drinking water, i.e'., the Drinking Water Protection Area, an inventory of potential sources of contamination within the Drinking Water Protection Area, and an assessment of the relative threat that these potential sources pose to the water system. The intent of this report is to present our conclusions regarding the source water assessment analysis for your water system. It is our hope that this information will be used as a basis for reducing the risk of contamination to your water source through the development of a voluntary Drinking Water Protection Plan (DWPP). Should you decided to proceed with the development of a DWPP, this document can serve as the foundation for the plan. If, however, a more in depth analysis of the local hydrogeology, water system susceptibility, and/or the water system specific assumptions is needed to help promote the development of a DWPP, a more comprehensive' assessment analysis can be made available to you by contacting either the DHS Project Manager or the DHS Drinking Water Program Groundwater Coordinator. The methodology that the Source Water Assessment results are based on is included in the attached appendix materials under the heading, "Source Water Assessment Methodology". This includes a discussion of the source water assessment project; groundwater basics; and the processes involved with conducting the delineation, sensitivity analysis,' potential contaminant source inventory, and overall water system susceptibility. Therefore, it is our intention that the assessment results, identified in this portion of the report, be used in conjunction with the methodology and rational presented in the appendix materials. For instance, if questions arise regarding our conclusions with respect to a specific element of the assessment (i.e. type of delineation used, aquifer sensitivity, springbox construction sensitivity, etc...), the methodology that lead to our conclusions can be reviewed in the appendix materials for further clarification. We believe public awareness is a powerful tool for protecting drinking water and that the information provided in this report will help you increase local awareness regarding land use activities and local drinking water quality. We have also included a "Groundwater Fact Sheet" and a list of Oregon specific drinking water protection information and resources titled "Drinking Water Protection in Oregon" in the appendix materials. 2. Water System Background The City of Sandy is located in Clackamas County and.serves approximately 6,250 people through 2,000 connections. Drinking water is supplied by one surface water source (Alder Creek) and one groundwater source (Brownell Springs). According to DHS 'Drinking Water Program records, both the creek and spring serve as permanent water sources. This report will address only the groundwater source; the surface water source is addressed in a separate report. 2.1 Location of the Drinking Water Source(s) We have located your drinking water source(s) using a Trimble GeoExplorer I1 Global Positioning System (GPS) unit. The data has been differentially corrected to remove some of the common positioning errors. The location of the source(s)~ with the corresponding Drinking Water Protection Area, has been placed in a Geographic Information System (GIS) layer and projected onto a USGS 7.5 minute topographic map that is included within this report. In order to be consistent with the topographic map, the projection uses the NAD1927 datum. The latitude and longitude values given on the map and below, however, reflect a projection in the more commonly used WGS1984 datum. Data collection specifics include: · 150 individual measurements, · linked to a minimum of four satellites, · a PDOP of less than 6 (pertains to precision of measurement), and · a signal to noise ratio of greater than 5. The raw data was subjected to differential correction using the PATHFINDER software. The location data for your drinking water source(s) using the WGS84 datum is as follows: Source Springs - Source Latitude 45° 21' 34.6" N ________~gitude 122° 9' 14.0" W 2.2 Source Construction The exact age of the springbox is unknown; however, according to the water system, it is likely approximately 50 to 80 years old. In a sanitary survey conducted on 3/31/99, DHS Drinking Water Program staff determined that there are no spring deficiencies pertaining to 'drinking water protection. The spring construction consists of fencing, a springbox, a watertight hatch with a screw-on lid. a diversion ditch, and a screened overflow. A bottom drain, collection piping, and an impervious barrier were not observed. 2.3 Nature and Characteristics of the Aquifer Based on the well report for a proximal well and Leonard and Collins' 1983 hydrogeologic investigation of the area, the aquifer supplying the spring is composed of layered volcanics of the Boring Lava. The well report for what appears to be the closest well to the spring within the DWPA, CLAC 57844 (see Appendices), shows the first water-bearing zone from 60 to 90 feet with a static water level of 40 feet. Leonard and Collins (1983) report that approximately half the wells in the area tap shallow aquifers (less than 100 feet) in the Boring Lava. Based on information available in the report for the proximal well and the hydrogeologic investigation, the aquifer supplying the spring is considered to be a shallow, unconfined, layered volcanic aquifer with a depth of less than 100 feet near the spring. According to Leonard and Collins (1983), Brownell Spring has a discharge rate of approximately 400 gpm from the Boring Lava. The 1999 Sanitary Survey reports the discharge rate' as up to 530 gpm with a small seasonal variation and the water temperature as 8.8° C, which "varies little". The specific conductance was not reported. 