Source Water Delineation and Assessment Report

SOURCE WATER DELINEATION AND ASSESSMENT REPORT

Kila School District # 20 Public Water System Flathead County

PWSID # MT0000892

Date of Report: December 04, 2006 Report Review Date: January 3, 2007 By Jim Stimson DEQ Source Water Protection Program

Tina Malkuch Certified Operator 1500 Airport Road Kalispell, MT 59901

Phone: (406) 752 4949

Prepared By Rachel Giblin (Student Intern) and Dr. Steve Custer Montana State University Bozeman, MT 59717-3480 PH: 406 994 6906

EXECUTIVE SUMMARY ...... 4

INTRODUCTION ...... 7

CHAPTER 1 - BACKGROUND ...... 8 THE COMMUNITY ...... 8 GEOGRAPHIC SETTING ...... 8 GENERAL SOURCE WATER DESCRIPTION...... 9 PUBLIC WATER SUPPLY ...... 10 WATER QUALITY ...... 11 Table 1a. Regional water quality data for Ravalli Group aquifer in Kila area ...... 13 Table 1b. Regional water quality for Ravalli Group aquifer, continued ...... 13 Table 2a. Regional water quality for Middle Belt Carbonate aquifer in Kila area ...... 14 Table 2b. Regional water quality for Middle Belt Carbonate aquifer in Kila area ...... 14

CHAPTER 2 - DELINEATION ...... 15 HYDROGEOLOGIC CONDITIONS ...... 15 Table 3. List of geologic maps available for the Kila area...... 15 LOCAL HYDROGEOLOGIC SETTING ...... 16 CONCEPTUAL MODEL AND ASSUMPTIONS ...... 17 Table 4. List of hydrogeologic investigations for the Kila area...... 18 Title of Project ...... 18 WELL INFORMATION ...... 18 LIMITING FACTORS ...... 19

CHAPTER 3 - INVENTORY ...... 20 INVENTORY METHOD ...... 20 INVENTORY RESULTS/CONTROL ZONE ...... 21 INENTORY RESULTS/INVENTORY REGION ...... 21 Table 6. Underground storage tanks in the recharge region listed with the Montana DEQ...... 22 Table 7. Leaking underground Storage Tanks listed with Montana Department of Environmental Quality...... 23 INVENTORY RESULTS/RECHARGE REGION ...... 23 INVENTORY UPDATE ...... 23 INVENTORY LIMITATIONS ...... 23

CHAPTER 4 - SUSCEPTIBILITY ASSESSMENT ...... 24 Table 8a. Relative susceptibility to specific contaminant sources as determined by hazard and the presence of barriers...... 25 Table 8b. Hazard of potential contaminant sources for unconfined aquifers...... 25

REFERENCES ...... 28

APPENDICES ...... 31 APPENDIX A - FIGURES ...... 32 Figure 1. Kila vicinity map. Blue square indicates Kila public water supply (PWS) ...... 33

Figure 2. Private and public water supply wells and potential contaminant sources in the general location of Kila ...... 34 Figure 3. Digital orthophotos of Kila Inventory (upper photo) and Control (lower photo) Zones. Arrows indicate direction of groundwater flow...... 35 Figure 4. Kila Recharge Region. Arrows indicate direction of groundwater flow...... 36 Figure 5. Montana Geologic Map and Kila Vicinity Geology (U.S. Geological Survey, 1998). Kila PWS= ...... 37 Figure 6. Altitude of and Depth to the Bedrock Surface, Kila area (Smith, 2000) ...... 38 Figure 7. Example of bedrock fracturing in the Belt Supergroup common for the Kila area. Belt rocks underlie the Salish Mountains at Kila. F1 and F2 are two sets of fractures in this roadcut. DH are drillholes used to expose the roadcut that are analogous to water wells that intersect subsurface fractures. Location: T 27 N, R 21 W, sec 6 (Patton et al., 2003)...... 39 Figure 8. Kila Land Use Inventory Zone ...... 40 Figure 11. Land Use percentages for Kila’s Recharge Region ...... 43 Figure 12. Potentiometric surface map of the Kila area and part of Flathead Valley (LaFave, 2000)...... 44 APPENDIX B - Site Plan ...... 46 APPENDIX C - Well Log and Well Log Report...... 47 APPENDIX D - Lithologic Well Logs for Wells with Water Quality Data . Error! Bookmark not defined. APPENDIX E – DEQ Water Quality Monitoring Data ...... 54 APPENDIX F - Sanitary Surveys ...... 55 APPENDIX G - Hazard and Barrier Worksheets ...... 56

EXECUTIVE SUMMARY By Jim Stimson December 18, 2006

Introduction and Background

Kila School District 20 is located in Flathead County about 11 miles southwest of Kalispell (Appendix A, Figures 1, 2, and 3). According to the most recent sanitary survey, the school serves about 145 students and 24 staff during the school year. The school’s public water supply is classified as a non-transient non-community system which means it serves the same population for more than six months of the year.

Groundwater is the source of water for the school and comes from a single well located on the southwest corner of the school property. The well is 440 feet deep with a static water level of 103 feet and a pumping water level of 415 feet. The well yielded 16 gallons per minute during an 7 hour well test. Six-inch diameter casing extends to 115 feet below the land surface and 4.5 inch pvc casing extends to the bottom of the well. Perforations extend from 420 to 440 feet and the well is sealed to a depth of 20 feet from the land surface.

According to the driller’s log, the school’s active well is completed in fractured bedrock. Logs from other wells in the area indicate that 40 to 214 feet of unconsolidated sediments overlie the bedrock. Many of these logs record multiple and relatively thick clay- dominated layers above the bedrock contact. The clay-dominated layers are interpreted in this report to help seal the well and confine the aquifer. Many of the wells in the area, including the wells located on the school’s property, yield relatively small volumes of water with substantial water level drawdown. Drawdown is often on the order of 200 to 300 feet. This indicates that the fractured bedrock aquifer does not transmit water efficiently and does not appear to have efficient access or connection to sources of water recharge. Based on the driller’s logs and well performance, the aquifer serving the school is interpreted to be locally confined with relatively low hydraulic conductivity. A deep confined aquifer is considered to have a low sensitivity to potential contaminant sources located at or near the land surface.

Public water systems must conduct routine monitoring for contaminants in accordance with Federal Safe Drinking Water Act requirements. A non-transient public water supply, like Kila School, must sample in accordance with schedules specified in the Administrative Rules of Montana (ARM). Within the past five years, Kila School has not had any positive total coliform bacteria samples. There was an episode of positive bacteria samples prior to 2000 but that episode appears to have been related to issues with replacement of a pump or perhaps other parts of the water distribution system. Since 2000, the school’s bacteria monitoring history has been very good. No maximum contaminant level (MCL) exceedances were noted for any other constituents monitored at the school over the past five years, this includes nitrate. The highest nitrate value for the school is 0.18 milligrams per liter (mg/L). This value is significantly below the maximum contaminant level (MCL) of 10 mg/l set by the EPA.

Delineation of Source Water Protection Areas

The purpose of delineation is to map the source of drinking water for the public water supply and to define areas within which to prioritize source water protection efforts. Three source water protection areas are defined for the school (Figures 2, 3 and 4). They include a 100-foot control zone around the well, a one-mile fixed radius inventory region, and a recharge region generally corresponding to portions of the local watershed surrounding the public water supply.

Source water for the school’s well comes from a deep (>100 feet) fractured bedrock aquifer that is overlain by a mantle of glacial deposits ranging in thickness from 40 to 200 feet or more. The glacial deposits overlying the bedrock consist of a complex mixture of clay, silt, sand and gravel. Water that recharges the aquifer used by the school is interpreted to come from land areas generally west of the well site (Appendix A – Figure 4). Recharge comes from a combination of precipitation, snowmelt runoff, irrigation water applied to fields, and leakage from streams, lakes, and irrigation canals. Groundwater flow direction is shown to be primarily from upland areas towards lowlands and streams (Figures 12 and 13). In the vicinity of the school this means groundwater is flowing generally from the west-northwest to the east-southeast and toward Smith Lake and Ashley Creek. Near Ashley Creek, groundwater flow is interpreted to move parallel with the creek valley to the northeast.

Inventory of Potential Contaminant Sources

The inventory is used to assess the susceptibility of the Kila School’s public water supply to contamination and to identify priorities for source water protection planning. The inventory focuses on facilities that generate, use, store, transport, or dispose of potential contaminants and on land types where potential contaminants are present. Maps of the inventory results are shown in Figures 2, 3, 4, 8, and 9.

Susceptibility is the potential for a public water supply to draw in water contaminated by inventoried sources. Susceptibility is determined by considering the hazard rating for each potential contaminant source and the existence of natural or man-made barriers that decrease the likelihood that contaminated water will flow to the public water supply well (Tables 8a and 8b). Table 9 lists all of the potential contaminant sources identified in this inventory and includes the hazard and final susceptibility ratings assigned to each potential contaminant source.

