City of Cut Public Water Supply PWSID # MT0000193

Date of Report: March 20, 2003

SOURCE WATER DELINEATION AND ASSESSMENT REPORT

Operator/Manager:

Keith Nelson 113 East Main Street Cut Bank, MT 59427 (406) 873-2362 City of Cut Bank SWDAR Table of Contents

INTRODUCTION ...... 1 PURPOSE...... 1 LIMITATIONS...... 1 BACKGROUND...... 2 THE COMMUNITY...... 2 CLIMATE...... 2 GEOGRAPHIC SETTING ...... 3 ...... 3 THE PUBLIC WATER SUPPLY...... 4 CUT BANK PWS WATER QUALITY ...... 5 DELINEATION...... 6 HYDROGEOLOGIC CONDITIONS...... 6 CONCEPTUAL MODEL AND ASSUMPTIONS...... 7 DELINEATION RESULTS ...... 8 Spill Response Region ...... 8 Watershed Region ...... 8 LIMITING FACTORS ...... 8 INVENTORY...... 9 INVENTORY METHOD ...... 9 INVENTORY RESULTS/SPILL RESPONSE REGION ...... 10 INVENTORY RESULTS/WATERSHED REGION ...... 12 INVENTORY UPDATE...... 15 INVENTORY LIMITATIONS...... 15 SUSCEPTIBILITY ASSESSMENT...... 16 SUSCEPTIBILITY ASSESSMENT RESULTS ...... 18 MANAGEMENT RECOMMENDATIONS ...... 23 MONITORING WAIVERS...... 26 WAIVER RECOMMENDATION ...... 26 MONITORING WAIVER REQUIREMENTS ...... 27 Use Waivers ...... 27 Susceptibility Waivers ...... 27 Susceptibility Waiver for Confined ...... 28 Susceptibility Waiver for Unconfined Aquifers ...... 28 REFERENCES ...... 30 GLOSSARY* ...... 31 FIGURES ...... 33 FIGURE 1: GENERAL LOCATION MAP...... 34 FIGURE 2: CLIMATE SUMMARY GRAPH – IMBEDDED IN TEXT ON PAGE 3...... 35 FIGURE 3: SPILL RESPONSE REGION MAP WITH OTHER PUBLIC WATER SUPPLIES IN THE AREA...... 36 FIGURE 4: GENERAL GEOLOGIC MAP...... 37 FIGURE 5: DAILY FLOW FOR CUT BANK CREEK AT CUT BANK – IMBEDDED IN TEXT ON PAGE 6...... 38 FIGURE 6: PEAK FLOW LEVELS FOR THE CUT BANK CREEK AT CUT BANK – IMBEDDED IN TEXT ON PAGE 6...... 39 i

City of Cut Bank SWDAR

FIGURE 7: SPILL RESPONSE REGION AND LANDCOVER / LANDUSE MAP ...... 40 FIGURE 8: WATERSHED REGION INVENTORY MAP...... 41 FIGURE 9: CUT BANK PWS WATERSHED REGION LANDCOVER / LANDUSE MAP...... 42 APPENDICES...... 43 APPENDIX A - LISTING OF POTENTIAL CONTAMINANT SOURCES BY SIC CODE AND SUPPLEMENTAL LIST PROVIDED BY PWS OPERATOR ...... 44 APPENDIX B - DEQ PWS’S DATABASE OUTPUT ...... 47 APPENDIX C - SANITARY SURVEY...... 54 APPENDIX D - CONCURRENCE LETTER & OTHER CORRESPONDENCE ...... 55

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City of Cut Bank SWDAR

INTRODUCTION

This Delineation and Assessment Report was prepared by Jim Stimson, a hydrogeologist with the Source Water Protection Program of the Montana Department of Environmental Quality (DEQ). Cut Bank public water supply (PWS) is located in Glacier County, Montana, about 110 miles north and west of Great Falls and about 30 miles west of Shelby (Figure 1). The DEQ PWS identification number, operator name, and operator number for the Cut Bank PWS appear on the title page of this report.

Purpose This report is intended to meet the technical requirements for the completion of the source water delineation and assessment report for the Cut Bank PWS as required by the Montana Source Water Protection Program (DEQ, 1999) and the federal Safe Drinking Water Act (SDWA) Amendments of 1996 (P.L. 104-182). The Montana Source Water Protection Program is intended to be a practical and cost- effective approach to the protection of public drinking water supplies from contamination. The primary purpose of this source water delineation and assessment report is to provide information to assist the Cut Bank PWS operator in the identification of potential contaminant sources near and upstream from the city’s intake, and to encourage the development of a source water protection plan to help protect the city’s drinking water for the long term.

Delineation and assessment constitute major components of the Montana Source Water Protection Program. Delineation entails mapping the boundaries of source water protection areas, which encompass ground water and/or surface waters contributing to public water supply sources. Assessment involves identifying locations or regions within source water protection areas where contaminants may be generated, stored, transported, or disposed, and determining the relative susceptibility of drinking water to contamination from these sources.

Limitations This report was prepared to assess threats to the Cut Bank public water supply and is based on published data including the most recent sanitary survey, and information obtained from local residents familiar with the community. The terms “drinking water supply” and “drinking water source” refer specifically to the sources of Cut Bank’s public water supply, and not any other public or private water supply. Also, not all of the potential or existing sources of groundwater or surface-water contamination in the area of Cut Bank are identified. Only potential sources of contamination in areas that contribute water to the identified drinking water sources are considered.

The term “contaminant” is used in this report to refer to constituents for which maximum concentration levels (MCLs) have been specified under the national primary drinking water standards, and to certain carcinogenic or toxic constituents that do not have MCLs but are considered to be significant health threats.

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CHAPTER 1 BACKGROUND

The Community Cut Bank is the county seat of Glacier County and is located about 50 miles east of the Rocky Mountain Front and next to Cut Bank Creek (Figure 1). State Highway 2, State Highway 214, and the Great Northern Rail line run near Cut Bank. The U.S. Census Bureau estimates the 2000 population of Glacier County at 12,600 people, 3,519 of whom reside in Cut Bank. The County’s population, as well as Cut Bank’s, has increased by about 4%, since 1990.

Cut Bank has its beginnings in 1890s when the Great Northern Railroad established a work camp to build the trestle over Cut Bank Creek. The railroad played a major role in Cut Bank’s continued growth, as did the cattle and sheep industries. Oil was discovered in the area in the 1920s and continues to be a major industry in the area today.

Within the city limits, residents obtain their drinking water from the municipal public water supply. The municipal sewer district services all residents within city limits and the wastewater treatment is applied in a multi-lagoon system located about 1 mile northeast of town (Figure 1). The water treatment plant is a conventional filtration plant with a maximum capacity of about 3 million gallons per day (MGD). Residents in areas outlying town limits where sewer services are not available utilize on-site septic systems for waste disposal. There are 4 other public water supplies in the area of which 2 are community systems and 2 are non-community (Figure 3). Three of the 4 public water supplies purchase water from Cut Bank and the other system uses ground water as its source of water.

Table 1. Public Water Supplies in the Cut Bank area. Figure 2. Cut Bank Average Temperatures and Precipitation

Climate Based on Western Regional Climatic Center data for the period of record, annual precipitation averages 12.61 inches. Monthly average precipitation ranges from 0.32 inches in February to 2.53 inches in June. Summer thunderstorms and winter snows provide a majority of the precipitation in the area. The annual mean snowfall in Cut Bank is 34.09 inches. A summary of the available climatic data for the Cut Page 2 City of Cut Bank SWDAR

Bank area is presented in Table 1 below.

Table 2. Climate Summary for the Cut Bank Airport.