3. Delineation Results The purpose of the Drinking Water Protection Area (DWPA) delineation is to identify the area at the surface which overlies the critical portion of the aquifer that's supplying groundwater to the water system's well(s) and/or spring(s). Therefore, DHS Drinking Water Program staff have collected and reviewed data for the purpose of delineating the DWPA for your water system. The area included in the DWPA is designed to approximate the long-term groundwater supply for the water system, and is shown in Figure I (see appendix materials). The scope of work for this portion of the assessment included interviewing the water system operator, researching written reports, reviewing local well logs to help interpret geology, and establishing a base map of the delineated area. Based on geologic characteristics, topographic mapping was used to delineate the DWPA for the spring(s). The resulting DWPA is shown in Figure 1 (see appendix materials). Specific information regarding the parameters used in the delineation process including; the delineation method, estimated flow rate, and aquifer characteristics can also be found in the appendix materials. In most cases, three specific "Zones" have been identified for the spring(s) on the DWPA map presented in Figure 1, (see appendix materials). The Zone 1 areas are the closest to the spring(s) and include the surface water drainage immediately upslope from the spring(s). This area represents the short-term water supply to the spring(s) where there is a high probability that rainfall infiltrating into the ground within this area discharges at the spring(s) in a relatively short time period. Therefore, it is reasonable to assume that accidents and/or high-risk land use practices which occur within Zone 1 areas could have a negative impact on drinking water quality. The area(s) identified as Zone 2 represent the intermediate groundwater flow regime for the ' spring(s). These areas are surface water drainages directly adjacent to the Zone 1 areas which drain surface water toward the same general location as the surface water captured in the Zone 1 area(s). In an unconfined aquifer, groundwater will move in the same general direction as the slope of the land. Therefore, it is assumed that there is a potential for groundwater to move laterally from the Zone 2 area(s) into the adjacent Zone 1 area(s) and provide a significant amount of discharge to the spring(s). The Zone 3 area(s) represents the origin Of the long-term groundwater flow regime or regional recharge area for the spring(s) and thus, the long-term water supply. The Zone 3 boundaries were identified by mapping portions of the surface water drainages that are at a higher elevation than the spring(s) and were also in contact with Zone I and/or Zone 2. Surface water within the Zone 3 area is typically carried away from the spring(s), however the-potential exists for the underlying geologic structure of the area to dip (slope) back toward the spring(s) in the subsurface thus forcing groundwater to move in a different direction than surface water. Any groundwater moving from these areas toward the spring(s) is believed to take a longer period of time to reach the spring(s), therefore the occurrence of a contamination event in this area is not likely to have an immediate impact on water quality at the spring(s). 4. Sensitivity Analysis Results After the Drinking Water Protection Area (DWPA) has been identified, aquifer susceptibility to potential contaminant sources inside the DWPA can be evaluated. Aquifer susceptibility is dependent on two factors, the natural environment's characteristics that permit migration of a contaminant into the aquifer (i.e., aquifer sensitivity) and the presence, distribution, and nature of the potential contaminant sources within the DWPA. It should be understood that the public water system's drinking water source cannot be susceptible to contamination, even if potential contaminant sources are present, unless the aquifer or the constructed source water intake are sensitive to contamination. Therefore, the intent of the sensitivity analysis is to identify those areas within the DWPA where the aquifer is most sensitive to contamination. The analysis is based on data collected or generated during the DWPA delineation process and is designed to meet the needs of other existing or developing programs such as Monitoring Waivers and the Groundwater Rule. The results of the sensitivity analysis are provided in the tables that follow. Information and sensitivity ratings regarding the aquifer and water quality are provided in Table 4.1 while information and sensitivity ratings regarding the springbox and its construction is provided in Table 4.2. Clarification of the ratings are provided as comments where appropriate. Based on this analysis; the construction of the springbox is not considered highly sensitive to contamination; however, the natural condition of the aquifer is considered highly sensitive because of its shallow, unconfined nature and high Infiltration Potential Score. The age of the springbox and the presence of highly permeable soils within the DWPA contribute to a moderate overall water system sensitivity. Sensitivity Analysis Tables follow, beginning on the next page. Table 4,1 A uifer Sensitivi Anal sis · Sensitivity Parameter H~~ Comments Estimated flow rate. Up to 530 gpm With a small seasonal variation per 1999 Sanitary Survey. Aquifer characteristics and geologic v/ Shallow, unconfined' interflow factors controlling spring, zones of the Boring' Lava. Overburden thickness and characteristics Unknown. at spring outflow. · Fractured bedrock exposed at outflow. Unknown. Traverse potential score, v/ Score = 3 Infiltration potential score. ~/ Score = 8 Organic chemical detections. '/ None detected. 'Inorganic chemical detections. ~/ Barium and chromium <50% MCL. See paragraph following Table 4.1. Source related coliform detections, v/ None detected. Nitrate concentrations (Drinking Water ~ 0.04 mg/L in 2002. Considered Standard = 10 mg/L. to come from natural sources. Number of wells within 500 ft'of spring ~ None observed. inside DWPA. Number of wells within 200 ft of spring v/ None observed. inside DWPA. Specific conductance in laS/cm. Unknown Seasonal variations in flow, temperature, Flow: small variation. or specific conductivity, v/ Temperature: constant. Spec. Conduct: unknown. Highest soil sensitivity in Protection Area. v/ Contributes to moderate aquifer sensitivity. Surface water within 500 ft of spring inside / None present. DWPA. Other: Sodium detection >20 mg/L. / No The presence of barium and chromium (see "Inorganic Chemical Detections" in Table 4.1) at concentrations less than 50% of the MCLs is likely due to natural sources; however, be aware that the possibility of unnatural contributions exists. Table 4.2 Springbox Construction Sensitivity Analysis Sensitivity Parameter H M L Comments Spring construction and/or setback ~ 'None observed. deficiencies from site visit. ~ No Commingling of aquifers suspected. ~ Estimated-50-80 years old, per Age of springbox, water system. 