Kila School is located in a fairly rural and undeveloped part of the county. As a result, there are not a lot of potential contaminant sources within the inventory region. Potential contaminant sources that could pose a threat to the public water supply include: the school’s on-site, large capacity septic system and service lines, other wells on the school grounds, weed and pest control efforts at the school and on the grounds, agricultural land, septic systems on adjacent developed land parcels and local roads. Figures 2, 3, 4, 8, and 9 show the locations of potential contaminant sources in relation to the public water supply. The school’s on-site large capacity septic system and other wells on the school grounds are assigned moderate susceptibility ratings. Moderate is the highest rating

5 assigned to any potential contaminant sources within the inventory region. The ratings are set at this level due to the fact that the septic system and its components are relatively close to the school’s well and water distribution lines, and the other wells are completed essentially in the same aquifer as the active well. The wells could act as direct conduits into the aquifer for any contaminants used or spilled in the vicinity of the unused wells. While the school’s water quality monitoring data does not indicate that the source water is being impacted by these potential contaminant sources (Appendix F), it is advisable to take steps to reduce the hazard these sources pose to the public water supply. It may be possible to lower the risk and susceptibility rating for the septic system by moving the drainfield farther from the well (well beyond 100 feet) to land areas east of the well. This would place the drainfield in a down-gradient location from the well. Down-gradient means that groundwater beneath these land areas is moving away from the well and not toward it. Susceptibility for the other school wells could be lowered by properly abandoning both wells. This is usually accomplished removing all connections to the water distribution system and filling the wells completely with cement. For more detailed discussion of the potential contaminant sources identified within the inventory region please refer to Chapter 3 and the inventory results that begin on page 21.

Table 9 lists all of the potential contaminant sources identified in this inventory that are considered significant and includes the final susceptibility ratings. It is important to understand that all of the potential contaminant sources may not have been identified in this inventory. In some instances, inadequate location information in the available databases can result in some potential contaminant sources not being included in the inventory, as can undocumented spills or releases or illegal dumping of hazardous materials within the inventory region. The certified operator is encouraged to maintain and update the inventory for this public water supply on an annual basis and provide an updated inventory to DEQ every 5 years.

Management Recommendations

It should be noted that even small releases of some chemicals in close proximity to a well could have significant negative impact on water quality. Steps can be taken to reduce the likelihood of contaminant releases to the source water or in the vicinity of the well. Some of these steps are listed in Chapters 3 and 4, and are included in Table 9.

INTRODUCTION

This report is intended to meet the technical requirements for the completion of the Source Water Delineation and Assessment for Kila School District #20 Public Water Supply System (PWS ID: MT0000892) as required by the Montana Source Water Protection Program and the Federal Safe Drinking Water Act (SDWA). The Delineation and Assessment Report (SWDAR) for the Kila School District was completed by MSU student Rachel Giblin under the supervision of Dr. Steve Custer, at Montana State University. This report was reviewed and edited by Jim Stimson, a hydrgeologist with the Department of Environmental Quality’s Source Water Protection Program. The executive summary was written by Jim Stimson.

The Montana Source Water Protection Program is intended to be a practical and cost- effective approach to protecting public drinking water supplies from contamination. A major component of the Montana Source Water Protection Program is termed delineation and assessment. The emphasis of this delineation and assessment report is identification of significant potential contaminant threats to public drinking water sources and provision of the information needed to develop a source water protection plan for Kila School District.

Delineation is a process whereby areas that contribute water to aquifers or surface waters used for drinking water, called source water protection areas, are identified on a map. Geologic and hydrologic conditions are evaluated in order to delineate source water protection areas. Assessment involves identification of locations or regions in source water protection areas where contaminants may be generated, stored, or transported and then determination of the potential for contamination of drinking water by these sources.

The SWDAR is the first step in source water protection for a public water supply and the surrounding community. A Source Water Protection Plan is the next step in this process and although voluntary, it is an important part of protecting the source water for future use. If the Public Water Supply is interested in developing a plan, the water operator is encouraged to contact the DEQ Source Water Protection Program.

CHAPTER 1 - BACKGROUND

THE COMMUNITY

The Kila School is in Flathead County, in the town of Kila, Montana. The population of Flathead County according to Census estimates for 2003, is 79,485. Agriculture, construction, manufacturing, retail trade, educational, health and social services, arts, entertainment, recreation, accommodation and food services make up the major industrial bases for Flathead County. The population of Kila is 742 (Census, 2003). Surrounding cities include Kalispell approximately 11 miles northeast on Route 2 and Marion is approximately 11.6 miles to the west on Route 2 (Appendix A, Fig. 1).

The lake and marsh in the Smith Lake Valley occupy a glacially scoured depression where Ashley Creek both empties into and flows out of Smith Lake (Appendix A, Fig. 1). Smith Lake is surrounded by wetlands that serve as temporary surface water storage areas during peak flows of Ashley Creek. Surface water gradually drains from the marshes and maintains Ashley Creek stream flow later in the summer (NRIS, 2004).

Kila School is classified as a non-transient non-community public water supply system because it regularly serves at least 25 of the same persons over six months, but less than 12 months per year. The school is served by an on-site septic system that is classified as a large capacity septic system because it serves more than 20 persons per day. The drainfield is near the school’s playground approximately 100 feet west of the school’s gymnasium. The well is shown to be about 200 feet or more southwest of the gym. Based on this information it appears that the drainfield is located outside of the active wells 100-foot control zone and is in a cross-gradient location relative to the well. This means that groundwater beneath the drainfield location is moving generally parallel to the well and not towards it. The importance of the cross-gradient location is discussed further in Chapter 3. The playground is fenced with a 4 foot chain link fence. The septic system serves approximately 145 students (kindergarten through grade 8) and a 24 person staff. The school is active as a public water supply from September 1 to June 15. The school facilities are generally not used throughout the summer months.

GEOGRAPHIC SETTING

Kila and the school are located within the Glaciated Northern Rocky Mountains physiographic province (Howard and Williams, 1972) and the western mountain ranges ground-water region of the United States (Heath, 1984). Kila is in the Smith Valley and at an elevation 3,177 feet above sea level. The valley is bounded by the Salish Mountains. Ashley Creek flows northeast to Smith Lake (Appendix A, Fig. 1). There are many smaller tributaries including Truman Creek, Mount Creek and Boorman Creek in the area. The school is in the Flathead Lake Watershed, hydrologic unit code# 17010208 (US EPA, 2003).

Climate data for the area is collected from the NRCS National Water and Climate Center online database, from the Kila weather station 1500 feet west of Highway 2. Kila has a

8 relatively dry climate and steep, rocky soils (US EPA, 2003). The average low and high temperatures for Kila are 14.7, and 31.1 degrees Fahrenheit in January. In July, the average low and high temperatures are 45.7 and 83.8 degrees Fahrenheit. Kila receives 15.31 inches of precipitation and 47.4 inches of snowfall annually.

GENERAL SOURCE WATER DESCRIPTION

Kila School Wells: Groundwater is the source of drinking water for Kila School District. There is one active well and one abandoned well on the Kila School grounds (Malkuch, 2005). In the effort to replace the school’s old well two wells were drilled but only one had sufficient production to meet the school’s water demands. The other well was cemented in and is considered to be abandoned.

The MBMG Groundwater Information Center (GWIC) database lists four wells as belonging to the school. The well record with GWIC ID 144874 appears to be an incomplete record for the school’s active well (GWIC ID 139464). GWIC lists two additional wells belonging to the Kila School District. The other wells shown for the school district in GWIC are considered to be unused or abandoned and are not discussed in detail in this report. If additional information on the other wells is or becomes available, the DEQ and the MBMG should be notified so that the MBMG database and this Source Water report adequately reflect the current well status.

The active well (GWIC ID# 139464) is in a grassy field on the southwest corner of the property and is sealed from run off. According to the operator, a test well (GWIC ID# 139465) was drilled on September 21, 1993 that later became the active well. The active well (GWIC ID# 139464) was drilled to a depth of 440 feet, has a static water level of 103 feet, and a pumping water level of 415 feet. A yield of 16 gallons per minute is reported on the driller’s log for a 7 hour well test. This is the only well currently serving the Kila School (Malkuch, 2005). The well log for the active well (GWIC ID# 139464) is included in Appendix C of this report.

According to the operator, the decimal coordinates listed by GWIC for the test well are those of the abandoned well (GWIC ID# 81140). The correct coordinates of the test well are recorded with the active well (GWIC ID# 139464) although the test well was drilled to 500.00 feet and the active well was drilled to 440.00 feet. The abandoned well (GWIC ID# 81140) is in a gravel parking lot 200 feet south of the gymnasium. It is on the southwest corner of a four foot fence bordering the playground with decimal degree coordinates latitude 48.1193, longitude -114.4573. The parking lot is graded away from the well and has been restricted to use. It was drilled to a depth of 690 feet, has a static water level of 100 feet, and a pumping water level of 300 feet. According to the well log listed with GWIC, it was drilled on March 6, 1981. This older, inactive well has not been abandoned properly although it has been physically disconnected from the system. The school intends to keep the well available for future use if necessary. The well log for GWIC ID #81140 is included in Appendix C of this report. Both the active and abandoned wells have proper well caps.