Western Regional Climate Center, [email protected]

Geographic Setting Cut Bank is located in the glaciated Missouri Plateau that is a portion of the Great Plains physiographic province of North America. This area is also designated as the glaciated central ground-water region of the United States (Heath, 1984). The elevation at Cut Bank is approximately 3,800 feet above mean sea level and the town is located near Cut Bank Creek (Figure 1 and Figure 3). Cut Bank Creek flows through a gorge about 200 feet deep and about ¼ mile wide in the vicinity of the town of Cut Bank. Topographic relief in the area is low generally ranging between 20 and 100 feet.

Geology This section provides an overview of the geology and hydrology of the vicinity of Cut Bank. Information in this section comes primarily from Zimmerman (1967) and Alt and Hyndman (1986). The geology of the area can be used to determine the locations, boundaries, and hydraulic properties of local aquifers. An understanding of hydrogeologic conditions also provides an explanation for the sensitivity of local aquifers to potential contamination sources. Geology is not just important for understanding the hydrologic conditions related to ground water but it is also valuable for public water supplies that use surface water. For example, the timing and runoff patterns of are influenced in part by the geology within a watershed. Watersheds with large areas of low hydraulic conductivity bedrock tend to respond quickly to precipitation and snowmelt events. from streams within such a watershed show numerous high flow peaks or spikes. On the other hand, streams within watersheds underlain by bedrock that has high hydraulic conductivity tend to have more subdued hydrographs, that is, fewer and more rounded high flow peaks. of precipitation and snowmelt waters makes the high flow events rise more gradually and have more rounded peaks. Surface water quality can also be affected by the geology within a watershed and information in this section can be useful for gaining a better understanding of factors that control and sedimentation.

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Unconsolidated alluvium is limited in areal extend and for the most part it is not widely used to provide ground water. Where present, the alluvium consists of lenses of unconsolidated clay, sand, and gravel accumulated in close proximity to Cut Bank Creek and other small streams in the area.

Other younger (Quaternary age) are present in the area and include glacial lake deposits, glacial till, and glacial outwash deposits. Lake (lacustrine) deposits can be as much as 50 feet thick in some areas and are composed of varved clay, silt, sand and gravel (Zimmerman, 1967). Glacially derived sedimentary deposits listed above generally yield only small volumes of water to wells in locations where sand and gravel deposits dominate the package. In addition to the alluvium and glacially derived sediments there are also Quaternary deposits consisting of unconsolidated sediments beneath high level terraces and lower level terraces will yield water in some places where they are more extensive. The high level terraces are reported to yield water to wells especially on the irrigated lands west of Cut Bank.

Figure 4 is a regional geologic map for the area. Bedrock in the vicinity of Cut Bank is Upper Cretaceous in age. From youngest to oldest the geologic formations include the Two Medicine, Virgelle Sandstone, and Telegraph Creek. Silty sandstones and sandstone beds within the Two Medicine and Virgelle formations are widely used in the area to provide ground water for domestic and stock wells. The upper part of the Two Medicine Formation is primarily sandy shale and mudstone with some thin beds of sandstone; the lower 200 to 250 feet of the formation is fine-grained massive sandstone (Zimmerman, 1967). The Two Medicine Formation is reported to have a maximum thickness of 500 feet with water yield from is generally less than 10 gallons per minute. The Virgelle Sandstone is reported to be up to 180 feet thick and composed of massive sandstone with occasional beds of shale. Water yield to wells can be as high as 250 gallons per minute. Below the Virgelle Sandstone is a thick sequence of mostly dark-gray shale with some thin beds of limestone and some beds of bentonite. This is the Marias Shale that is part of a group of formations officially named the Colorado Group. The Marias Shale is reported to have a maximum thickness on the order of 1,995 feet (Zimmerman, 1967).

Ground-water flow within the Virgelle in the area is reported by Zimmerman (1967) to be from the southwest and the north in the vicinity of Cut Bank and recharge is primarily from infiltration of precipitation along formation outcrop and leakage between geologic formations.

The Public Water Supply The Cut Bank PWS is classified as a community system under the Federal Safe Drinking Water Act, because the system serves at least 25 year-round residents through at least 15 service connections. The PWS services almost 3,329 residents via approximately 1,474 active service connections.

Cut Bank Creek water is the source water for Cut Bank. The intakes for the system are located beneath the creek bed in the vicinity of the water treatment plant (Figure 1 and Figure 3). According to the most recent sanitary survey, the intakes are susceptible to plugging from high sediment events and have to be periodically “backwashed”. The water from the creek is treated through a conventional surface water treatment process and is disinfected by gas chlorination. There are two above ground storage reservoirs with total capacity of about 2,000,000 gallons. According to the most recent sanitary survey, multiple improvements and upgrades are needed for the Cut Bank Public Water Supply infrastructure that are specified in the Water System Capital Improvements Plan.

Due to the fact that Cut Bank obtains its drinking water from a surface water supply, the source water is classified as highly sensitive to contamination, in accordance with Montana Source Water Protection Page 4 City of Cut Bank SWDAR

Program criteria (1999). It is worth noting that in 1997 water thought to be contaminated with pig manure reached the surface water intakes and was brought into the water treatment plant. The exact location of the source of contamination is unknown and it is also not known where the source was within the Spill Response Region or the Watershed. However, this incident underscores the vulnerability of surface water to contamination and the importance for completing, and updating, an accurate inventories of potential contamination sources upstream from the public water supply intakes. In response to this event, the City of Cut Bank has developed a quick response plan to help identify where contamination originates.

Public water systems must conduct routine monitoring for contaminants in accordance with Federal Safe Drinking Water Act requirements. A community public water supply, like Cut Bank, must sample in accordance with schedules specified in the Administrative Rules of Montana (ARM). Monitoring includes coliform bacteria, lead, copper, nitrate, nitrite, volatile organic chemicals (including hydrocarbons and chlorinated solvents), inorganic chemicals (including metals), synthetic organic chemicals (including pesticides), and radiological contaminants. Transient, non-community PWSs are required to conduct routine monitoring only for pathogens (including coliform bacteria), nitrate, and nitrite. All contaminant concentrations detected in required samples must comply with numeric maximum contaminant levels (MCLs) specified in the Federal Safe Drinking Water Act.

The State of Montana classifies Cut Bank Creek as B-2 surface water. According to the classification, the Cut Bank Creek is to be maintained suitable for drinking, culinary and food- processing purposes after conventional treatment for the removal of naturally present impurities. These waters must also be maintained as suitable for bathing, swimming, and recreation; growth and propagation of salmonoid fishes and associated aquatic life, waterfowl, and furbearers; and agricultural and industrial water supply. These surface water classifications are pursuant to the Administrative Rules of Montana 17.30.600-625.

Cut Bank PWS Water Quality Within the past five years, no positive fecal coliform samples were collected during routine contaminant monitoring. No MCL exceedances were noted for any other constituents monitored over the past five years, this includes nitrate. The highest nitrate value recorded at the PWS is 1.48 milligrams per liter (mg/l) which is significantly below the MCL of 10 mg/l.

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CHAPTER 2 DELINEATION

The source water protection areas for the Cut Bank public water system are delineated in this chapter. The purpose of delineation is to map the source of water used by Cut Bank PWS and to define areas within which to prioritize source water protection efforts. Because Cut Bank uses Cut Bank Creek for its public water supply, two types of management regions are mapped; a spill response region and a watershed region.

The goal of management in the spill response region is to avoid introducing contaminants directly into the river upstream of the public water supply. In Figure 5. Daily flow for Cut Bank Creek addition, this region should be managed to prevent at Cut Bank. contaminants from reaching the intake or infiltration lines before natural processes reduce their concentrations. The goal of management in the watershed region is to maintain and improve water quality over long periods of time or increased usage.