5. Potential Contaminant Source Inventory An inventory of potential contamination sources was performed within the Drinking Water Protection Area and the results are shown in Figure 2, (see appendix materials). The primary intent of the inventory was to identify and locate significant potential contaminant sources of concern. This 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. It is important to remember the sites and areas identified are only potential soUrces of contamination to the drinking water. Environmental contamination is not likely to occur when contaminants are used and manag_e__d_d 5.1 Within Spring Recharge Area The delineated spring recharge area is primarily dominated by a mix of forestry and residential land use. Two potential contaminant soUrce locations (Reference Numbers five and six on Figure 2 and Table 2 in the appendix) were identified in the spring recharge area and include clearcuts and rural homes. The potential contaminant sources within the spring recharge area all pose a relatively higher to moderate risk to the drinking water supply with the exception of the rural homes, which present a lower risk. Area-wide potential sources such as the residential areas and forestry areas occur throughout the drinking water protection area and are shown on Figure 2 in the location nearest to the spring. In addition, an auto wrecker was identified located just outside of the drinking water protection area. This potential source is included in .this inventory because it poses a high degree of potential contamination risk. 6. Susceptibility of the Drinking Water Source In general, Potential Contaminant Sources (PCSs) within the short-term groundwater supply area pose a greater risk than those in the intermediate- and long-term supply areas. Also of concern is the location and distribution of these sources with respect to high and moderately sensitive areas. Overlaying the PCS location map (Figure 2, appendix materials) on top of the sensitivity map for the water system provides a tool that helps determine the susceptibility of the community's drinking water supply to contamination from each PCS (see Figure 3, appendix materials). 6.1 Aquifer Susceptibility to Potential Contaminant Sources Inside the Drinking Water Protection Area Table 6.1, indicates the relationship between potential contaminant source risk, aquifer sensitivity, and estimated contaminant arrival time at the well, wellfield, and/or spring. The community can use the PCS location numbers on the inventory map in conjunction with the displayed aquifer sensitivity and relative risk rankings for each PCS from Table 2 (see appendix materials) to identify the susceptibility of the drinking water source to contamination from each PCS and take steps to reduce the risk accordingly. We have attempted to quantify the relative susceptibility of the water system with regard to the PCSs present in the Drinking Water Protection Area (DWPA) using Table 6.1. Across the top of the table, each critical groundwater supply area within the DWPA (short-, intermediate-, and long-term) is subdivided to account for areas of high, moderate, and low sensitivity that may exist within the area. Potential contaminant source risk categories (high, moderate, and low) are listed down the left hand side of the table. The relative aquifer susceptibility to each PCS is demonstrated by the shading of each cell in the table. Cells that are shaded dark gray indicate a highly-susceptible condition, light gray shaded cells indicate a moderately-susceptible condition, and white cells indicate conditions of low susceptibility. The number in each cell indiCates the number of potential contaminant sources that meet the conditions for that cell. Cells that do not contain a number indicate that there are no known potential contaminant sources that meet the conditions for the cell. Potential contaminant sources that meet the specific criteria for a cell in Table 6.1 can be identified by reviewing Table 2 in the appendix materials. The number of potential contaminant sources is totaled across the bottom of the table. Table 6.1. City of Sandy Spring Susceptibility as a Function of PCS Risk and Aquifer Sensitivity. High Risk PCSs Moderate Risk PCSs Low Risk PCSs Total PCSs Drinking Water Protection Area High Mod Low ! 1 2 The distribution of high, moderate, and low sensitivity areas inside the Drinking Water Protection Area can be determined using either soil sensitivity or the mapped distribution of Traverse Potential (TP) or Infiltration Potential (IP). In the case of the City of Sandy water system, we have decided to rely upon the distribution of soil sensitivity since there are not enough wells within the DWPA to make an accurate determination of the nature of the subsurface. Therefore, the soils overlying the aquifer represent the first line of natural protection for the aquifer. During the potential contaminant source inventory, a total of two potential contaminant source locations and two potential contaminant sources were identified inside the DWPA. As indicated in the above table, both potential contaminant sources occur inside Zone 1. Of the potential contaminant sources identified inside Zone 1, one is of moderate-risk and one is of low-risk. Based on the analysis results shown in the relative susceptibility table, we consider the City of Sandy to be highly susceptible to the moderate-risk potential contaminant source identified inside Zone I (Potential contaminant Source Reference No. 5 on Figure 3, appendix materials). Therefore we recommend that this potential contaminant source not only be addressed in any Drinking Water Protection Plan but also in any Water System Emergency Response Plan. As a result of this analysis, we recommend that the water system develop a Drinking Water Protection Plan that addresses all high- and moderate-risk potential contaminant sources within the DWPA, beginning with. those sources which