PUBLIC WATER SUPPLY

There is one well supplying groundwater to the Kila School (GWIC ID# 139465). The well serves 145 students (K-8th grade) with a 24 person staff (Environmental Health Services, 2000). Seasonal operation is between the dates of September 1 and June 15. Using the U.S. EPA Manual of Small Public Water Supply Systems, the average daily usage is estimated to be 3,625 gallons per day (U.S. EPA, 1991).

Present average daily production capacity is 1,500 gallons per day with a total design production capacity of 15,000 gallons per day. Maximum daily production is 2,500 gallons per day (Sanitary Survey - Flathead County Environmental Health Services, 2000). The average well yield for wells within the Bedrock Aquifer is 18 gpm (maximum 850gpm) (Patton et al., 2003). According to Flathead County Environmental Health Services, the recommended production rate for well #139465 is 10gpm (maximum 12gpm).

The active well is cased with 6 inch diameter steel pipe to a depth of 115 feet and 4.5 inch plastic to the bottom of the hole. There is a 10” steel outer casing from the ground surface to a depth of 20’ and the well is grouted with bentonite to that depth. The casing has factory made perforations from 420 to 440 feet. The well pump is a Fairbanks Morse Mod. 3D20027, 2HP submersible and is able to charge two Champion Mod 053306460 captive air tanks from 40 psi to 60 psi (about 30 gallons of water) in 3.5 minutes (Sanitary Survey - Flathead County Environmental Health Services, 2000). Since there are two pressure tanks, Environmental Health Services (2000) recommends isolation valves be installed. In case of emergency, the isolation valves would allow each tank to be serviced or replaced without having to depressurize the entire system. The valves have not been installed yet (Malkuch, 2005).

According to the operator, a frost-free hydrant was installed about a foot away from the well. It is used in case of emergency and can flush or chlorinate the system if necessary. It was used in late August of 2000 when a driller changed a pump and accidentally injected a contaminant into the well. The problem was attended to and the system was flushed for about three months. By mid-December of 2000, the system was clean (Malkuch, 2005).

According to the operator, the drainfield is about 100 feet north of the well, which as noted previously is interpreted as being outside of the wells control zone and is in a cross- gradient location. A contractor built the drainfield over the main water line that used to supply the school with water. The water line was re-directed around the drainfield. Currently, the main line is 10 to 12 feet from the drainfield along its west side and south end. It is in proper working condition and has never had any problems. The main line continues into the gymnasium building where there is a softener and pressure tanks. There is a gate valve located in line between the well and the pressure control switch. Problems could arise if the valve is closed without shutting off the pump’s electricity. The most recent sanitary survey recommended this valve be removed from the system to prevent the pump from burning out (Flathead County Environmental Health Services

(2000). Although the valve has not been removed, the operator attended to the matter by noting that the power to the well needs to be shut off prior to closing the valve.

A second well in the southwest corner of the Kila School property (latitude 48.1193, longitude -114.4573, GWIC ID# 81140) has been removed from the system but not abandoned. It has a well cap and the school intends to keep it available for future use in an emergency (Malkuch, 2005).

WATER QUALITY

Background Water Quality: Available regional background water quality for the Middle Belt Carbonate (400MCRB) and Ravalli Group (400RVLL) aquifers in the area of the Kila School is presented in Table 1 and 2 respectively (Montana Bureau of Mines and Geology, GWIC). These aquifers were selected based on GWIC’s water quality data and the geologic framework of hydrologic units in the Flathead Lake area ground-water characterization study within Flathead, Lake, Sanders, and Missoula Counties (Smith, 2000). The GWIC database was searched for water quality data downstream and upstream from Kila along Ashley Creek to its confluence with the Flathead River south of Kalispell (Appendix A, Fig. 1).

There are six water quality records for wells specified as completed in the Ravalli Group. Specific electrical conductivity at 25 °C had an average value of 304.5 micromhos/cm, with a low of 15.0 micromhos/cm and a high of 681.0 micromhos/cm. Total dissolved solids (TDS) values are all under 380.02 mg/L. Data indicates that the water is bicarbonate (HCO3) and calcic (Ca), but is not overly abundant in any one cation. The pH values range from 6.4 to 7.8 (average=7.21).

There are six water quality records for wells specified as completed in the Middle Belt Carbonate within the search area. Specific electrical conductivity at 25 °C had a average value of 451.37 micromhos/cm, with a low of 375.26 micromhos/cm and a high of 636.26 micromhos/cm. Total dissolved solids (TDS) values are all under 452.08 mg/L. The median dissolved constituent concentration for Belt Supergroup aquifers is 375 mg/L. Data indicates that the water is bicarbonate (HCO3) and calcic (Ca), but is not overly abundant in any one cation. The pH values range from 7.3-7.9 (average=7.74).

Public Water Supply Water Quality Monitoring: The Kila School PWS is routinely monitored for compliance with drinking water standards. Bacteriological monitoring occurs monthly. Compliance with other drinking water standards is based on additional sampling on a variety of schedules depending on system classification and population served. Sampling and monitoring includes nitrate which can come from human or animal wastes and can occur naturally. The highest nitrate level detected in the Kila School well in the last five years occurred as nitrate + nitrite (as N) at 0.18 milligrams per liter (mg/L) on February 5, 2002. This value is well below the maximum contaminant level (MCL) of 10 mg/L set by the U.S. EPA.

Prior to December 2000, Kila School had tested positive for bacteria multiple times. According to the operator, the contamination may have been associated with inadequate

11 disinfection of the well following replacement of the well pump. The operator continued to periodically disinfect and flush the system to attend to the matter. The system has not recorded any bacteria detects in the last five years (DEQ, 2007). DEQ water quality reports are included in this report in Appendix E.

Table 1a. Regional water quality data for Ravalli Group aquifer in Kila area GWIC ID Aquifer Latitude Longitude Location (TRS) Ca (mg/l) Mg (mg/l) Na (mg/l) K (mg/l) Cl (mg/l) HCO3 (mg/l) 137653 400RVLL 48.0416 -114.8719 26N, 25W, 6 10.6 3.3 15 0.9 2 72.7 141665 400RVLL 48.2572 -114.4511 29N, 22W, 19 67.8 33.6 28.7 0.545 7.47 436 45316 400RVLL 48.2308 -114.4183 29N, 22W, 32 22 18 19 0.53 2.7 183.2 6426 400RVLL 48.1974 -114.3716 28N, 22W, 11 22 702957 400RVLL 48.3055 -114.3275 29N, 21W, 6 56 12.4 19.2 1 3.8 262.6 81319 400RVLL 48.1363 -114.9594 27N, 26W, 4 18.8 5 26 1 4 151.5 MAX 67.8 33.6 28.7 1 7.47 436 MIN 10.6 3.3 15 0.53 2 72.7 AVERAGE 32.87 14.46 21.58 0.795 3.10 221.2

Table 1b. Regional water quality for Ravalli Group aquifer, continued SO4 SiO2 GWIC ID Aquifer CO3 (mg/l) NO3 (mg/l) F (mg/l) Fe (mg/l) Lab pH Lab SC TDS (mg/l) (mg/l) 137653 400RVLL 0 12 <.05 P <1. 54.4 0.079 6.4 151 134.4 141665 400RVLL 0 <25.0 .624 P <.5 26.4 <.025 7.44 681 380.02 45316 400RVLL 0 16 .18 P <1. 32.8 <.003 7.3 325 201.56 6426 400RVLL 0 33 7 15 702957 400RVLL 0 8 .3 P <1. 13.9 0.011 7.8 427 244.01 81319 400RVLL 0 <2.5 .29 P <1. 31.1 1.4 7.3 228 163.02 MAX 0 33 0 0 54.4 1.4 7.8 681 380.02 MIN 0 8 0 0 13.9 0.011 6.4 15 134.4 AVERAGE 0 17.25 31.72 0.496667 7.206667 304.5 224.602 Table 2a. Regional water quality for Middle Belt Carbonate aquifer in Kila area Na HCO3 GWIC ID Aquifer Latitude Longitude Location (TRS) Ca (mg/l) Mg (mg/l) K (mg/l) Cl (mg/l) (mg/l) (mg/l) 130553 400MCRB 48.0797 -114.2422 27N, 21W, 26 148194 400MCRB 48.3204 -114.3897 30N, 22W, 34 47.8 18.6 15.3 1.9 0.5 277.2 148194 400MCRB 48.3204 -114.3897 30N, 22W, 34 47.4 18.6 15.2 1.9 0.05 291.8 6397 400MCRB 48.0669 -114.2383 27N, 21W, 26 116 26.9 17.2 0.8 57 363 80915 400MCRB 48.1238 -114.2644 27N, 21W, 10 54 17.6 9 0.877 4.1 270.8 83195 400MCRB 48.1891 -114.4813 28N, 23W, 14 MAX 116 26.9 17.2 1.9 57 363 MIN 47.4 17.6 9 0.8 0.05 270.8 AVERAGE 66.3 20.425 14.175 1.36925 15.4125 300.7