Hydrogeologic Conditions The U.S. Geological Survey operates a gauging station at Cut Bank MT (Station 06099000). The station has a period of record extending from August 1905 to present. Annual average flow for the Cut Bank Creek at this station is 187 cubic feet per second (cfs). Maximum and minimum monthly for the same period are 327 and 80 cfs (NWISWeb Data for the Nation). The gage station data record the highest peak flow of 16,600 cfs in 1964. A for the last 5 years of record Figure 6. Frequency Analysis for Cut Bank Creek at Cut Bank. is shown to the right (Figure 5). The hydrograph shows a pattern of low flows in the fall and winter months and high flows during the and early summer.

Figure 6 shows the flood frequency curve with exceedance flows probability shown as a percent.

Using DEQ Source Water Protection Program criteria for ranking /source water sensitivity (Table 3 below), the Cut Bank PWS source water is considered highly sensitive to contamination. The sensitivity ranking is a result of the surface water source for the Cut Bank PWS.

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Table 3. Source water sensitivity criteria (DEQ, 1999). Source Water Sensitivity

High Source Water Sensitivity Surface water and GWUDISW Unconsolidated Alluvium (unconfined) Fluvial-Glacial Gravel Terrace and Pediment Gravel Shallow Fractured or Carbonate Bedrock Moderate Source Water Sensitivity Semi-consolidated Fill sediments Unconsolidated Alluvium (semi-confined) Low Source Water Sensitivity Consolidated Sandstone Bedrock Deep Fractured or Carbonate Bedrock Semi-consolidated Valley Fill Sediments (confined)

Conceptual Model and Assumptions The headwaters of Cut Bank Creek originate in the Rocky Mountains to the west in Glacier National Park. Significant to Cut Bank Creek include Spring Creek, Snake , Rocky Coulee, and the Red River.

Annual precipitation for the Cut Bank area is about 13 inches, however, precipitation is much higher in the mountainous headwaters. Annual precipitation can range between 40 and more than 85 inches in the higher mountain ranges. A significant portion of that precipitation occurs as snow during the winter months and as spring rain, both of which contribute to high streamflow events (Figure 2). Peak flows for Cut Bank Creek commonly occur in spring and early summer, and low flows are more common in late summer through the winter months.

Certain land uses and businesses located along Cut Bank Creek and its tributaries upstream from Cut Bank represent potential contaminant sources for the public water supply (Figure 3 and Figure 7). However, spills and leaks of contaminants are considered to represent a high hazard to the public water supply if they are located so that they result in direct discharge into Cut Bank Creek or into one of its tributaries upstream in the vicinity of the Cut Bank intake (Table 8). The concern is that spills or leaks occurring in closer proximity to the Cut Bank could reach the intake before plant operators can close or isolate the intake. This actually occurred in the 1997 incident mentioned above. Other contaminant sources may discharge to the river and its tributaries in a less direct manner. These contaminant sources are within the watershed but are farther from the river and contaminants can be flushed into the streams during spring snowmelt or storm events. Indirect discharge to streams can also come from contaminants that infiltrate into aquifers adjacent the river that then discharge to streams via hydraulic connections. Because these contaminants are not discharged directly into the river, they tend to pose a less immediate threat to the public water supply and are usually assigned a lower hazard rating.

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Seasonal timing of direct contaminant discharges into and streams can complicate the potential threat to the public water supply. Spills occurring during high water periods will tend to travel toward the surface water intake faster than during low water conditions. However, dilution during high flows in the spring and early summer may help reduce the hazard posed to the public water supply. Direct discharges to the river during low flow conditions will have less chance to be diluted before reaching the surface water intake.

Delineation Results

Spill Response Region The Spill Response Region for the City of Cut Bank extends 1/2 mile downstream and approximately 10 miles upstream of the surface water intake (Figure 3). It encloses the shoreline of Cut Bank Creek and also parts of several larger tributaries.

Watershed Region The Watershed Region for the Cut Bank intake encompasses the land area within the Cut Bank Creek Watershed (HUC 10030202) which is a sub-basin of the Marias Hydrologic Unit and upstream of Cut Bank (Figure 7 and Figure 8). The watershed has an area of 1,204 square miles.

Limiting Factors The delineations for the Cut Bank PWS Spill Response Region and Watershed Region are based on fixed- distance and watershed mapping. The Spill Response Region represents an approximation of the distance required for contaminants released upstream to reach the surface water intake with relatively short lag time. Numerous assumptions are associated with the Source Water Protection Program (SWPP) criteria for Spill Response Region delineations. Contaminant transport rates and concentrations will vary depending on stream/river flow conditions, groundwater flux into the river, contributions from overland flow, soil types, slope, characteristics of riparian vegetation, the extent of riparian vegetation buffer zones, the extent and duration of contamination, contaminant solution density, adsorption, mechanical dispersion, biological transformation, dilution, molecular diffusion, precipitation, oxidation, complexation, and volatilization. As a result, some areas within the Spill Response Region may be more conducive to contaminant transport than others, and should be designated as higher priority areas for source water protection efforts.

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CHAPTER 3 INVENTORY

An inventory of potential sources of contamination was conducted to assess the susceptibility of the Cut Bank PWS to contamination, and to identify priorities for source water protection planning. Inventories were conducted within the delineated Spill Response and Watershed Regions. The inventory focuses on facilities that generate, use, store, transport, or dispose of potential contaminants, and on land types on which potential contaminants are generated, used, stored, transported, or disposed. Additionally, the inventory identifies potential sources of all primary drinking water contaminants and Cryptosporidium. Only significant potential contaminant sources were selected for detailed inventory. The significant contaminants posing potential threats to the Cut Bank PWS include hazardous materials transported on railroads, interstates, and secondary roads; nitrate, pathogens, herbicides, and pesticides. The inventory for Cut Bank also focuses on all activities in the Spill Response Region, as well as general land uses and large potential contaminant sources in the Watershed 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. The following steps were followed:

Step 1: Land cover is identified from the National Land Cover Dataset compiled by the U.S. Geological Survey and U.S. Environmental Protection Agency (U.S.G.S., 2000). Land cover types in this dataset were mapped from satellite imagery at 30-meter resolution using a variety of supporting information.

Step 2: EPA’s Envirofacts System was queried to identify EPA regulated facilities. This system accesses the following databases: Resource Conservation and Recovery Information System (RCRIS), Biennial Reporting System (BRS), Toxic Release Inventory (TRI), Permit Compliance System (PCS), 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 is a significant potential contaminant source.

Step 3: DEQ databases were queried to identify Underground Storage Tanks (UST), hazardous waste contaminated sites, landfills, and abandoned mines.

Step 4: A business phone directory was consulted 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 Standard Industrial Codes.

Step 5: Major road and rail transportation routes were identified.

Step 6. All significant potential contaminant sources were identified in the inventory region and land uses and facilities that generate, store, transport, or dispose large quantities of hazardous materials were identified within the recharge region.

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Potential contaminant sources are designated as significant if they fall into one of the following categories:

1) Large quantity hazardous waste generators 8) Wastewater lagoons or spray irrigation 2) Landfills 9) Septic systems 3) Hazardous waste contaminated sites 10) Sewered residential areas 4) Underground storage tanks 11) Storm sewer outflows 5) Major roads or rail transportation routes 12) Floor drains, sumps, or dry wells 6) Cultivated cropland 13) Abandoned or active mines 7) Animal feeding operations

Inventory Results/Spill Response Region Table 4 summarizes the significant potential contaminant sources that are located within the Spill Response Region (Figure 3). The Cut Bank area has a fairly long history of oil and gas exploration and significant production. As stated previously, hydrocarbon reserves near Cut Bank were discovered in the 1920 and production continues to the present. Disposal of saline formation water associated primarily with oil production is an important issue relating to source water protection. In some parts of Montana, ground water has been negatively impacted by saline wastewater infiltrating from collection ponds and from re-injection into disposal wells. Oil and gas wells and test holes are fairly numerous in the area around Cut Bank and within the Spill Response Region (Figure 3). A potential problem related to the abandoned wells or test holes is, if they are not properly abandoned and plugged, they can also facilitate saline formation water entering other geologic formations that are used as aquifers and this will have a negative impact on the private and public water supplies. In addition, some aquifers may discharge to surface waters and improperly abandoned wells could contributed to an increased salinity of the surface water bodies. Past salt-water disposal practices and improperly abandoned oil wells and test holes are considered to be significant potential contaminant sources in this area.