represent the greatest susceptibility risk. At a minimum, the water system should work with representatives from those PCSs posing a moderate- to high-susceptibility risk within the DWPA to (1) determine the level of environmental protectiOn employed in the day-to-day operations of the facility and (2) identify any reasonable Best Management Practices that will lead to an overall reduction of contamination risk. l0 6.2 Water System Susceptibility to Viral Contaminant Sources within the Short-Term (Zone 1) Groundwater Supply Area The DWPA identifies the short-term groundwater supply for the City of Sandy Spring, which we consider roughly equivalent to a two-year water supply. The two-year time frame is used as a conservative estimate of the survival time for some viruses. Based on the assessment results, the construction of the springbox is not considered sensitive to microbial contamination; however, the aquifer is considered sensitive to microbial contamination within the DWPA due to the shallow, unconfined nature of the aquifer and the high Infiltration Potential Score. The overburden thickness, the presence of fractured bedrock at the outflow, and the Specific Conductance is unknown. Since viral contaminant sources (septic systems) have been identified within the DWPA~ we consider the natural condition of the aquifer to be susceptible to viral contamination. Therefore, it is in the water system's best interest to reduce the potential for future viral contamination by complying with all Oregon Department of Human Services setback standards related to public drinking water supply sources. 7. Conclusions The City of Sandy water system draws water from a shallow, unconfined, layered volcanic aquifer in the Boring Lava. Assessment results indicate that the water system would be 'highly sensitive to a contamination event inside the identified Drinking Water Protection Area. The presence of a couple moderate- and low-risk potential contaminant sources within the protection area was confirmed through a potential contaminant source inventory. Under a "worst case" scenario, where it is assumed that nothing is being done to protect groundwater quality at the identified potential contaminant sources, the assessment results indicate that the water system would be highly susceptible to the identified moderate-risk potential contaminant source. In addition, the assessment results indicate that, at this time, the water system is considered susceptible to viral contamination. 12 8. Recommended Use of the Source Water Assessment Report The costs associated with contaminated drinking water are high. Developing an approach to protect that resource, such as a Drinking Water Protection Plan, can reduce the potential for contamination of the local drinking water supply. This report contains a summary of the local geology and springbox construction issues as they pertain to the quality of your drinking water source. We have identified the area we believe to be most critical to preserving your water quality (the Drinking Water Protection Area) and have identified potential sources of contamination within that area. In addition, we provide you with recommendations, i.e., Best Mana e~nt Practices re_ ard'm-' the _.ro .:er use and r~ces associated with some common potential contamination sources (see appendix materials). We believe public awareness is a powerful tool for protecting drinking water and that the information provided in this report will help you increase local awareness regarding the relationship between land use activities and drinking water quality. To that end, the process for developing a Drinking Water Protection Plan can be summarized as follows: Assessment Phase (Source Water Assessment Provided by DHS and DEQ) · Delineate the area that serves as the source of the public water supply (Drinking Water Protection Area (DWPA)) · Inventory the potential risks or sources of contamination within the DWPA · Determine the areas most susceptible to contamination Protection Phase (performed by the water system or community) · Assemble a local Drinking Water Protection Team · Enhance the Source Water Assessment if necessary · Develop a plan to reduce the risk of contamination (protect the resource) · Develop a contingency plan to address the potential loss of the drinking water supply · Certify (optional) and implement the Drinking Water Protection Plan The assessment phase was funded by the federal Safe Drinking Water Act. Its purpose is to supply the water system with the information necessary to develop a Drinking Water Protection Plan. In Oregon, development of a protection plan is voluntary. Prior to moving into the protection phase, DEQ recommends the inventory presented in this document be reviewed in detail to clarify the presence, location, operational practices, actual risks, etc., of the identified facilities and land use activities. The Source Water Assessment ~WA) inventory should be regarded as a preliminary review of potential sources of contamination within the drinking water protection area. Resources within the cormnunity should be used to do an "enhanced inventorv" to refine this preliminary list of potential contaminant sources. ~ It is also important to remember that not all of the inventoried activities will need to be addressed if you choose to develop a Drinking Water Protection Plan. When developing a protection plan, potential contaminant sources which pose little or no threat to your drinking water supply can be screened out. For example, if any of the land use activities are conducted in a manner that already significantly reduces the risk of a contamination release, the facility would not need 'to re-evaluate their practices based on drinking water protection" ,, management . One of the goals for developing a plan based on the inventory results is to address those land use activities that do pose high or moderate risks to your public water supply. The system should target these facilities with greater levels of education and techniCal assistance to minimize the risk of contamination. Limited technical assistance is available through the DEQ and Drinking Water Program at DHS for water systems that choose to move beyond the assessments and voluntarily develop a Drinking Water Protection Plan. By