Table 2b. Regional water quality for Middle Belt Carbonate aquifer in Kila area GWIC SO4 SiO2 Fe Aquifer CO3 (mg/l) NO3 (mg/l) F (mg/l) Lab pH Lab SC TDS ID (mg/l) (mg/l) (mg/l) 130553 400MCRB 148194 400MCRB 0 10 <.25P 0.26 17.7 <.003 7.84 389.6 248.95 148194 400MCRB 0 10 <.25 0.25 17.7 1.1 7.83 404.37 256.31 6397 400MCRB 0 22.7 12.21 0.1 20.3 <.002 7.99 636.26 452.08 80915 400MCRB 0 <2.5 .42P <.1 18.4 <.003 7.3 375.26 237.86 83195 400MCRB MAX 0 22.7 12.21 0.26 20.3 1.1 7.99 636.26 452.08 MIN 0 10 12.21 0.1 17.7 1.1 7.3 375.26 237.86 AVERAGE 0 14.233333 12.21 0.203333333 18.525 1.1 7.74 451.3725 298.8

CHAPTER 2 - DELINEATION

The source water protection areas for the Kila School public water system are delineated in this chapter. The purpose of delineation is to map the source of drinking water for the public water supply and to define areas within which to prioritize source water protection efforts. Normally for a public water supply using groundwater there are three source water protection regions delineated for each well. They include: 1) a 100-foot control zone, 2) an inventory region based on 3-year Time-Of-Travel (TOT) estimations, a fixed radius circle, or based on hydrogeologic mapping, and 3) a recharge region corresponding to the watershed that surrounds the public water supply. For groundwater sources that are located close to streams, a surface water buffer region is also routinely delineated. The inventory region established for the school is a one-mile fixed radius circle and the focus of the inventory is directed to land areas that are up-gradient from the school’s well. Up-gradient areas are those where groundwater beneath the land is moving toward the school’s well. In this case, up-gradient areas are generally west of the school. Land areas where groundwater is moving away from the well are referred to as down-gradient from the well.

The goal of management in the control zone is to avoid introducing contaminants directly into the water supply's wells or the immediate surrounding areas. The inventory and surface water buffer regions should be managed to prevent contaminants from reaching the well before natural processes reduce their concentrations. The goal of management in the recharge region is to maintain and improve water quality over long periods of time or increased usage.

HYDROGEOLOGIC CONDITIONS

Geologic maps available for the Kila area are listed in Table 3. Available Hydrogeologic investigations for the area are listed in Table 4.

Table 3. List of geologic maps available for the Kila area.

Title or Description Date Area Covered Reference

Geologic and Structure Maps of the Kalispell USGS Miscellaneous Geologic Lat 48°, 30’ to 49° 1:250,000 1° x 2° Investigation I2267 (Harrison et al., 1992 Long 105° to 106° quadrangle, Montana, 1992) Alberta, British Columbia Geologic and Structure United States Geological Survey Maps of the Choteau 1 x Lat 47 to 49 1998 Miscellaneous Investigation 2593 2 quadrangle, northwestern Long 114 to 116 (Harrison et al., 1998) Montana Montana Bureau of Mines and Geology 1955 Geologic Map of Montana State of Montana Geologic map of Montana (Ross et al.,

1955) Surficial geologic map of Montana Bureau of Mines and the upper Flathead River Lat 48° to 48° 30’ Geology, Montana Groundwater valley (Kalispell Valley) 2002 Long 113° 52’ 30” Assessment Atlas No. 2, Part B, Map 6 area, Flathead County, to 114° Open-File Version (Smith, 2002) Montana

The Quaternary History of the Cordilleran Ice Sheet T21N-28N Masters thesis Montana State 2004 Fringe, Ashley Lake Area, R21W-24W University Montana

Middle Belt Carbonates are recorded in well logs as the primary aquifer in the vicinity of Kila School. Most of the wells in the area target this aquifer. Other wells are in the Ravalli Group aquifer. The contact between the Middle Belt Carbonates and Ravalli Group is very close to the Kila School (Appendix A, Fig. 5). Both the Middle Belt Carbonate and Ravalli Group aquifers are part of the deep bedrock aquifer. According to Smith (2000) the deep bedrock aquifer is usually found at depths greater than 100 feet. The deep aquifer includes laterally continuous sand/gravel deposits and fractured bedrock. The bedrock posesses sufficient fracture permeability to yield water to wells in the area. This includes the bedrock aquifer serving the Kila well. Its worth noting that the bedrock aquifer in this area does not have a high hydraulic conductivity as all of the wells drilled for the school demonstrate. The wells have yield relatively small volumes of water accompanied by substantial drawdown during pumping, on the order of 300 feet or more. This shows that the fracture network within the bedrock aquifer does not transmit water very efficiently.

In the foothills and surrounding Kila, glacial till confines the bedrock. The glacial till consists of silty and clayey glaciolacustrine sediments that were deposited as the glacier receded (Smith, 2000). Since these deposits are sparsely distributed in the Kila area, they are not considered a confining unit here. The depth of the deep alluvium varies depending on land-surface topography. Since topography in the Kila vicinity is mountainous, the depth to the deep alluvium is only about 100 feet (Appendix A, Fig. 6). No deep alluvium exists in the topographically higher Salish Mountains while in the depocenter of Kalispell Valley (at the Ashley Creek and Flathead River confluence), deep alluvium is at a depth of approximately 400 feet. In this case, there is no laterally extensive unit confining the aquifer. The alluvium is 100 feet deep and the well is completed in the hard fractured bedrock.

LOCAL HYDROGEOLOGIC SETTING

Driller’s logs with lithology information were retrieved from the MBMG Groundwater Information Center (GWIC) for the 10 wells with complete water quality data (Tables 1 and 2) in the deep bedrock aquifers. All wells contain layers consisting of a combination of clay, sand, and gravel. The logs demonstrate that bedrock is encountered routinely between 40 and 80 feet below the land surface. Often clay-dominated layers overlie the bedrock. One log indicates that the bedrock contact is sometimes present at great depth. The lithologic logs can be found in Appendix D. The occurrence of water is indicated in blue with the GWIC ID # labeled at the top of each log.

According to the lithologic logs, water is found as shallow as 50 feet and as deep as 505 feet. The predominant interval in which water is found is 200 to 350 feet deep. Again, groundwater moves through the fractures or cracks in the rock rather than through intergranular spaces as in sand and gravel deposits. Water does not appear to be present in intervals composed of solely clay or a combination of clay and gravel. This is as expected based on the geology of the region and the way clay fills pore space in gravel deposits. Water can be found in an interval with clay, sand, and water, but this is rare. Water is also found solely in gravel intervals, but a rare case for the area. In this situation, fractured bedrock provides most of the water in the Kila region.

None of the lithologic logs indicate water at a depth of less than 50 feet deep. This does not mean that water doesn't exist in this interval or that it can not seep through this interval. Indeed, Ashley Creek flows through the area and may lose water to the aquifer below. According to the potentiometric map (Appendix A, Fig. 12), topographic relief has a strong effect on determining the direction that groundwater moves. The potentiometric surface generally follows the topography as groundwater flows from the mountains toward the Smith Valley then northeast to the Flathead Valley. Groundwater flow follows Ashley Creek and its tributaries from southwest to northeast (Appendix A, Fig. 12). Water is probably found in some Pleistocene glacial deposits proximal to the river most likely occurring under unconfined conditions (Smith, 2001). It is likely that vertical groundwater flow components likely exist although the potentiometric map mostly shows a horizontal flow.

The following maps are available in Appendix A for reference: General Kila area geology, Figure 5; Altitude and depth to bedrock in the Kila area, Figure 6 ; Example of Fracture Bedrock, Figure 7; Potentiometric Surface map, Figure 12; Dissolved constituents in the Kila area, Figure 13.

CONCEPTUAL MODEL AND ASSUMPTIONS

Deep fractured bedrock is the source of water for the school’s well. Based on data from the potentiometric map of the area, groundwater flow is generally to the northeast (Figures 12 and 13 from LaFave, 2000). There is also likely a connection between surface and groundwater in the recharge region although the nature of the connection is unknown. Snowmelt during spring runoff is a major component of recharge. The Salish Mountains serve as the major recharge area for the aquifer. An absence of fine-grained material in the well logs and exposure of the Ravalli Group at the surface implies there is no confining unit or a discontinuous confining unit. Based on the logs, the aquifer serving Kila School is interpreted to be locally confined. A deep confined aquifer is considered to have a low sensitivity to potential contaminant sources located at or near the land surface. The Quaternary alluvium may serve as a conduit for vertical surface water interactions with the ground water.