Petroleum pipelines within the Spill Response Region and the watershed do represent significant potential contaminant sources due to the fact that they transport large volumes of petroleum products, and one of the lines crosses two tributaries to Cut Bank Creek (Figure 3). In addition, breaks in pipelines may not be detected immediately and can result in large volume releases.

There are no interstates or major highways within the Spill Response Region (Figure 1 and Figure 3). Railroad tracks operated by the Great Northern Railroad cross one of the distal portions of the Spill Response Region but do not directly cross the to Cut Bank Creek (Figure 3). Large volumes of hazardous materials are transported by rail and could pose a threat to the water supply. Based on the location of the rail way within the Spill Response Region, it does not appear to pose a significant threat to the public water supply.

Land areas within the spill response and watershed region are sparsely populated and fairly rural (Figure 7). The principal land cover in the Spill Response Region is ag-land (71%) and grassland (28%). Open water and wetland make up the remaining types of landcove. According to the Source Water Program criteria, the large percentage of agricultural land in this region indicates that activities on agricultural land represent a high potential threat to the Cut Bank PWS. The concern here is the potential for mismanagement or over- application of fertilizers and/or pesticides on the agricultural lands. Due to the large percentage of ag-lands within the Spill Response Region and watershed, there would be potential benefit to Cut Bank PWS, and other public water supplies in the watershed, to participate in and encourage the use of best management practices (BMPs) by the agricultural industry. Page 10 City of Cut Bank SWDAR

On the other hand, substantial areas of grassland are concentrated along Cut Bank Creek’s alluvial valley both within the Spill Response and the Watershed regions (Figure 7 and 8). The grassland areas are important because they act as a natural buffer between the ag-lands and the creek, and would help slow or prevent the direct access of excess fertilizer and other ag-chemicals to the streams (Figure 7).

Other businesses and land uses in the area are also considered as potential sources of contamination. Some of these sites are located down-stream from the intake location (Figure 3). Potential contaminant sources downstream of the intake are not considered to pose a threat to the Cut Bank PWS. This includes several industrial and municipal wastewater discharge points, underground storage tanks (USTs), and two State Superfund Sites. It could also include Class V injection wells (floor or “French” drains) but an accurate survey of the Class V wells does not exist at this time. A full listing of businesses in and around the Cut Bank, based on the Standard Industrial Codes (SIC) codes is presented in Appendix A. Some of these businesses could also be considered potential contaminant sources that pose a threat to other public water supplies in the area. This is because they are located relatively close the other public water supplies (Figure 3 and Table 1). In the Cut Bank area there is only one other public water supply that will have a Source Water Delineation and Assessment Report SWDAR) completed, the others purchase water from Cut Bank. The SWDAR for the Airport well will address hazards and concerns with significant potential contaminant sources.

Table 4. Significant potential contaminant sources in the Spill Response Region for the Cut Bank PWS. Potential ID Number Potential Contaminants Hazard Source On Maps Migration of brine wastewater into shallow Gas and Oil Total Dissolved Solids, Petroleum 1 groundwater discharging to surface water, Wells Hydrocarbons to surface water Pipelines 2 Petroleum Products Spills and leaks Spills, storm water runoff, infiltration into Railroad 3 Pesticides, fertilizers, VOCs, other ground water Erosion and mobilization of metals in sediment Mining Not Metals and/or leached into surface water and Operations Numbered groundwater Cultivated Not Fertilizers, pesticides, pathogens, Spills, over application, surface runoff Cropland Numbered nitrate Assorted Releases or spills, mishandling of chemicals, Not VOCs, SOCs, petroleum hydrocarbons, businesses in improper disposal of chemicals anywhere near Numbered metals, pathogens, nitrate town the river Class V Leaks, spills, improper handling and Injection disposal/discharge of chemicals used by Wells Not VOCs, SOCs, petroleum hydrocarbons, various businesses and are released to systems (existence and Numbered metals, pathogens, nitrate that allow infiltration of contaminants to the locations are subsurface or to the storm water system not known)

From the above list of potential contaminant sources, some are considered significant based upon the following factors: the volume of potential releases, the volume of hazardous materials typically handled, the potential of the released materials to impact nearby surface water or groundwater, and the proximity of the sources to the PWS surface water intakes. Significant potential contaminant sources

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from the above list are discussed individually in the following section on susceptibility assessment and they are listed in Table 8.

Inventory Results/Watershed Region As in the Spill Response Region, the transportation corridors for rail and highways within the watershed do not appear to pose a significant threat to Cut Bank’s water supply (Figure 3). At least one petroleum pipeline within the watershed represents a significant potential contaminant source due to the fact that it transports large volumes of petroleum products, and crosses several of the tributaries to Cut Bank Creek. The concern is that breaks in pipelines may not be detected immediately and can result in large volume releases.

It should be noted that assessing the hazard of spills and releases from any of the above sources could be complicated by the flow conditions present when the contaminants enter the creek. Spills that reach the creek during low flow conditions would tend to remain more intact and concentrated because there is less creek water to dilute the contaminant plume. Low flow conditions are usually less turbulent and accomplish less mixing. On the other hand, spills occurring during low flow conditions would move more slowly which would give public water supply operators more time to respond to the threat. Spills entering the creek during high flow conditions would move more rapidly downstream but more turbulent flow would result in more effective mixing and dilution of the contaminant plume into the creek water.

Predominant land covers in the Watershed Region include ag-land (49%) and grassland (48%), and forest (3%) (Figure 9). The agricultural landcover within the watershed is for the most part not concentrated in the stream valleys. For this reason, activities on agricultural land are not considered to pose as great a potential threat to the public water supply as they would if the ag-lands were concentrated in close proximity to the streams and the stream valleys.

One Confined Animal Feeding Operation (CAFO) is identified in the Watershed Region but it does not appear to be located on at tributary to Cut Bank Creek. However, an informal review of aerial photographs or images along Cut Bank Creek and some of its tributaries indicates there are several corrals, farm parcels, and at least one Hutterite Colony located fairly near the creek and some of its tributaries. Due to their distance from the Cut Bank intakes it would appear that these potential contaminant sources would not pose an immediate threat to the public water supply. On the other hand, the 1997 “pig event” suggests that under certain conditions, animal feeding or containment sites do pose a real threat to the source water.

Most of the other significant potential contaminant point sources in the watershed are located southeast of Cut Bank’s intake, or they are concentrated in the Browning area (Figure 8). These include a number of storm and wastewater discharges, landfills, underground fuel storage tanks, a crude oil pipeline, mining claims and sites, oil and gas test wells, and others (Table 5). It also includes Class V injection wells but the number and exact locations of these wells is unknown. If spills or releases occur at some these locations, it could result in a contaminants released directly into the creek or into the shallow aquifer system that very likely is in hydraulic connection with the creek. Under certain flow conditions, the contaminants could be discharged from the shallow aquifer system into the river. Unless the quantities released were large, the majority of the potential contaminant sources in the watershed are located far enough away from Cut Bank so as not to pose an acute threat to the public

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water supply (Figure 8). A full listing of businesses in the City of Cut Bank (based on SIC codes) was compiled and is present in Appendix A.

Low septic densities dominate the Watershed Region with higher density areas in and around Browning and Cut Bank. Table 5 below lists the significant potential contaminant sources identified in the Watershed Region.