using the results of the assessment, the water system/community can form a Drinking Water Protection Team comprised of individuals that have a stake in the plan's implementation. Forming a local team to help with the development of a protection plan is very important. Oregon's drinking water protection approach relies upon the concept of "community based protection", as are many other water quality programs. This simply refers to the concept of allowing local control ~d decision-making to implement the water quality protection effort. Community-based protection is successful only with significant local citizen stakeholder involvement. Community-based protection can draw on the knowledge and successful adaptive practices within the area. Landowners generally know best how to achieve water resource restoration and protection as long as a thorough explanation of the problem is provided, the objectives to solve the problem are clearly defined, and technical assistance is available. In community-based protection, citizens have more control and are therefore more likely to participate in the program and be more willing to assist with the educational and outreach effort which will make the plan successful. We recommend that the protection plan be developed so as to minimize any burdens on individual property owners, but maximize the equity in responsibility for reducing the risks of future contamination. Protecting the drinking water supply in a community can also be a very effective way to encourage all citizens to participate in issues which directly affect everyone in that community. This often leads to more public involvement in other significant local decisions concerning future livability issues, e.g., land use planning. In communities already developing and · implementing Drinking Water Protection Plans, the process has served to bring many diverse Interests together on a common goal and strengthen the local rural and urban relationships through communication and increased understanding. The risks and sources of water quality problems_ are not only from industries, farmers, and managed forest, but every individual living, commuting, and working in that area. 14 Communities/water systems interested in developing Drinking Water Protection Plans may contact the Department of Environmental Quality (503-229-5413) or the DHS Drinking Water Program (541-726-2587) for further,information. Appendix Materials References Figures Inventory of Potential Contaminant Sources Well Reports and/or Source Construction Information Used 'to Determine Local Geology Parameters Used in Delineation Model Groundwater Fact Sheet BMPs for Activities Commonly found in Drinking Water Protection Areas Drinking Water Protection in Oregon Source Water Assessment Methodology Additional copies of the appendix materials are available upon written request to the following address: Groundwater Coordinator Drinking Water Program Department of Human Services 444 A Street Springfield, OR 97477 References Gerig, Allen J., 1985. Soil Survey of Clackamas County Area, Oregon. U.S. Department of Agriculture and Soil Conservation Service. Leonard, A. R. and Collins, C. A., 1983. Ground Water in the Northern Part of Clackamas County, Oregon. Oregon Water Resources Department, Ground Water Report No. 29. National Oceanic and Atmospheric Administration (NOAA), 1982. Monthly Normals of Temperature, Precipitation, and Heating and Cooling Degree Days 1951 - 80 Oregon, Climatography of the United States No. 81 (By State). Stewart. S. and Nelson, D., 1996. Oregon Wellhead Protection Program Guidance Manual. Oregon Department of Environmental Quality (available at http://www.deq.state.or, us/wq/dwp/dwph°me-htm)' Stewart, S. and Nelson, D., 1999. Oregon Source Water Assessment Plan. Oregon Department of Environmental Quality. 17 Drinkin City ,oflSandy Figure 1 Water Protection Area ... Brownell S 3000 0 3000 6000 00 Feet Drinking Water Protection Area (DWPA) 1:30,000 Local Spring Recharge Area Topographic Mapping Method Model Parameters Delineation Area (mi*mi): 2.3 Usage (gal/day): 763,200 Prepared by: AP 11/4/04 Project Manager: JF RG#1867 File # 4100789 OREGON OUADRANGL£ LOCATION N Spring Location: Township 2S Range 5E Section 35 Clackamas County WGS84 Datum: Spring 45°21"34.6,,N 122o9,14.0,,W USGS Chen3mille' OR Quadrangle (part 7.5' s L \ Fig. ure 2: City. of Sandy Potential Contam~nant Sources Scale 1' 30,000 Drinking Water Protection Area (DWPA) Local Spring Recharge Area Topographic Mapping Method 4OOO 8000 Feet Prepared by: KG 1/24/05 Project Manager: AP Reviewed by: DN RG# 1224 File# 4100789 N Potential Contaminant Sources(~ ~Higher Relative Risk ~] Moderate Relative Risk /~ Low Relative Risk Note: Sites and areas noted in this figure are potential sources of contamination to the drinking water identified by Oregon drinking water protection staff. Environmental contamination is not likely to occur when chemicals are used and managed properly. Numbers indicate potential contaminant sources which are explained in the Appendix. QUADRANGLE, LOCATION ,. Figure 3:' City of Sandy Drinking Water SoUrce Susceptibility~ ( Brown.eli 4000 ,0 4000 00 Feet Scale 1'30,000 Drinking Water Protection Area (DWPA) Local Spring Recharge Area Topographic Mapping Method Potential Contaminant Sources (~ Higher Relative Risk [~] Moderate Relative Risk /~ Low Relative Risk Sensitivity Analysis ~ High Soil Sensitivitv ,~ Medium Soil Sensitivity '~ Low Soil Sensitivity Note: Sites and areas noted in this figure are potenital sources of contamination to the drinking water as identified by Oregon Drinking Water Protection Staff. Environmental contamination is not likely to occur when chemicals are used and managed properly. N Features or activities that are identified as high or moderate risk that occur within an area designated as high or moderate sensitivity pose a greater risk to drinking water quality than those in areas of Iow sensitivity. Numbers indicate potential contaminant sources indexed to the Appendix. APPENDIX C -INVENTORY OF POTENTIAL CONTAMINANT SOURCES SANDY, CITY OF - PWS # 4100789 OREGON SOURCE WATER ASSESSMENT Inventory Results Table IA. Summary of Potential Contaminant Sources by Land Use for the Surface Water Source Table lB. Summary of Potential Contaminant Sources by Land Use for the Groundwater Source Table 2. Inventory Results - List of Potential Contaminant Sources Notes for Tables: were..::r~umbered seqUe~t;i:al!'