Table 4. List of hydrogeologic investigations for the Kila area.

Period of Title of Project Area Covered Project Purpose Project T26N – T31N Potentiometric Surface Montana Ground-Water R18W - R23W, Map of the Deep Aquifer, Assessment Atlas No.2, 2000 Kalispell Valley, Flathead Part B, Map 2, Open-File 47° 4’-48° 30’ County, Montana (LaFave, 2000) 114°-114° 30’ Quaternary Geology, Rocky Mountain Section Geomorphology, and of the Geological Society Upper Flathead Hydrogeology of the upper 2000 of America, University of County, Montana Flathead River Valley area, Montana (Smith et al., Flathead County, Montana 2000) Altitude of and Depth to Montana Ground-Water the Bedrock Surface: T15N-32N, Assessment Atlas No.2, Flathead Lake Area, 2000 R19W-24W Part B, Map 7 (Smith, Flathead and Lake 2000a) Counties, Montana T25-32N, Montana Ground-Water Dissolved Constituents R18W - 23W Assessment Atlas No.2, Map of the Deep Aquifer, 2001 Part B, Map 3, Open-File Kalispell Valley: Flathead 47° 4’-48° 30’, Version December County, Montana 114° -114° 30’ (Smith, 2001) Montana Ground-Water Ground-Water Resources Assessment Atlas No.2, of the Flathead Lake Area: T15N-32N, Part A – Descriptive Flathead, Lake, Sanders 2004 R12W-27W Overview and Water- and Missoula Counties, Quality Data (LaFave et Montana al., 2004) T26N-32N, Depth to Deep Alluvium of R18W-23W Montana Ground-Water the Deep Aquifer in the Assessment Atlas No.2, 2000 Kalispell Valley, Flathead 48°-48° 30’ Part B, Map 9 (Smith, County, Montana 113° 52’30” 2000c) 114° 37’ 30” T26N-32N Thickness of the Confining Montana Ground-Water R18W-23W Unit in the Kalispell Assessment Atlas No.2, 2000 48°-48° 30’ Valley, Flathead County, Part B, Map 8 (Smith, 113° 52’ 30”- Montana 2000c) 114° 37’ 30”

WELL INFORMATION

The well from which the Kila School obtains water (GWIC ID139464 ) is on Kila Road approximately 670 feet north of the Kila Hill Road/Kila Road intersection. The well was completed on September 21, 1993 according to the well log. The well was drilled to a

depth of 440 feet and is reported to be completed in the Middle Belt Carbonate (400MCRB) aquifer (GWIC, 2005), but may be in the Ravalli Group as described below. Six inch diameter steel casing was emplaced to a depth of 115 feet. Four inch PVC casing continues to a depth of 400 feet. The annular seal is bentonite which should prevent access of shallow water and contamination to the well. The depth of this seal is from 0-20 feet (Appendix C). The location of the Kila School well is shown in Appendix A, Figures 1, 2, 3 and 4.

LIMITING FACTORS

No hydrogeologic investigations with specific values for hydrogeologic variables for the school have been completed in the area. However, one study by LaFave, (2000) with potentiometric information was available and was helpful for interpreting flow direction and recharge zone. The relationship between Quaternary shallow alluvium including glacial drift deposits, and glacial outwash deposits can be complicated and is unknown in the area surrounding Kila. This complicated relationship makes it difficult to determine the exact ground-water flow characteristics and surface-water connection at this time. If thorough studies of these entities takes place in the future, this part of the report should be revisited. However, the available information is considered sufficient to complete this Source Water assessment for the school.

Table 5. Source well information for Kila School

Information Well #1 Well #2 Well #3 Sources of Information

PWS Source Code 00892 00892 0892004 Environmental Health Services, 2000 MBMG # 81140 139465 139464 GWIC Water Right # N/A N/A CO89117-00 GWIC Legal Location 27N 22W 08 AB 27N 22W 08 27N 22W 08 GWIC AB ABAA Latitude/Longitude 48.1193, - 48.1193, - 46.1214, - GWIC 114.4573 114.4573 114.4561 New Latitude/Longitude N/A N/A N/A Montana DEQ, May 2004 Date Completed 3/6/1981 9/21/1993 9/21/1993 GWIC Well Depth 690’ 500’ 440’ GWIC Perforated Interval 260-300’ N/A 420-440’ GWIC Static Water Level Depth 100’ 100’ 103’ GWIC Pumping Water Level Depth 300’ 500’ 415’ GWIC Drawdown GWIC Test Pumping Rate 10gpm 2 gpm 16 gpm GWIC Specific Capacity GWIC Source Type Ravalli Group Ravalli Ravalli Group GWIC Group Status Abandoned well Abandoned Active GWIC cap dry hole

CHAPTER 3 - INVENTORY

Montana Source Water Protection Program (DEQ, 1999) requires that land uses and all potential contaminant sources be identified within the control zone and inventory region of non-transient non-community public water supplies. Inventory of potential sources of contamination was conducted for the Kila School within the control and inventory regions. The significant potential contaminants in the Kila School inventory region are nitrate, pathogens, fuels, solvents, and agricultural chemicals.

The inventory for Kila School focuses on all activities in the control zone, certain sites or land use activities in the inventory region, and general land uses and large facilities in the recharge region.

INVENTORY METHOD

Available databases were initially searched to identify businesses and land uses that are potential sources of regulated contaminants in the inventory region. Most of the inventory work on the internet was accomplished in winter of 2004 although final writing of the report was not completed until 2005. The following steps were followed:

Step 1: Urban and agricultural land uses were identified from the U.S. Geological Survey's Geographic Information Retrieval and Analysis System (http://nris.state.mt.us/gis/datalist.html). Sewered and unsewered residential land use were identified from boundaries of sewer coverage obtained from municipal wastewater utilities. Step 2: EPA’s Envirofacts System (http://www.epa.gov/enviro/) was queried to identify EPA regulated facilities located in the Inventory Region. This system accesses facilities listed in the following databases: Resource Conservation and Recovery Information System (RCRIS), Biennial Reporting System (BRS), Toxic Release Inventory (TRI), and Comprehensive Environmental Response Compensation and Liability Information System (CERCLIS). The available reports were browsed for facility information including the Handler/Facility Classification to be used in assessing whether a facility should be classified as a significant potential contaminant source. Step 3: The Permit Compliance System (PCS) was queried using Envirofacts (http://www.epa.gov/enviro/) to identify Concentrated Animal Feeding Operations with MPDES permits. The water system operator or other local official familiar with the area included in the inventory region identified animal feeding operations that are not required to obtain a permit. Step 4: Databases were queried to identify the following in the inventory region: Underground Storage Tanks (UST) (http://webdev.deq.state.mt.us/UST/), hazardous waste contaminated sites (DEQ hazardous waste site cleanup bureau), landfills (http://nris.state.mt.us/gis/datalist.html), abandoned mines (http://nris.state.mt.us/gis/datalist.html) and active mines including gravel pits. Any information on past releases and present compliance status was noted.

Step 5: A business phone directory was queried to identify businesses that generate, use, or store chemicals in the inventory region. Equipment manufacturing and/or repair facilities, printing or photographic shops, dry cleaners, farm chemical suppliers, and wholesale fuel suppliers were targeted by SIC code (infoUSA, 2002). Step 6: Major road and rail transportation routes were identified throughout the inventory region (http://nris.state.mt.us/gis/datalist.html). Step 7. All land uses and facilities that generate, store, or use large quantities of hazardous materials were identified within the recharge region and identified on the base map. Step 8: All wells located within the inventory region were identified and well logs were obtained when available.

INVENTORY RESULTS/CONTROL ZONE

The Kila School owns most of the land within the 100-foot control zone. This was determined by viewing the ortho photo of the vicinity (Appendix A, Fig. 3). Small roads are recognized as potential sources of contaminants. One of the concerns with the roads is pest and weed control spraying. Spraying should be kept outside of the 100 foot control zone. The school’s septic drainfield system is located just outside of the control zone and is interpreted to be in a cross-gradient location. This means that groundwater beneath the drainfield is moving parallel to the schools well and not toward it. The drainfield is located in the playground area west of the gymnasium. Due to the close proximity of the drainfield to the control zone, its hazard rating is high. If the septic system is replaced in the future, moving it further outside of the control zone and as far as possible east of the well site would help to lower the well’s susceptibility to the septic system. It is also advisable for the school to limit the washing of fertilizer, pesticide, and herbicide application and equipment near the well or near drains connected to the septic system.

INENTORY RESULTS/INVENTORY REGION

Land use information for the Kila School inventory region (Appendix A, Fig. 9) is summarized from the National Landcover Dataset, Montana (USGS, 2000). Inventory Land Cover in the Kila area is shown in Appendix A, Figure 8. In addition, a pie chart showing land use breakdown for this detailed data is included (Appendix A, Fig. 10). Land use within the 1-mile inventory zone of Kila School includes 37.26% grassland/herbaceous, 15.07% evergreen forest, 13.82% woody wetlands, 11.72% pasture/hay, 7.66% mixed forest, 5.23% emergent/herbaceous, 3.25% bare rock, 2.13% high intensity residential, 2.11% water and less than 1% perennial ice/snow and low intensity residential. This results in less than 12% agricultural land in the inventory region.