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Table 5. Significant potential contaminant sources in the Watershed Region Cut Bank PWS ID Potential Number Potential Contaminants Hazard Source on Maps Migration of brine wastewater into Gas and Oil shallow groundwater discharging to 1 Total Dissolved Solids, Petroleum Hydrocarbons Wells surface water, surface runoff to surface water Pipelines 2 Petroleum Products Spills and leaks Spills, storm water runoff, infiltration into Railroad 3 Pesticides, fertilizers, VOCs, other ground water State Spills and storm water runoff to surface Superfund 4 Multiple sites in the Cut Bank and Browning areas water, infiltration into ground water Site Confined Animal Storm water runoff, infiltration into Feeding 5 Nitrate, pathogens shallow ground water. Operation (CAFO) Erosion and mobilization of metals in Mining Not Metals, acid mine runoff, increased suspended and sediment and/or leached into surface Operations Numbered in streams water and groundwater Cultivated Not Fertilizers, pesticides, pathogens, nitrate Spills, over application, surface runoff Cropland Numbered Infiltration of leachate into shallow Not Metals, Inorganics, VOCs, SOCs, pathogens, groundwater and subsequent discharging Landfills Numbered nitrate to Cut Bank Creek; unauthorized dumping Not Spills, leaks impacting groundwater and USTs/LUSTs VOCs, petroleum hydrocarbons Numbered or reaching surface water Leaks, spills, improper handling and disposal/discharge of chemicals used by Storm Water / Not various businesses and are released to Wastewater VOCs, SOCs, pathogens, nitrate, TDS Numbered systems that allow discharge of Discharges contaminants with wastewater to surface water Assorted Releases or spills, mishandling of Not VOCs, SOCs, petroleum hydrocarbons, metals, businesses in chemicals, improper disposal of Numbered pathogens, nitrate town chemicals anywhere near the river Class V Leaks, spills, improper handling and Injection disposal/discharge of chemicals used by Wells Not VOCs, SOCs, petroleum hydrocarbons, metals, various businesses and are released to (existence Numbered pathogens, nitrate systems that allow infiltration of and locations contaminants to the subsurface or to the are not storm water system known) From the above list of potential contaminant sources, some are considered significant based upon the following factors: volume of potential releases, the volume of hazardous materials typically handled, the potential of the released materials to impact nearby surface water or groundwater, and the proximity of the sources to the PWS surface water intakes. Page 14 City of Cut Bank SWDAR

Inventory Update To make this SWDAR a useful document in the years to come, the owners, manager, or the certified water system operator(s) for the public water supply for the Cut Bank should update the inventory for their records every year. Changes in land uses or potential contaminant sources should be noted and additions made as needed. The complete inventory should be submitted to DEQ at least every 5 years to ensure that this report/plan stays in the public record.

Inventory Limitations The extent of the potential contaminant source inventory is limited in several respects. The inventory is based on data readily available through state documents, published reports, and GIS data. Documentation may not be readily available on some potential sources. As a result, all potential contaminant sources may not have been identified. In some instances, inadequate location information precluded the inclusion of potential sources in the inventory.

Page 15 City of Cut Bank SWDAR

CHAPTER 4 SUSCEPTIBILITY ASSESSMENT

Susceptibility of the Cut Bank PWS's source water is determined by two factors: the potential of a contaminant reaching the intake and the resulting health hazard. Susceptibility is assessed in order to prioritize potential pollutant sources in the Spill Response Region in order to guide management actions undertaken by local entities, in this case Cut Bank and Glacier County.

The goal of source water management is to protect the source water, manage significant potential contaminant sources in the Spill Response Region, and ensure that land use activities in the Watershed Region pose minimal threats to the source water. Management priorities in the Spill Response 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 Cut Bank PWS operators and the community to reduce susceptibility are also included in this section of the report.

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 reach the PWS intake. The hazard presented by point sources of contaminants in Cut Bank’s Spill Response Region depends on whether contaminants can discharge directly into the Cut Bank or into its tributaries. Point source hazard is also dependent on the health affects associated with potential contaminants. Hazard ratings for point and nonpoint sources are assigned based on criteria listed in Table 6. Barriers can be anything that decreases the likelihood that contaminated water will reach Cut Bank’s surface water intake. Examples of barriers include: a vegetated riparian area, protective forest management practices, and dilution.

Table 6. Hazard of Potential Contaminant Sources, Determination of For Surface Water Sources

Potential High Hazard Rating Moderate Hazard Rating Low Hazard Rating Contaminant Sources Point Sources of Potential for direct discharge Potential for discharge to Potential contaminant sources Nitrates or to surface water groundwater hydraulically in the watershed region Pathogens connected to surface water

Point Sources of Potential for direct discharge Potential for direct discharge Potential for discharge to VOCs, SOCs, or of large quantities from roads, of small quantities to surface groundwater hydraulically Metals rails, or pipelines water connected to surface water

Septic Systems More than 50 – 300 Less than (density) 300 per sq. mi. per sq. mi. 50 per sq. mi.

Municipal Sanitary More than 50 percent of 20 to 50 percent Less than 20 percent of region Sewer region of region (percent land use)

Page 16 City of Cut Bank SWDAR

Table 6. Hazard of Potential Contaminant Sources, Determination of For Surface Water Sources

Potential High Hazard Rating Moderate Hazard Rating Low Hazard Rating Contaminant Sources Cropped More than 50 percent of 20 to 50 percent Less than 20 percent of region Agricultural Land region of region (percent land use)

Barriers to contamination can be anything that decreases the likelihood that contaminants will reach a surface water intake, spring or well. Barriers can be engineered structures, management actions, or natural conditions. Examples of engineered barriers are spill catchment structures for industrial facilities and leak detection for underground storage tanks. Emergency planning and best management practices are considered management barriers. Thick clay-rich soils, a deep water table or a thick saturated zone above the well intake can be natural barriers.

Table 7. Susceptibility of Source Water based on Hazard rating and the presence of Barriers High Hazard Rating Moderate Hazard Low Hazard Rating Rating Very High High Moderate No Barriers Susceptibility Susceptibility Susceptibility High Moderate Low One Barrier Susceptibility Susceptibility Susceptibility Moderate Low Very Low Multiple Barriers Susceptibility Susceptibility Susceptibility

Susceptibility ratings are presented individually for each significant potential contaminant source and each associated contaminant on the following page (Table 8).

Page 17 City of Cut Bank SWDAR Susceptibility Assessment Results Table 8. Susceptibility Assessment Significant Potential Contaminant Sources in the Spill Response and Watershed Regions Cut Bank PWS surface water intakes Spill Response Region

Source ID Contaminant Hazard Hazard Barriers Susceptibility Management Recommendations Number Rating on Maps Migration of brine Moderate -None High Monitor drilling activities, oil field wastewater into Total Dissolved development, and wastewater disposal shallow groundwater Gas and Oil Solids, practices near or adjacent the Spill Response 1 discharging to Wells Petroleum Region. surface water, Hydrocarbons surface runoff to surface water High -Leak detection Moderate Maintain preparedness of local emergency -Dilution at locations farther personnel through active training, storm Petroleum water diversion Pipelines 2 Spills and leaks away from the intake; Products -County Emergency Response, training and preparation of local response personnel. Fertilizers, Spills, over High -Substantial Grassland buffers Moderate Support providing educational information, Cultivated Not pesticides, application, surface materials and resources to land owners on the Cropland Numbered pathogens, runoff proper application and storage of pesticide nitrate and fertilizers; implement agricultural BMPs Moderate -Dilution at some locations Low Maintain preparedness of local emergency Pesticides, Spills, storm water farther away from the intake; personnel through active training, Railroad 3 fertilizers, runoff, infiltration -County Emergency Response, VOCs, other into ground water training and preparation of local response personnel Erosion and Low -Dilution Low Continue monitoring for metals and mobilization of -Most locations are small, participate in watershed-wide efforts to Mining Not metals in sediment Metals undeveloped or extract gravel maintain water quality and clean up high Operations Numbered and/or leached into priority abandoned mines. surface water and groundwater