~ .~;itt~: PCS refe:~e~ce ~nu;mbers ;'%J~' ~localed ::i'i~ the surface.:w~ter 'pe ~ie,~: of' the protec.don a.r:ea: a-~d POS' ~(~;fe:re~:~ce ~numbe:rs 5~7 I.ooa:[ed. i'~ ~h'e;:grf~-d:r~:d'~'~'a:[e'r p~f(ioi~s o¢ :the. p~e(e:c~ie.n area, Sites and areas identified in these Tables are only potential, sources of contamination to the drinking water. Environmental contamination is not likely to occur when contaminants are used and managed properly. Total number of sources listed in Table 1 in the DWPA may not add up to the total number of potential contaminants sources in Table 2 because more than one 'type of potential contaminant source may be present at any given facili~. I f'~ ve'~:~te.¢T~' .d,~t:a. ...... · ~ 7 Col.leo~e¢ :.i~ .DS~cem:be~ '2'004:. All de[~¢~ was Acronyms: AST - Aboveground Storage Tank DC - DEQ's Dry Cleaner database DEQ - Oregon Department of Environmental Quality DWPA - Drinking Water Protection Area ECSI - DEQ's Environmental Cleanup Site Information database HW IMSY - DEQ's Hazardous Waste Information Management System database LUST - DEQ's Leaking Underground Storage Tank database NPDES - National Pollution Discharge Elimination System PCS- Potential Contaminant Source PWS - Public Water System SFM - State Fire Marshall's database of hazardous materials SIS - DEQ's Source Information System database (includes WPCF & NPDES permits) SWMS - DEQ's Solid Waste Management System database UST - DEQ's Underground Storage Tank database or Underground Storage Tank WPCF -Water Pollution Control Facility WRD - Oregon Water Resources Division database for water rights information 12/20/2004 TABLE lA. SUMMARY OF POTENTIAL CONTAMINANT SOURCES BY LAND USE FOR SURFACE WATER SOURCE PWS # 4100789 SANDY, CITY OF Residential/Municipal Land Uses Potential Contarn. ination Source Relative Total in - Note Risk Level DWPA Airport - Maintenance/Fueling Area Apartments and Condominiums ._ Higher 0 Ca mpgrounds~RV Parks Lower 0 Cemeteries - Pre- 1945 - -(1) ._ --I~ower' 0 .. Drinking V~ater Treatment Plants ._ -M-oderate 0 Fire Station - . ....... Moderate 0 Fire Training Facilities -. . ......L°v~er 0 Goif Courses ........... 'Moderate 0 Housing - High Density (> 1 House/0.5 acres) Moderate' 0 Landfill/Dumps '~ Moderate 0 Lawn Care__7 .Highly Maintained Areas (1) Higher 0 Motor Pools ..... Moderate 0 __ Parks Moderate 0 Railroad Yar(~'s/Maintenance/Fueling Areas .... Moderate 0 Schools High-er' 0 Septic Systems. High Density ( > 1 system/acre) (~-) .... Lower 0 H!.gher 0 Sewer Lines - Close Proximity to PWS (1) - Higher 0 Utility Stations - Maintenance Transformer Storage Waste Transfer/Recycling Stations Higher 0 Wastewater Treatment Plants/Collection Stations (1) Moderate 0 Other (1) Moderate 0 ._ 0 NOTES: Sites and areas identified in this Table are only potential sources of contamination to the drinking water. Environmental contamination is not likely to occur when contaminants are used and managed properly. (1) - Potential source of microbial contamination (2) - Drip irrigated crops, such as vineyards and some vegetables, are considered lower risk than spray irrigation (3) - For groundwater public water systems, septic systems located within the 2-year time-of-travel (TOT) are considered moderate risks. 12/20/2004 Page 1 of 4 TABLE lA. SUMMARY OF POTENTIAL CONTAMINANT SOURCES BY LAND USE FOR SURFACE WATER SOURCE PWS # 4100789 SANDY, CITY OF Commercial/Industrial Land Uses Relative Total in Potential Contamination .Sou[ce Automobiles - Body Shops Automobiles - Car Washes Automobiles - Gas Stations Automobiles - Repair Shops . Boat Services/Repair/Refinishing Cement/Concrete Plants Che'mical/Petroleum Proce_ssing-/st°rage Dry Cleaners ..... .... Electrical/Electronic Manufacturing Fleet/Trucking/Bus Terminals Food Processing Furniture/Lumber/Parts St0~'es Home Manufacturing J unk/Scra p/Salvage Yards Machine Shops .... MedicaINet Offices Metal Plating/Finishing/Fabrication Mines/Gravel Pits Office Buildings/Complexes Parking Lots/Malls (> 50 Spaces) Photo Processing/Printing Plastics/Synthetics Producer Research Laboratories _. RV/Mini Storage ._ Wood Preserving/Treating Wood/Pulp/Paper Processing and Mills Other Note Risk Level DWPA Higher 0 Moderate 0 Higher 0 Higher 0 Higher- 0'- . __ Moderate 0 Highe-r,' ...... 0 Higher 0 Higher '0 Higher 0 Moderate 0 Moderate 0 . -Higher 0 _.. ._ ~igher 0 Higher 0 Moderate 0 Higher 0 Higher 0 Lower 0 Higher 0 Higher 0 Higher 0 Higher 0 _. Lower 0 Higher 0 ._. Higher 0 0 NOTES: Sites and areas identified in this Table are only potential sources of contamination to the drinking water. Environmental contamination is not likely to occur when contaminants are used and managed properly. (1)- Potential source of microbial contamination (2) Drip irrigated crops, such as vineyards and some vegetables, are considered lower risk than spray irrigation (3) - For groundwater public water systems, septic systems located within the 2-year time-of-travel (TOT) are considered moderate risks. 12/20/2004 Page 2 of 4 TABLE lA. SUMMARY OF POTENTIAL CONTAMINANT SOURCES BY LAND USE FOR SURFACE WATER SOURCE PWS # 4100789 SANDY, CITY OF Agricultural/Forest Land Uses Potential Contamination Source Auction Lots Boarding Stables Confined Animal Feeding Operations (CAFOs) ._ Crops - Irrigated (inc.._.orchards, vineyards, nurseries, greenhouses) Crops - Nonirrigated (inc. C~hristmas trees, grains, grass seed, pasture) Farm Machinery Repair Grazing Animals (> 5 large 'animals or equivalent]acre) Lagoons/Liquid Wastes -- Land Application Sites - Managed Forest Land - B~'oadcast Fertilized Areas Managed Forest Land-- Cle--arCu~t Harvest (< 35 yrs.) Managed Forest Land - Partial Harvest (< 10 yrs.) Managed Forest Land - Road Density ( > 2 mi./sq, mi.) Pesticide/FertilizedPetroleum Storage, Handling, Mixing, & Cleaning Ar Recent Burn Areas (< 10 yrs.) Managed Forest Lands - Status Unknown Other Note (1) (1) (1) (2) (1) (1) Relative Total in Risk Level DWPA Higher 0 _ Moderate 0 Higher ..... 0 Moderate 0 __. Lower 0 Higher -0' Moderate 0 Higher ' 0 Moderate 0 LOwer-' '- 0 Higher 1 Moderate 0 Higher 1 Higher ..... 