According to the Computer Assisted Mass Appraisal (CAMA, 2004) database (derived from the Montana Department of Revenue), 29% (578 acres) of the inventory region is considered agricultural. Most of the agricultural use (84.3%, 487 acres) is for commercial timber. Approximately 8.8% (51 acres) is under one ownership (2-160 acres) for which no agricultural application has been approved. Approximately 6.9% (40 acres) is for hay

production. Since less than 20% of this area is cropped agricultural land, it is not considered a significant potential contaminant source, so is given a low hazard rating.

The septic density in the Kila School inventory region is variable throughout. The area at the school is on the border between medium and low septic-system density (Appendix A, Fig.2). Approximately 890 feet southwest and upstream of the Kila School, septic-system density is high. Medium septic-system density is bordered by Highway 2 and Kila Road for approximately 1.56 miles. The inventory region surrounding Kila School is an area of approximately 2,008 acres. Low septic density comprises 87.7% of this region (approximately 1,762 acres). Medium septic density constitutes 243 acres and 12.1% of the inventory region. High septic density comprises 3 acres of the area (0.15% of the inventory). Due to the proximity of high and medium septic densities, active and abandoned septic systems are given a moderate hazard rating.

Highway 2 is within the one mile radius Inventory Region approximately 2000 feet west of the well (Appendix A, Fig. 3). It is the main road accessing the Flathead Valley. Although this highway is a main road for this area, the traffic volume is relatively low, especially for large vehicles transporting potentially hazardous materials. The highway is given a low hazard rating for potential contaminants.

There are 2 underground storage tank (UST) sites listed with the Department of Environmental Quality. None of these tanks are active within the one-mile inventory region. The former Highway Trading once had two underground gasoline storage tanks. Both have been removed from the ground and are permanently out of use. The Kila School was the previous site of one underground heating oil storage tank. The tank was removed and is permanently out of use. The two underground storage tanks are present in the UST shapefile available from the Montana Natural Resources and Information System database (Montana NRIS).

An additional two active, leaking underground storage tanks (LUST) are listed with the Montana DEQ (Montana, DEQ, UST/LUST data) at the Former Highway Trading site. The tank sites appear to be a minimum of ¼ mile from the schools well. One of the tank sites is located to the northeast and this location is down-gradient from the well. Down-gradient means that groundwater beneath the tank site is moving away from the school’s well and not toward it. Due to the location and distance from the school’s well, the hazard associated with the USTs/LUSTs is considered low.

Table 6. Underground storage tanks in the recharge region listed with the Montana DEQ. Facility Street Active AltFacilityID City Notes NonactiveTanks Name Address Tanks Ashley Creek 15-04617 6230 Hwy 2 W Kila 0 1 Ranch Tank removed 15-06982 Kila School 325 Kila Road Kila 0 1 from ground 12/6/1993 Tanks Highway removed 15-09826 4375 Hwy 2 W Kila 0 2 Trading from ground 12/20/1998 22

Table 7. Leaking underground Storage Tanks listed with Montana Department of Environmental Quality. Confirmed Site # of AltEvent Contact City Location Date Release Active Name Tanks ID Person Date Martha Highway 19- Hodges, 4375 US-2 1509826*31 Kila Trading 2 May- 1-Jun-1997 clerk Yes W 82 Former 1986 (406) 257- 2428

INVENTORY RESULTS/RECHARGE REGION

Land use within the Kila School recharge region (Appendix A, Figures 9 and 11) includes 75.14% evergreen forest, 7.13% shrubland, 4.74% grassland/herbaceous, 4.17% transitional, 3.71% water, 3.39% pasture/hay, and less than 1% perennial ice and snow, low intensity residential, commercial/industrial, bare rock, deciduous forest, fallow, woody wetlands and emergent/herbaceous. This results in a total of 3.39% agricultural land in the recharge region.

The highway through the inventory region continues west and southwest but there are no additional possible contaminant sources within the recharge region.

INVENTORY UPDATE

The certified operator is encouraged to maintain and update the inventory for the school on an annual basis. Updates can also be provided to the DEQ every 5 years which will help ensure that this Source Water Delineation and Assessment Report is up-to-date and accurate.

INVENTORY LIMITATIONS

The potential sources of contamination for the Kila School have been identified using readily available data and reports. Unregulated activities or unreported contaminant releases may have been missed. The use of multiple sources of data, however, should ensure that the major potential contaminant threats to the Kila School are known. On-site visits were not performed, so locations of some important data may be incorrect.

CHAPTER 4 - SUSCEPTIBILITY ASSESSMENT

Susceptibility is the potential for a public water supply to draw water contaminated by inventoried sources at concentrations that would pose concern. Susceptibility is assessed in order to prioritize potential pollutant sources for management actions by local entities, including the Kila School.

The goal of Source Water Management is to protect the source water by 1) controlling activities in the control zone, 2) managing significant potential contaminant sources in the Inventory Region, and 3) ensuring that land use activities in the Recharge Region pose minimal threat to the source water. Management priorities in the Inventory Region are determined by ranking the significant potential contaminant sources identified in the previous chapter according to susceptibility. Alternative management approaches that could be pursued by the Kila School to reduce susceptibility are recommended.

Susceptibility is determined by considering the hazard rating for each potential contaminant source and the existence of barriers that decrease the likelihood that contaminated water will flow to the school’s well. Hazard for confined aquifers is low if all wells in the inventory region, including the PWS well, are properly sealed. Hazard is moderate if the PWS well is sealed but other wells within the inventory region are not properly sealed. Hazard is high if all wells, including the PWS well, are not properly sealed. For this report, the school’s active well is considered to be properly sealed with the bentonite seal extending into clay-dominated layers above the fractured bedrock aquifer. Because not all of the other wells within the inventory region are properly sealed, the hazard rating for most of the potential contaminant source that are point sources is set to moderate. Several barriers are identified for the school’s well. Well depth and, in some cases, down-gradient location, are counted as barriers. Hazard and susceptibility ratings are presented in Table 9. Table 9 also includes management options that can be pursued either by the school or by county officials to help protect the school’s source water.

Hazard is ranked moderate for UST/LUSTs as potential contaminant sources because the tanks have been removed within the last fifteen years. The active tanks are approximately 1700 feet from the school’s well. Susceptibility is ranked low with well depth and distance from the well counted as barriers.

Hazard is ranked moderate for Highway 2 as a potential contaminant source since applied or spilled chemicals can migrate to the unconfined aquifer. Susceptibility is ranked low counting depth of the well and low traffic volume as barriers.

Hazard is ranked high for other school wells. The sanitary survey states that one of the unused wells has been filled with cement and the other unused well is capped. The concern is that the unused wells could provide a direct conduit for surface contamination into groundwater. Susceptibility is ranked moderate counting the aquifer’s low hydraulic conductivity, the steps taken to abandon one well, and the capping of the other as barriers. Nevertheless, proper abandonment of the capped well and best management practices (BMPs) such as having positive drainage away from the well and ensuring hazardous

24 materials are not stored or used around the well is encouraged. Pest control spraying should also be prohibited in the vicinity of the unused wells.

Hazard is ranked high for the school septic system which is a large capacity system serving more than 20 persons per day and it is located within the 100 foot control zone. The drainfield is between 100 and 500 feet of the well. Depth to the well is the only barrier, so susceptibility is high. If the septic system is replaced in the future, it is strongly advised to locate the replacement system outside of the 100 foot control zone, the farther the better, and in a location east of the school’s well.

Based on the small number of possible contaminant sources and the general lack of barriers to flow, the overall susceptibility of the Kila School well to potential contaminant sources is considered moderate. Table 9 summarizes the inventory results and the susceptibility analysis. The table also includes some management options that could be pursued by the school and county officials.