Page 18 City of Cut Bank SWDAR Table 8. Susceptibility Assessment Significant Potential Contaminant Sources in the Spill Response and Watershed Regions Cut Bank PWS surface water intakes Spill Response Region

Source ID Contaminant Hazard Hazard Barriers Susceptibility Management Recommendations Number Rating on Maps VOCs, SOCs, Releases or spills, Low -Some are located downstream of Low to Very Support providing educational workshops petroleum mishandling of the PWS intake Low provided to the general public by the city, Assorted Not hydrocarbons, chemicals, improper - Volumes of potential county, or state promote safe handling and businesses in Numbered metals, disposal of contaminants are relatively small proper storage, transport, use, and disposal of town pathogens, chemicals anywhere hazardous materials. Scheduled days for the nitrate near the river collection of hazardous wastes from the public Leaks, spills, Unknown -Unknown Unknown Inventory; Provide educational information, improper handling materials and resources to business owners and and the public on proper waste disposal and Class V VOCs, SOCs, disposal/discharge of recycling Injection petroleum chemicals used by Wells Not hydrocarbons, various businesses (existence and Numbered metals, and are released to locations are pathogens, systems that allow not known) nitrate infiltration of contaminants to the subsurface or to the storm water system Watershed Region Source ID Contaminant Hazard Hazard Barriers Susceptibility Management Recommendations Number Rating on Maps Spills and storm Multiple sites in Low -Cut Bank area sites are Low Continue monitoring and encourage state and State water runoff to the Cut Bank downstream of intake local officials to proceed to have site Superfund 4 surface water, and Browning -Browning area sites are over 30 mitigated. Site infiltration into areas miles west of Cut Bank ground water

Page 19 City of Cut Bank SWDAR Table 8. Susceptibility Assessment Significant Potential Contaminant Sources in the Spill Response and Watershed Regions Cut Bank PWS surface water intakes Spill Response Region

Source ID Contaminant Hazard Hazard Barriers Susceptibility Management Recommendations Number Rating on Maps Confined Storm water runoff, Low to -More than 10 miles west of Cut Low to -Continue monitoring, encourage best Animal Nitrate, infiltration into Moderate Bank Moderate management practices for CAFOs Feeding 5 pathogens shallow ground -Based on past history, vigilance is warranted Operation water. (CAFO) Infiltration of Low -Cut Bank site is closed and Low -Continue monitoring leachate into shallow Metals, down stream from intake groundwater and Inorganics, -Other sites are more than 20 Not subsequent Landfills VOCs, SOCs, miles west of Cut Bank Numbered discharging to Cut pathogens, Bank Creek; nitrate unauthorized dumping Spills, leaks Low -Cut Bank area sites are Low Spill response planning, tank and VOCs, impacting Not downstream of intake groundwater monitoring, spill catchment, USTs/LUSTs petroleum groundwater and or Numbered -Browning area sites are over 30 active and ongoing remediation of spill sites hydrocarbons reaching surface miles west of Cut Bank water Leaks, spills, Low -Cut Bank area sites are Low Ensure proper maintenance and operation of improper handling downstream of intake system; monitor leaks in system; develop an and -Browning area sites are over 30 emergency plan in the event of system failure disposal/discharge of miles west of Cut Bank chemicals used by Storm Water / VOCs, SOCs, Not various businesses Wastewater pathogens, Numbered and are released to Discharges nitrate, TDS systems that allow discharge of contaminants with wastewater to surface water

Page 20 City of Cut Bank SWDAR Table 8. Susceptibility Assessment Significant Potential Contaminant Sources in the Spill Response and Watershed Regions Cut Bank PWS surface water intakes Spill Response Region

Source ID Contaminant Hazard Hazard Barriers Susceptibility Management Recommendations Number Rating on Maps Municipal Pathogens, Leaks in sewer Low -City’s treatment facilities are Low Ongoing testing and maintenance of lines and Sewer nitrate mains to down-stream from the intake system, replacement of old lines, compliance System groundwater, -The mouth of Old Maid Coulee with current regulations for discharges Not which may reach appears to be downstream of the Numbered surface water, intakes. direct releases from lagoons to Old Maid Coulee

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The susceptibility assessment results for each significant potential contaminant source identified is described below:

Oil Wells and Test Hole- Petroleum exploration activities in the Cut Bank area have been extensive in the past 80 years. Numerous test holes and exploratory wells have been completed in the area. Most of this activity has been focused in a area just west of Cut Bank (Figure 8). Due to the number of oil and gas wells and test holes in the area, and the inability to determine if they have been properly abandoned, the wells are considered to represent a moderate hazard and with no barriers identified susceptibility is rated as high.

Petroleum Pipeline – The potential hazard represented by releases, spills, and leaks from pipelines within the watershed is high because the pipeline crosses several tributaries to Cut Bank Creek. Susceptibility of the public water supply to the pipeline is moderate with the multiple barriers identified including leak detection and emergency reponse.

Agricultural lands – The potential hazard from pathogens and nitrate originating from agricultural lands is moderate. Cropped agricultural lands occupy a significant part of the Spill Response Region and Watershed Region. The susceptibility of the intake to the agricultural land is also moderate because significant areas of grassland lie between the ag-land and the Cut Bank Creek valley and tributary valleys.

Railroads – The potential hazard represented by pesticides, fertilizers, VOCs and SOCs from spills along the Great Northern railway pose a moderate hazard. As noted previously, the railroad is not in close proximity to the Cut Bank Creek or its tributaries. Susceptibility of the Cut Bank PWS to this potential contaminant source is interpreted to be low.

Mining Operations- Based on available information, the mining operations in the area are relatively small or simply represent undeveloped claims. Others are simply relatively small gravel pits. Due to their size and distance from the public water supply intake they are not considered to pose a threat to the water supply. The susceptibility is rated as low.

Assorted Businesses in Town- Appendix A lists various businesses in town that are considered to represent potential contaminant sources based on the criteria within the Source Water Protection Guidelines (DEQ, 1999). Based on their location with respect to the public water supply intake, these businesses are not considered to pose a threat to the water supply. However, a simple proactive step to reducing the risk of unnecessary contamination in a community is to provide educational information and resources to business owners and the public on proper waste disposal and recycling.

Class V Injection Wells – The potential hazard imposed by VOCs, SOCs, pathogens, nitrate, and other contaminants originating from the class V injection wells is considered low. The susceptibility of the intake to contaminants originating from this source is unknown due to the fact that no inventory of Class V well is complete or the current inventory is inadequate.

State Superfund Sites – There are several sites located in Cut Bank downstream from the surface water intakes and several other sites located near Browning more than 30 miles west of Cut Bank. Due to their location and distance from the Cut Bank surface water intakes, these sites are assigned a low hazard and low susceptibility.

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Confined Animal Feeding Operations- One Confined Animal Feeding Operation (CAFO) is identified in watershed about 20 miles west of Cut Bank. On June 10, 1974, the federal Environmental Protection Agency (EPA) delegated authority to Montana for administration of the Montana Pollutant Discharge Elimination System (MPDES). The MPDES issues permits to control point source discharges of pollution. A CAFO is defined in Section 502 of the Clean Water Act as a point source of pollution. Discharges from CAFOs require a permit. Due to the location, distance, and permit requirement, hazard and susceptibility for this site would be rated as low. However, the incident in 1997 mentioned previously illustrates that Cut Bank Creek and the Cut Bank Public Water Supply are susceptible to contamination from wastes from animal containment and feeding facilities. Susceptibility is therefore rated as low to moderate.

Landfills – Multiple landfills are identified within the watershed. Most are small and closed. In addition, due to their location the do not pose a threat to the public water supply. Hazard is low and susceptibility is low.