0 Lowe~: -0 Moderate 0 ._ 0 NOTES: Sites and areas identified in this Table are only potential sources of contamination to the drinking water. Environmental contamination is not likely to occur when contaminants are used and managed properly. (1) - Potential source of microbial contamination (2) - Drip irrigated crops, such as vineyards and some vegetables, are considered lower risk than spray irrigation (3) - For groundwater public water systems, septic systems located within the 2-year time-of-travel (TOT) are considered moderate risks. 12/20/2004 Page 3 of 4 TABLE lA. SUMMARY OF POTENTIAL CONTAMINANT SOURCES BY LAND USE FOR SURFACE WATER SOURCE PWS # 4100789 SANDY, CITY OF Miscellaneous Land Uses Potential Contamination Source Above Ground Storage Tanks - Excluding Water Channel Alterations - Heavy Combined Sewer Outfalls Stormwater Outfalls Composting Facilities Historic Gas Stations Historic Waste Dumps/Lan(~fills .... Homesteads - Rural- Machine Shops/Equipment Maintenance Homesteads- Rural- Septic Systems (< 1/acre) ... Injection/Dry Wells, Sumps - Class V UICs ......... Kennels (> 20 Pens) Military Installations Random Dump Sites ...... River Recreation - Heavy Use (inc. campgrounds) Sludge Disposal Areas Stormwater Retention Basins Transmission Lines - Right-of-Ways Transportation - Freeways/State Highways/Other Heavy Use Roads Transportation- Railroads Transportation - Right-Of-Ways - Herbicide Use Areas Transportation - River Traffic - Heavy ............... Transportation - Stream Crossing - Perennial- __ UST - Confirmed Leaking Tanks - DEQ List __ ._ UST- Decommissioned/Inactive UST - Nonregulated Tanks (< 1,100 gals or Large Heating Oil Tanks) UST - Not Upgraded and/or Registered Tanks UST - Upgraded/Registered - Active UST - Status Unknown Upstream Reservoirs/Dams Wells/Abandoned Wells Large Capacity Septic Systems (serves > 20 'People) - Class V UICs Construction/Demolition Areas Other: - Landslides Relative Total in Note Risk Level DWPA Moderate 0 Lower 0 (1) Lower 0 _. (1) Lower 0 (1) - Mod-~rate 0 _ Higher 0 (1) Higher 0 Higher 0 (1)(3) Lower 0 (1) Higher 0 (1) Lower 0 Higher 0 Higher 1 (1) Lower 0 (1) Moderate 0 (1) Moderate 0 Lower 0 Moderate 0 Moderate 0 Moderate 0 Lower 0 L°-We-~- 0 Higher 0 Lower 0 Higher 0 Higher 0 Lower 0 Higher 0 Lower 0 Higher 0 H) Higher 0 Moderate 0 Moderate 1 NOTES: Sites and areas identified in this Table are only potential sources of contamination to the drinking water. Environmental contamination is not likely to occur when contaminants are used and managed properly. (1) - Potential source of microbial contamination (2) - Drip irrigated crops, such as vineyards and some vegetables, are considered lower risk than spray irrigation (3) - For groundwater public water systems, septic systems located within the 2-year time-of-travel (TOT) are considered moderate risks. 12~20~2004 Page 4 of 4 TABLE lB. SUMMARY OF POTENTIAL CONTAMINANT SOURCES BY LAND USE FOR GROUNDWATER SOURCE PWS # 4100789 SANDY, CITY OF Residential/Municipal Land Uses Potential Contamination Source Airport - Maintenance/Fueling Area Apartments and Condominiums cam-pgro~nds/RV Parks Cemeteries - Pre-1945 Drinking Water Treatment Plants Fire Station Fire Training Facilities Golf Courses Housing - High Density (> 1 House/0.5 acres) Landfill/Dumps Lawn Care - Highly Maintained Areas Motor Pools Parks Railroad Yards/Maintenance/Fueling Areas Schools Septic Systems - High Density ( > 1 system/acre) Sewer Lines - Close Proximity to PWS Utility Stations - Maintenance Transformer Storage Waste Transfer/Recycling Stations Wastewater Treatment Plants/Collection Stations Other Relative Total in _ Note Risk Level DWPA Higher 0 Lower 0 (1) Lower 0 Moderate 0 _ Moderate 0 __ --_. Lower 0 __ .... ..... Moderate 0 __ Moderate 0 .__ Moderate 0 (1) Higher 0 Moderate 0 Moderate 0 _ Moderate 0 _ Higher 0 Lower 0 (1) Higher 0 (1) Higher 0 Higher 0 (1) Moderate 0 (1) Moderate 0 . _ 0 NOTES: Sites and areas identified in this Table are only potential sources of contamination to the drinking water. Environmental contamination is not likely to occur when contaminants are used and managed properly. (1) - Potential source of microbial contamination (2) -. Drip irrigated crops, such as vineyards and some vegetables, are considered lower risk than spray irrigation (3) - For groundwater public water systems, septic systems located within the 2-year time-of-travel (TOT) are considered moderate risks. 3/2 34 Page I of 4 TABLE lB. SUMMARY OF POTENTIAL CONTAMINANT SOURCES BY LAND USE FOR GROUNDWATER SOURCE PWS # 4100789 SANDY, CITY OF Commercial/Industrial Land Uses Relative Total in Potential Contamination Source Automobiles - Body Shops Automobiles - Car Washes Automobiles -Ga~-'Stations Automobiles- Repair-shops Boat Services/Repair/Refinishing Cement/conCrete Plants (~hemical/Petroleum ProCessing/Storage .... Dry Cleaners Electrical/Electronic Manufacturing Fleet/T-~ucking/Bus Terminals Food Processing Furniture/Lumber/~arts Stores Home Manufacturing Junk/Scrap/Salvage Yards Machine Shops MedicalNet Offices Metal Plating/Finishing/Fabrication Mines/Gravel Pits Office Buildings/Complexes Parking Lots/Malls (> 50 Spaces) Photo Processing/Printing Plastics/Synthetics Producer Research Laboratories RV/Mini Storage Wood Preserving/Treating Wood/Pulp/Paper Processing and Mills Other Note Risk Level DWPA Higher 0 Moderate 0 Higher 0 Higher 0 Higher 0 Moderate 0 'Higher" 0 _.. Higher 0 Higher 0 Higher 0 Moderate 0 Moderate 0 Higher 0 Higher 1 Higher 0 Moderate 0 Higher 0 Higher 0 Lower 0 Higher 0 Higher 0 .... Higher 0 Higher 0 Lower 0 Higher 0 Higher 0 0 NOTES: Sites and areas identified in this Table are only potential sources of contamination to the drinking water. Environmental contamination is not likely to occur when contaminants are used and managed properly. (1) - Potential source of microbial contamination (2) - Drip irrigated crops, such as vineyards and some vegetables, are considered lower risk than spray irrigation (3) - For groundwater public water systems, septic systems located within the 2-year time-of-travel (TOT) are considered moderate risks. 12/20/2004 Page 2 of 4 TABLE lB. SUMMARY OF POTENTIAL CONTAMINANT SOURCES BY LAND USE FOR GROUNDWATER SOURCE PWS # 4100789 SANDY, CITY OF Agricultural/Forest Land Uses Potential Contamination Source - Note Auction Lots Boarding Stables - (1) Confined Animal Feeding Opera-tions (CAFOs) (1-) Crops - Irrigated (inc. orchardsi-~;~eyards, nurseries, greenhouses) (2)' Crops - Nonirrigated (inc.