Table 8a. Relative susceptibility to specific contaminant sources as determined by hazard and the presence of barriers. Presence Of Hazard Barriers High Moderate Low No Barriers Very High Moderate High Susceptibility Susceptibility Susceptibility One Barrier High Moderate Low Susceptibility Susceptibility Susceptibility Multiple Moderate Low Very Low Barriers Susceptibility Susceptibility Susceptibility

Table 8b. Hazard of potential contaminant sources for unconfined aquifers. Potential The PWS well is not Other wells in the All wells in the Contaminate sealed through the inventory region are inventory region Sources confining layer not sealed through are sealed through the confining layer the confining layer Point Sources High Moderate Low

Septic Systems High: > 300 Moderate: > 300 Low (# per square mile) Moderate: 50 to 300 Low: < 300 Low: < 50 Sanitary Sewer High: > 50 Moderate: > 50 Low (% land use) Moderate: 20 to 50 Low: < 50 Low: < 20 Cropland High: > 50 Moderate: > 50 Low (% land use) Moderate: 20 to 50 Low: < 50 Low: < 20

Table 9. Susceptibility assessment for significant potential contaminant sources in the inventory region. Potential Potential Hazard Management Contaminant Hazard Barriers Susceptibility Contaminants Rating Recommendation Source Properly operate and maintain the onsite septic system and -Well Depth distribution lines. A two to three School septic Ongoing or catastrophic Nitrates, -Low Aquifer year septic tank pumping system and leakage of sewage into High Moderate pathogens Hydraulic maintenance schedule is service line groundwater Conductivity recommended. Consider connecting to municipal sewer system, if available Encourage proper abandonment or -Well Depth renovation of inactive, failing or Improperly installed or Pesticides, -One is unused wells. Encourage use of maintained wells may Other school fertilizers, cement filled best management practices provide a direct conduit High Moderate wells VOCs, SOCs, -Low Aquifer (BMPs) such as having positive for surface contamination other Hydraulic drainage away from the well and into groundwater Conductivity ensuring hazardous materials are not stored or used around the well. Contact DEQ’s Waste and -Well Depth Underground Tank Management -Distance Bureau (406-444-5300) to review VOCs, SOCs, Contaminants leaching to from well UST/LUSTs Moderate Low status and any permits or inorganics groundwater -One is monitoring network to verify down- existing contamination is being gradient properly removed or remediated Abandoned Ongoing or catastrophic See school septic Nitrates and and active leakage of sewage into Moderate -Well Depth Moderate recommendations above pathogens septic systems groundwater

Notify landowners of well and protection area locations. Encourage and support emergency Pesticides, Spills, routine spraying, planning, training of local -Well Depth fertilizers, storm water runoff, emergency response personnel, Highway 2 Moderate -Low traffic Low VOCs, SOCs, infiltration into use of levees and engineered volume other groundwater storm drainage to carry any spills away and prevent infiltration into ground, cooperation with railroad managers or MDOT to reduce herbicide use. Notify landowners of well and protection area locations. Encourage and support efforts to provide educational information, Cropped Nitrates, Nitrates, pathogens & -Well Depth materials, and resources to land Agricultural pathogens, agchemicals leaching to Low -Distance Low owners on the proper application Land agchemicals groundwater from well and storage of pesticides and fertilizers and implementing agricultural best management practices (BMPs). Notify landowners of well and protection area locations. Encourage and support emergency -Well Depth planning, training of local Other small Contaminants leaching to All Low -Low traffic Low emergency response personnel, roads groundwater volume use of levees and engineered storm drainage to carry any spills away and prevent infiltration into ground, cooperation with MDOT to reduce herbicide use.

REFERENCES

CAMA, 2004, http://nris.state.mt.us/nsdi/cadastral/.

Census Bureau, 2003, http://ceic.commerce.state.mt.us/C2000/PL2000/places90-2000.htm, http://ceic.commerce.state.mt.us/C2000/PL2000/places90-2000.htm, census information MT population http://ceic.commerce.state.mt.us/, census info MT economic and other information.

DEQ, 1999, Department of Environmental Quality http://www.deq.state.mt.us/index.asp

GWIC Groundwater Information Center, 2005, http://mbmggwic.mtech.edu/

Environmental Health Services, 2000, Sanitary Survey Inspection Kila School PWS #892.

Harrison, J.E., Cressman E.R., Whipple, J.W., 1992, Geologic and Structure Maps of the Kalispell 1° x 2° Quadrangle, Montana, and Alberta and British Columbia, USGS Miscellaneous Investigations Series Map I-2267, scale 1:250,000.

Harrison, J.E., Griggs, A.B., Wells, J.D., 1986, Geologic and structure maps of the Wallace 1° X 2° quadrangle, Montana and Idaho, United States Geological Survey Miscellaneous Geologic Investigation 1509-A, scale 1:250000.

Heath, R.C., 1984, Introduction to State summaries of ground-water resources, U. S. Geological Survey Water-Supply Paper, p. 118-121.

Howard, A.D. and Williams, J.W., 1972, Physiography, in Mallory, W.W. (ed. in chief), Geological Atlas of the Rocky Mountain Region: Rocky Mountain Association of Geologists, Denver, CO, p. 29-31.

LaFave, J.I., 2000, Potentiometric Surface Map of the Southern Part of the Flathead Lake Area, Lake, Missoula, Sanders, Counties, Montana, Montana Groundwater Assessment Atlas 2, Part B, Map 4, Open-File Version, December 2000, Montana Bureau of Mines and Geology at Montana Tech of the University of Montana.

Malkuch, T., 2005, operator of the Kila School District #20 Public Water Supply, personal communication.

Mapquest, 2004, http://www.mapquest.com/.

Montana DEQ, 2001, BacT database.

Montana DEQ, 1999, Montana Source Water Protection Program, Approved by EPA in November 1999.

Montana DEQ Public Water Supply Program, 2005, http://www.deq.state.mt.us/wqinfo/pws/index.asp.

Montana DEQ Source Water Protection Program’s Mapper GIS application, 2005, http://nris.state.mt.us/mapper/.

Montana DEQ, UST/LUST Data, 2005, http://www.deq.state.mt.us/rem/tsb/iss/USTDownloads.asp.

Mudge, M.R., Earhart, R.L., Whipple, J.W., Harrison, J.E., 1983, Geologic and Structure Maps of the Choteau 1°x 2° quadrangle, Northwestern Montana, Montana Bureau of Mines and Geology in cooperation with the United States Geological Survey, Montana Atlas Series 3-A.

NRCS National Water and Climate Center, 2005, http://www.wrcc.dri.edu/summary/climsmmt.html

NRIS Natural Resource Information System, 2004 http://nris.state.mt.us/

Patton, T.W., Smith, L.N., and LaFave, J.I., 2003, Ground-Water Resources of the Flathead Lake Area: Flathead, Lake, Sanders and Missoula Counties, Montana, Montana Bureau of Mines and Geology Information Pamphlet No. 4, January 2003.

Ross, Clyde P., Andrew, David A., Witkind, Irving, 1955, Geologic Map of Montana, Montana Bureau of Mines and Geology.

Smith, L.N., 2000, Thickness of Shallow Alluvium, Flathead Lake Area, Flathead, Lake, Missoula, and Sanders Counties, Montana, Montana Ground-Water Assessment Atlas No. 2, Part B, Map 11 Open-File Version December 2000, Montana Bureau of Mines and Geology at Montana Tech of the University of Montana.

Smith, L.N., 2001, Hydrogeologic Framework of the Southern Part of the Flathead Lake area, Flathead, Lake, Missoula, and Sanders Counties, Montana, Montana Ground- Water Assessment Atlas No. 2, Part B, Map 10, Open-File Version February 2001.

Smith, L.N., 2002, Surficial Geologic Map of the upper Flathead River valley (Kalispell valley) Area, Flathead County, Northwestern Montana, Montana Ground-Water Assessment Atlas No. 2, Part B, Map 6, Open-File Version, January 2002, Montana Bureau of Mines and Geology at Montana Tech of the University of Montana.

U.S. Department of Agriculture, Soil Survey of the Lake County Area, Montana, Report MT629, Natural Resource Conservation Service, on Montana Natural Resource Information System, , July 1996,. http://www.nris.state.mt.us/nrcs/soils/datapage.html

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U.S. Environmental Protection Agency, Office of Water, 1991, Manual of Small Public Water Supply Systems, EPA 570/9-91-003, p. 211

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APPENDICES

APPENDIX A FIGURES

APPENDIX B SITE PLAN

APPENDIX C WELL LOG(s)

APPENDIX D LITHOLOGIC LOGS FROM OTHER WELLS IN THE VICINITY

APPENDIX E

DEQ WATER QUALITY DATA

APPENDIX F

SANITARY SURVEY APPENDIX G

HAZARD AND BARRIER WORK SHEETS

APPENDIX A - FIGURES

Figure 1. Kila vicinity map. Blue square indicates Kila public water supply (PWS) Figure 2. Private and public water supply wells and potential contaminant sources in the general location of Kila

Figure 3. Digital orthophotos of Kila Inventory (upper photo) and Control (lower photo) Zones. Arrows indicate direction of groundwater flow.

Figure 4. Kila Recharge Region. Arrows indicate direction of groundwater flow.

Figure 5. Montana Geologic Map and Kila Vicinity Geology (U.S. Geological Survey, 1998). Kila PWS=

Figure 6. Altitude of and Depth to the Bedrock Surface, Kila area (Smith, 2000) Water well location ----3000---- Contour (feet) Outcrop area of pre-Tertiary rocks, predominantly Proterozoic Belt Supergroup Quaternary and some Tertiary units Water bodies Kila PWS

Figure 7. Example of bedrock fracturing in the Belt Supergroup common for the Kila area. Belt rocks underlie the Salish Mountains at Kila. F1 and F2 are two sets of fractures in this roadcut. DH are drillholes used to expose the roadcut that are analogous to water wells that intersect subsurface fractures. Location: T 27 N, R 21 W, sec 6 (Patton et al., 2003).