UST/LUSTs- The potential hazard imposed by VOCs and petroleum hydrocarbons is low. This is because most of the underground tanks are located either a significant distance up-stream of the intake, or are located in Cut Bank down-stream of the intake. The susceptibility is rated very low due to the presence of several barriers including spill prevention, dilution, ongoing monitoring of ground water and monitoring for spills.

Wastewater Discharges- The potential hazard from VOCs, SOCs, pathogens, and nitrate originating from wastewater discharges is moderate. The susceptibility of the PWS intake to contaminants originating from these sources is low. The primary reason for the low rating is that the discharge points are either downstream from the public water supply intake, or a significant distance up-stream.

Municipal Sewer System – The potential hazard imposed by pathogens and nitrate originating from Cut Bank’s municipal sewer system is low. The plant is located about one mile northeast of town near Old Maid Coulee. If a release from the lagoons occurred, the Old Maid Coulee appears to join Cut Bank Creek downstream of the surface water intakes. The susceptibility of the intakes to nitrate and pathogens originating from this source is rated as low.

It should be noted that even small releases of some chemicals in close proximity to a surface water intake can have significant negative impact on water quality, and is therefore a significant threat to the public water supply. Steps can be taken to reduce the likelihood of releases in the source water for the PWS or in the vicinity of the sources. Some of these steps (considered management recommendations) are listed below.

Management Recommendations Management recommendations are included in the susceptibility table for the Cut Bank PWS (Table 8). If these management recommendations are implemented, they may be considered additional barriers that will reduce the susceptibility of the intake to specific sources and contaminants.

Management recommendations fall into the following categories:

• Agricultural best management practices • management

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• Proper disposal and monitoring of oil and gas production wastewater • Education • Emergency Response Planning

Agricultural and silvicultural best management practices (BMPs) – BMPs that address application and mixing of fertilizer and pesticides are a viable alternative to prohibition of their use. BMPs may also be utilized to minimize surface runoff and on cultivated fields. , selective logging, and other silvicultural practices (essentially BMPs) should be considered on a county-wide basis. BMPs are generally voluntary but their implementation can be encouraged through education and technical assistance. County planning can help promote the implementation of BMP on lands that are outside city limits but indirectly affect the city PWS.

Stormwater management . Stormwater planning should address source and drainage control. Source control can be accomplished through educational programs focusing on residential and commercial chemical use, disposal, and recycling. Drainage control and pollutant removal can be accomplished through the use of vegetated detention basins at outfall locations.

Proper disposal and monitoring of oil and gas production wastewater – Companies and oil field operators should adhear to regulations for proper disposal set forth by the underground injection control program of the Safe Drinking Water Act. This Act was established to protect underground sources of drinking water from contamination by industrial operations. In addition, city and county officials can apply to the Montana Board of Oil and Gas Conservation for grants to help pay for properly abandoning oil and gas wells. Abandoned wells that represent the greatest threat to the environment and public health and safety are given priority over other wells.

Education - Educational workshops provided to the general public by the city, county, or state promote safe handling and proper storage, transport, use, and disposal of hazardous materials. Ongoing training provided to designated emergency personnel will promote the efficiency and effectiveness of emergency responses to hazardous material spills. Likewise, educational workshops provided to rural homeowners will promote the proper maintenance and replacement of residential septic systems. The EPA and the State of Montana can provide educational materials on these topics.

Hazardous Materials Collection Days – Several counties in the state that have vulnerable water supplies have implemented scheduled days for the collection of hazardous wastes from the public. These vary in the inclusiveness of what materials are collected, how the materials are handled, and how they are disposed of, but they all act to reduce the amount of unauthorized or improper disposal of these wastes. Used motor oil collection station could be established and available to the public on a regular basis.

Emergency Response Plan – Several counties have compiled Emergency Response Plans that were then adopted by the local communities. The usefulness and effectiveness of a response plan are maximized if it contains a clear listing of all emergency contacts, emergency numbers, and resources available within the county to respond to an emergency situation, such as a hazardous material spill. Emergency plans are not difficult to develop or distribute, but have a significant benefit to the citizens and municipalities within the county.

Page 24 City of Cut Bank SWDAR

The City’s PWS operators, the city administration, and the Glacier County administration should consider these management recommendations. Should contamination reach the town's intake, the City and County will likely need to work cooperatively to address remediation or relocation of the intake.

Page 25 City of Cut Bank SWDAR

CHAPTER 5 Monitoring Waivers

Waiver Recommendation The city of Cut Bank has a wavier for Phase 2 inorganic constituents that include Barium, Cadmium, Chromium, Fluoride Mercury, and Selenium. Based on past monitoring results or the susceptibility assessment of the intake, Cut Bank PWS may not be eligible for additional monitoring waivers. However, to be sure that eligibility for all available waivers is considered, the PWS Operators are encouraged to carefully review the following section on Monitoring Waiver Requirements. If after reviewing this section it is determined that an additional waivers are feasible, the Cut Bank PWS should submit a letter with the proper documentation to DEQ requesting monitoring waivers. Table 9 shows how identified potential contaminant sources affect the eligibility for monitoring waivers.

Table 9. Susceptibility Assessment as it relates to waiver eligibility for significant potential contaminant sources in the Spill Response Region Cut Bank PWS surface water intakes. Source Contaminant Susceptibility Waiver Eligibility

Oil Wells and Test Holes Total Dissolved Solids (TDS), High The number of drilling Petroleum, activity in the watershed Hydrocarbons likely precludes a waiver Petroleum Pipelines Fuels, Hydrocarbonsbg Moderate The number of pipelines and the volume of petroleum products transported likely precludes a waiver Cultivated Cropland Fertilizers, pesticides, pathogens, Moderate Chemical use likely nitrate precludes waivers for some chemicals Railroad Pesticides, fertilizers, VOCs Low Chemical use likely precludes waivers for some chemicals Mining Operations Metals Low System has a Phase 2 Waiver, Most mines are small or extract gravel, applying for a Phase 5 waiver may be warranted. Assorted Businesses in Town VOCs, SOCs, petroleum Very Low Chemical use likely hydrocarbons, metals, pathogens, precludes waivers for some nitrate chemicals Waivers are not available for pathogens and nitrate UST/LUSTs VOCs, petroleum hydrocarbons Very Low Presence of sites with historic leaks within Cut Bank likely precludes waivers Wastewater Discharges VOCs, SOCs, pathogens, nitrate, Low to Very Waivers are not available TDS Low for pathogens and nitrate

Page 26 City of Cut Bank SWDAR

Source Contaminant Susceptibility Waiver Eligibility

Municipal Sewer System Pathogens, nitrate Low to Very Waivers are not available Low for pathogens and nitrate Class V Injection Wells VOCs, SOCs, pathogens, nitrate Very Low Waivers are not available for pathogens and nitrate

Monitoring Waiver Requirements The 1986 Amendments to the Safe Drinking Water Act require that community and non-community PWSs sample drinking water sources for the presence of volatile organic chemicals (VOCs) and synthetic organic chemicals (SOCs). The US EPA has authorized states to issue monitoring waivers for the organic chemicals to systems that have completed an approved waiver application and review process. All PWSs in the State of Montana are eligible for consideration of monitoring waivers for several organic chemicals. The chemicals diquat, endothall, glyphosate, dioxins, ethylene dibromide (EDB), dibromochloropropane (DBCP), and polychlorinated biphenyls are excluded from monitoring requirements by statewide waivers.

Use Waivers A Use Waiver can be allowed if through a vulnerability assessment, it is determined that specific organic chemicals were not used, manufactured, or stored in the area of a water source (or source area). If certain organic chemicals have been used, or if the use is unknown, the system would be determined to be vulnerable to organic chemical contamination and ineligible for a Use Waiver for those particular contaminants.