-c-hristmas trees, grains, grass seed, pasture) Farm Machinery R~pair Grazing Animals (> 5 large animals or equivalent/acre) (1) Lagoons/Liquid wa-~tes - .--. (1) Land Application Sites (1~ Managed Forest L~nd. ~roadcast Fertilized Areas Managed Forest Land - Clearcut Harvest (< 35 yrs,)- ..... Managed Forest Lar~d --~a'~tial Harvest (< 10 yrs.) Managed Forest Land 'R~ad Density ( > 2 mi./sq, mi.) Pesticide/Fertilizo-~Petr°~um Storage, Handling, Mixing, & Cleank~ Ar Recent Burn Areas (< 1~ yrs.) Managed Forest Lands --Status Unknown Other - __. Relative Total in Risk Level DWPA Higher 0 Moderate 0 _ Higher 0 Moder~a~e 0 'Lowe[ 0 Higher 0 Moderate '0 __. Higher 0 Modera:~e 0 --Lower-- 0' Moderate 1 Uod~'-~te 0 Moderate 0 Higi~'r-- 0 Lower 0 Moderate 0 0 NOTES: Sites and areas identified in this Table are only potential sources of contamination to the drinking water. Environmental contamination is not likely to occur when contaminants are used and mana ged properly. (1) - Potential source of microbial contamin ation (2) - Drip irrigated crops, such as vineyards and some vegetables, are considered lower risk than spray irrigation (3) - For groundwater public water systems, septic systems located within the 2-year time-of-travel (TOT) are considered moderate risks. 12/20/2004 Page 3 of 4 TABLE lB. SUMMARY OF POTENTIAL CONTAMINANT SOURCES BY LAND USE FOR GROUNDWATER SOURCE PWS # 4100789 SANDY, CITY OF Miscellaneous Land Uses Relative Total in Potential Contamination Source Above Ground' Storage Tanks - Excluding Water Channel Alterations - Heavy Combined Sewer Outfalls Stormwater Outfalls Composting Facilities Historic Gas Stations . . Historic Waste Dumps/Landfills Homesteads - Rural- Machine-Shops/Equipment Maintenance Homesteads - Rural - Septic SYstems (< 1/acre) Injection/Dry Wells, SumPs - Class V UlCs Kennels (> 20 Pens) Military Installations Random Dump Sites River Recreation - Heavy Use (inc. campgrounds) Sludge Disposal Areas Stormwater Retention Basins Transmission Lines- Right-of-Ways Transportation - Freeways/State Highways/Other Heavy Use Roads Transportation - Railroads Transportation - Right-Of-Ways - Herbicide Use Areas Transportation - River Traffic- Heavy Transportation - Stream Crossing - Perennial UST - Confirmed Leaking Tanks - DEQ' List UST - Decommissioned/Inactive UST - Nonregulated Tanks (< 1,100 gals or Large Heating Oil Tanks) UST - Not Upgraded and/or Registered Tanks UST - Upgraded/Registered - Active UST - Status Unknown Upstream Reservoirs/Dams Wells/Abandoned Wells Large Capacity Septic Systems (serves > 20 people) - Class V UICs Construction/Demolition Areas Other Note Risk Level DWPA Moderate 0 ._ Lower 0 __ (1) Lower ~ .... (1) Lowe~' 0 _ _ (1) Moderate 0 Higher 0 (~) .Highe~ --0 Higher 0 (1)(3) Lower 1 H) Higher 0 (~) Lower 0 _ Higher 0 Moderate 0 (~) Lower 0 (~) Moderate 0 (1) Moderate 0 Lower. 0 Moderate 0 Moderate 0 Moderate 0 _. Lower 0 Lower 0 Higher 0 Lower .... -0 Higher 0 Higher 0 Lower 0 Higher 0 Lower 0 Higher 0 (~) Higher 0 Moderate 0 0 NOTES: Sites and areas identified in this Table are only potential sources of contamination to the drinking water. Environmental contamination is not likely to occur when contaminants are used and managed properly. (1) - Potential source of microbial contamination (2) - Drip irrigated crops, such as vineyards and some vegetables, are considered lower risk than spray irrigation (3) - For groundwater public water systems, septic systems located within the 2-year time-of-travel (TOT) are considered moderate risks. 12/20/2004 Page 4 of 4 U.I Z I-- Z UJ I-- o 0 ! o Z Z U.I Z Z § o o CLAC 57844 · ! STATE OF OREGON WATER SUPPLY WELL REPORT (u r~qu~d by O~S l~r~ctiona for ~lefing~is ~p~ n~ on ~e I~t ~a~ ~f thi~ form. (x) o~ c~ ~'~~ - s~ 0<~ z~ ~ (3) D~LLM['rHOD: HO~ SE~ Worded TkreMhd M,~cri~ T.W~ (8) WELLTESTS: Minimum testing time is I hour Flowing Yield ll~/lldl ~)rlwdowm DFIJ] felt3 el 'rhT~e Tcr~ocra~c ~ water_,..~'.~ Dcpth Artesian Flow Found Liner [] [] [] START CA~ # .i 3 / 7o ~' (9) LOCATION OF WELL by I~1 description: County ~.~,vt~l_.~ L~tude Longitud~ smi~ 'b $ ~ I/4/K [,/. Tax Lot ~ Lot~ Block Subdivision Slreet A~lrcss of Well (or nearest addrets) ~sim lxessure lb. per square inch. D=*,, ' _ (11) WAi'ER BEARING ZONES: ' Depth at which waif was tim found ~, 0 From To Estin~ted Flow (12) WELL LOG: Grmmd l~ev~tion Complctcd (unbonded) Water Well Constructm- Certification: kie~i~ts u~l '-'-~'-"-'~'?~-'~--' :. ,-.=g .on ?atcr supply wen construction standards. mm truorm~otl I~ ~ove ~ and belief, port~ e to the best of my knowledge WWC Number ~igne. A _.~. D~ (bonded) Water Well Cm~ructor Certification: ~d~Y s~~ w~t ~i~ie f~ ~u~? ~ T~ li~le ~[~ ~n~s~ii.p~g.~e~~s re~~vc. Allw~ ] ~.~o ~g ~s t~c u m ~im~ wi~ ~cg~ w~ su~ly wcU ORIGINAL & FIRST COPY-WATER RESO~C~ DEPARTM~ SECOND ~PY*CONSTRU~OR THI~: COP Y-CU3~M~ ' Parameters Used in Delineation Model Delineation Method: [] Numerical [] Hydrogeologic Mapping [] Analytic Element [] Other: Topographic Mapping ,,. Flow Rate (Q in gpm): ~400 gpm according to Leonard and Collins (1983}, ~530 gpm according to 1999 Sanitary. Survey. Source: [] System [] Water Resources Dept [] Other:_Sanitary Survey Nature of the Aquifer: [] Unknown [] Semi-confined [] Unconfined [] Confined Aquifer name: Layered Volcanics (Boring LaVa) Confining Unit lithology: Depth to Confining Unit: Confining Unit thickness: Depth to Aquifer: NA NA NA <100 feet Aquifer Characteristics: Lithology: [] Unknown [3 Sand [] Gravel [] Other: [] Sandy Silt [] Sand & Gravel [] CBbbles/Gravel [] Layered Volcanic Rocks [] Fractured Volcanic Rocks [] Fractured Sedimentary Rocks Geologic Factors Controlling Spring: [] Impermeable Contact [] Volcanic Interflow Zone [] Fractures [] Perched Spring [] Other El Unknown Hydraulic Conductivity (Permeability): fi/day [] N/A [] Estimated from lithology [] Specific Capacity (from a nearby Well Report) [] Published Report [] Aquifer Test Hydraulic Gradient: [] Published Report [] Field Measurements Flow Direction: [] Graphical Solution [] Model Results [] N/A [] Estimate High Capacity Wells Accounted for: None