Figure 8. Kila Land Use Inventory Zone

Figure 9. Kila Land Use Recharge Region

Figure 10. Land Use percentages for Kila’s Inventory Zone

Emergent/herbace Water Pasture/hay ous Water Grassland/herbac 3% 1% 4% Perennial ice and snow eous Low intensity residential 5% Transitional Commercial/industrial 4% Bare rock Shrubland 7% Transitional Deciduous forest Evergreen forest Shrubland Grassland/herbaceous Pasture/hay Evergreen forest Fallow 76% Woody wetlands Emergent/herbaceous

low intensity high intensity residential residential deciduous water water forest emergent/herba perennial ice/snow ceous bare rock low intensity residential woody wetlands high intensity residential evergreen forest bare rock deciduous forest pasture/hay mixed forest evergreen forest mixed forest grassland/herbaceous pasture/hay grassland/herba woody wetlands ceous emergent/herbaceous

Figure 11. Land Use percentages for Kila’s Recharge Region

Figure 12. Potentiometric surface map of the Kila area and part of Flathead Valley (LaFave, 2000). Kila PWS

Figure 13. Dissolved constituents in the Kila area (LaFave, 2000). Kila PWS

APPENDIX B - Site Plan

APPENDIX C - Well Log and Well Log Report

Montana Bureau of Mines and Geology Ground-Water Information Center Site Report KILA SCHOOL DISTRICT #20 - WELL 3 Location Information GWIC Id: 139464 Source of Data: LOG Location (TRS): 27N 22W 08 ABAA Latitude (dd): 48.1214 County (MT): FLATHEAD Longitude (dd): -114.4561 DNRC Water Right: C089117-00 Geomethod: MAP PWS Id: 00892004 Datum: NAD27 Block: Altitude (feet): Certificate of Lot: Survey: Addition: Type of Site: WELL Well Construction and Performance Data Total Depth (ft): 440.00 How Drilled: ROTARY Static Water Level (ft): 103.00 Driller's Name: BILLMAYER Pumping Water Level 415.00 Driller License: WWC335 (ft): Yield (gpm): 16.00 Completion Date (m/d/y): 9/21/1993 Test Type: PUMP Special Conditions: Test Duration: 7.00 Is Well Flowing?: Drill Stem Setting (ft): Shut-In Pressure: Recovery Water Level Geology/Aquifer: 400MCRB (ft): Recovery Time (hrs): Well/Water Use: PUBLIC WATER SUPPLY Well Notes: Hole Diameter Information Casing Information1 From To Diameter Wall Pressure 0.0 20.0 10.0 From To Dia Thickness Rating Joint Type 20.0 117.0 8.0 -2.0 115.0 6.0 STEEL 100.0 400.0 4.0 PVC

117.0 440.0 6.0

Annular Seal Information Completion Information1 From To Description # of Size of 0.0 20.0 BENTONITE From To Dia Openings Openings Description FACTORY 420.0 440.0 4.0 SLOTTED

Lithology Information

From To Description 0.0 109.0 CLAY AND BOULDERS 109.0 175.0 GREEN ROCK 175.0 192.0 GREEN ROCK AND WATER 192.0 300.0 GREEN ROCK 300.0 340.0 GREEN ROCK WITH FRACTURES 340.0 390.0 GREEN ROCK 390.0 425.0 FRACTURED DARK GREEN ROCK 425.0 430.0 FRACTURED GREEN ROCK & WATER 430.0 440.0 HARD GREEN ROCK

Montana Bureau of Mines and Geology Plot this site on a topographic map Ground-Water Information Center Site Report KILA SCHOOL Location Information GWIC Id: 81140 Source of Data: LOG Location (TRS): 27N 22W 08 AB Latitude (dd): 48.1193 County (MT): FLATHEAD Longitude (dd): -114.4573 DNRC Water Right: Geomethod: TRS-SEC PWS Id: Datum: NAD27 Block: Altitude (feet): Certificate of Lot: Survey: Addition: Type of Site: WELL Well Construction and Performance Data Total Depth (ft): 690.00 How Drilled: FORWARD ROTARY Static Water Level (ft): 100.00 Driller's Name: BILLMAYER Pumping Water Level 300.00 Driller License: WWC335 (ft): Yield (gpm): 10.00 Completion Date (m/d/y): 3/6/1981 Test Type: AIR Special Conditions: Test Duration: 4.00 Is Well Flowing?: Drill Stem Setting (ft): Shut-In Pressure: Recovery Water Level Geology/Aquifer: 400MCRB (ft): Recovery Time (hrs): Well/Water Use: UNKNOWN Well Notes: Hole Diameter Information Casing Information1 No Hole Diameter Records currently in GWIC. Wall Pressure From To Dia Thickness Rating Joint Type 0.0 229.0 6.0 STEEL

Annular Seal Information Completion Information1 From To Description # of Size of 0.0 20.0 CEMENT From To Dia Openings Openings Description 260.0 300.0 0.0 1/4X6 SLOTS

Lithology Information From To Description 0.0 1.0 TOPSOIL 1.0 15.0 BROWN CLAY AND BOULDERS 15.0 60.0 BROWN CLAY AND GRAVEL 60.0 260.0 GREEN ROCK AND FRACTURE

260.0 300.0 GREEN ROCK AND WATER 300.0 400.0 GREEN ROCK 400.0 600.0 FRACTURED GREEN ROCK 600.0 660.0 GREEN ROCK 660.0 670.0 FRACTURED ROCK AND WATER 670.0 690.0 GREEN ROCK

Montana Bureau of Mines and Geology Plot this site on a topographic map Ground-Water Information Center Site Report KILA SCHOOL DIST 20 Location Information GWIC Id: 144874 Source of Data: Location (TRS): 27N 22W 08 AB Latitude (dd): 48.1193 County (MT): FLATHEAD Longitude (dd): -114.4573 DNRC Water Right: Geomethod: TRS-SEC PWS Id: Datum: NAD27 Block: Altitude (feet): Certificate of Lot: Survey: Addition: Type of Site: WELL Well Construction and Performance Data Total Depth (ft): 440.00 How Drilled: Static Water Level (ft): Driller's Name: Pumping Water Level Driller License: (ft): Yield (gpm): Completion Date (m/d/y): Test Type: Special Conditions: Test Duration: Is Well Flowing?: Drill Stem Setting (ft): Shut-In Pressure: Recovery Water Level Geology/Aquifer: 400MCRB (ft): Recovery Time (hrs): Well/Water Use: Not Reported Well Notes: Hole Diameter Information Casing Information1 No Hole Diameter Records currently in GWIC. No Casing Records currently in GWIC. Annular Seal Information Completion Information1 No Seal Records currently in GWIC. No Completion Records currently in GWIC. Lithology Information No Lithology Records currently in GWIC.

Montana Bureau of Mines and Geology Plot this site on a topographic map Ground-Water Information Center Site Report KILA SCHOOL Location Information GWIC Id: 139465 Source of Data: LOG Location (TRS): 27N 22W 08 AB Latitude (dd): 48.1193 County (MT): FLATHEAD Longitude (dd): -114.4573 DNRC Water Right: Geomethod: TRS-SEC PWS Id: Datum: NAD27 Block: Altitude (feet): Certificate of Lot: Survey: Addition: Type of Site: WELL Well Construction and Performance Data Total Depth (ft): 500.00 How Drilled: ROTARY Static Water Level (ft): 100.00 Driller's Name: BILLMAYER Pumping Water Level 500.00 Driller License: WWC335 (ft): Yield (gpm): 1.50 Completion Date (m/d/y): 9/21/1993 Test Type: AIR Special Conditions: Test Duration: 2.00 Is Well Flowing?: Drill Stem Setting (ft): Shut-In Pressure: Recovery Water Level Geology/Aquifer: 400MCRB (ft): Recovery Time (hrs): Well/Water Use: PUBLIC WATER SUPPLY Well Notes: Hole Diameter Information Casing Information1 No Hole Diameter Records currently in GWIC. Wall Pressure From To Dia Thickness Rating Joint Type -2.0 91.0 6.0 STEEL

Annular Seal Information Completion Information1 From To Description No Completion Records currently in GWIC. 0.0 20.0 BENTONITE

Lithology Information From To Description 0.0 1.0 TOPSOIL 1.0 62.0 CLAY AND BOULDERS 62.0 140.0 FRACTURED GREEN ROCK 140.0 475.0 LIGHT & DARK GREEN ROCK

475.0 500.0 FRACTURED GREEN ROCK

APPENDIX E – DEQ Water Quality Monitoring Data Available Upon Request

APPENDIX F - Sanitary Surveys Available Upon Request

APPENDIX G - Hazard and Barrier Worksheets Available Upon Request