Susceptibility Waivers If a Use Waiver is not granted, a system may still be eligible for a Susceptibility Waiver, if through a vulnerability assessment it is demonstrated that the water source would not be susceptible to contamination. Susceptibility is based on prior analytical or vulnerability assessment results, environmental persistence, and transport of the contaminants, natural protection of the source, wellhead protection program efforts, and the level of susceptibility indicators (such as nitrate and coliform bacteria). The vulnerability assessment of a surface water source must consider the watershed area above the source, or a minimum fixed radius of 1.5 miles upgradient of the surface water intake. PWSs developed in unconfined aquifers should use a minimum fixed radius of 1.0 mile as an area of investigation for the use of organic chemicals. Vulnerability assessment of spring water sources should use a minimum fixed radius of 1.0 mile as an area of investigation for the use of organic chemicals. Shallow groundwater sources under the direct influence of surface water (GWUDISW) should use the same area of investigation as surface water systems; that is, the watershed area above the source, or a minimum fixed radius of 1.5 miles upgradient of the point of diversion. The purpose of the vulnerability assessment procedures outlined in this section is to determine which of the organic chemical contaminants are in the area of investigation.

Given the wide range of landforms, land uses, and the diversity of groundwater and surface water sources across the state, additional information is often required during the review of a waiver application. Additional information may include well logs, pump test data, or water quality monitoring data from surrounding public water systems; delineation of zones of influence and contribution to a well; Time-of- Travel or attenuation studies; vulnerability mapping; and the use of computerized groundwater flow and transport models. DEQ’s PWS Section and DEQ’s Source Water Protection Program will conduct review of an organic chemical monitoring waiver application. Other state agencies may be asked for assistance.

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Susceptibility Waiver for Confined Aquifers Confined groundwater is isolated from overlying material by relatively impermeable geologic formations. A confined aquifer is subject to pressures higher than atmospheric pressure that would exist at the top of the aquifer if the aquifer were not geologically confined. A well that is drilled through the impervious layer into a confined aquifer will enable the water to rise in the borehole to a level that is proportional to the water pressure (hydrostatic head) that exists at the top of a confined aquifer.

The susceptibility of a confined aquifer relates to the probability of an introduced contaminant to travel from the source of contamination to the aquifer. Susceptibility of an aquifer to contamination will be influenced by the hydrogeologic characteristics of the soil, vadose zone (the unsaturated geologic materials between the ground surface and the aquifer), and confining layers. Important hydrogeologic controls include the thickness of the soil, the depth of the aquifer, the permeability of the soil and vadose zones, the thickness and uniformity of low permeability and confining layers between the surface and the aquifer, and hydrostatic head of the aquifer. These factors will control how readily a contaminant will infiltrate and percolate toward the groundwater.

The Susceptibility waiver has the objective of assessing the potential of contaminants reaching the groundwater used by the PWS. A groundwater source that appears to be confined from surface infiltration in the immediate area of the wellhead may eventually be affected by contaminated groundwater flow from elsewhere in the recharge area. Contaminants could also enter the confined aquifer through improper well construction or abandonment where the well provides a hydraulic connection from the surface to the confined aquifer. The extent of confinement of an aquifer is critical to limiting susceptibility to organic chemical contamination. Regional conditions that define the confinement of a groundwater source must be demonstrated by the PWS in order to be considered for a confined aquifer susceptibility waiver. Confinement of an aquifer can be demonstrated by pump test data (storage coefficient), geologic mapping, and well logs. Site specific information is required to sufficiently represent the recharge area of the aquifer and the zone of contribution to the PWS well. The following information should be provided: • Abandoned wells in the region (zone of contribution to the well), • Other wells in the region (zone of contribution to the well), • Nitrate/Coliform bacteria analytical history of the PWS well, • Organic chemical analytical history of the PWS well,

Susceptibility Waiver for Unconfined Aquifers Unconfined aquifers are the most common source of usable groundwater. Unconfined aquifers differ from confined aquifers in that the groundwater is not regionally contained within relatively impervious geologic strata. As a result, the upper groundwater surface or water table in an unconfined aquifer is not under pressure that produces hydrostatic head common to confined aquifers.

Unconfined aquifers are usually locally recharged from surface water or precipitation. In general, groundwater flow gradients in unconfined aquifers reflect surface topography, and the residence time of water in the aquifer is comparatively shorter than for water in confined aquifers. Similar water chemistry often exists between unconfined groundwater and area surface water, and physical parameters and dissolved constituents can be an indicator of the hydraulic connection between groundwater and surface water. Consequently, unconfined aquifers can be susceptible to contamination by organic chemicals migrating from the ground surface to groundwater.

Page 28 City of Cut Bank SWDAR

The objective of the susceptibility waiver application is to assess the potential of organic chemical migration from the surface to the unconfined aquifer. The general procedures make use of a combination of site specific information pertaining to the location and construction of the source development, monitoring history of the source, geologic characteristics of the unsaturated soil and vadose zones, and chemical characteristics of the organic chemicals pertaining to their mobility and persistence in the environment. The zone of contribution of the unconfined groundwater source must be defined and plotted. This should describe the groundwater flow directions, gradients, and a 3-year time-of-travel. All surface bodies within 1,000 feet of the PWS well(s) must be plotted. Analytical monitoring history of the PWS well and those nearby should be provided as well.

Page 29 City of Cut Bank SWDAR

REFERENCES Alt, David, and Hyndman, Donald W., 1990, Roadside Geology of Montana, Mountain Press Publishing Company, Missoula.

Alt, David, and Hyndman, Donald W., 1998, Northwest Exposures, A Geologic Story of the Northwest, Mountain Press Publishing Company, Missoula.

Board of Water Well Contractors, Administrative Rules of Montana, 01/30/2001. 36.21.656-.660

Department of Environmental Quality, 1999. Montana Source Water Protection Program, Approved by EPA in November 1999, inclusive of personal communications with Joe Meek & others.

DEQ Permitting and Compliance Division, 2001. Sanitary Survey for Cut Bank PWS - PWS # 00193 dated April 22, 1999.

Freeze, R. Allan and Cherry, John A., 1979. Groundwater, Prentice-Hall, Inc.

Heath, , R. C, 1984, Ground-Water Regions of the United States, U.S. Geological Survey Water Supply Paper 2242, p. 78.

Montana Department of Environmental Quality, Permitting & Compliance Division and the Drinking Water Assistance Program - Montana Water Center: Ground Water Manual for Small Water Systems, January 1999.

Montana Bureau of Mines and Geology tabular well information, 2003: http://mbmgsun.mtech.edu/ & http://mbmggwic.mtech.edu/

Montana State Library - Natural Resource Information Service, 2000. Graphical and tabular information: http://nris.state.mt.us/mapper/

Montana State Library - Natural Resources Information System (NRIS) 2000 map base of the USGS Topographical coverage at 1:24,000 scale in MrSID format.

U. S. Environmental Protection Agency (US EPA), 1991. Manual of Small Public Water Supply Systems, US EPA Office of Water (WH-550), EPA 570/9-91-003.

U.S. Geological Survey, 2000. National Landcover Dataset, Montana. 30-meter electronic digital landcover / land use data set interpreted from satellite imagery.

U.S. Geological Survey, 2002. Real-time streamflow and water quality information: http://mt.waterdata.usgs.gov/nwis/rt

Western Regional Climate Center, 2002. Climate Summary Data by City: http://www.wrcc.dri.edu/summary/climsmmt.html Zimmerman, E. A., 1967, Water Resources of the Cut Bank Area, Glacier and Toole Counties, Montanan, Montana Bureau of Mines and Geology Bulliten 60, p37.

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GLOSSARY*

Acute Health Effect. An adverse health effect in which symptoms develop rapidly.

Alkalinity. The capacity of water to neutralize acids.

Best Management Practices (BMPs). Methods that have been determined to be the most effective, practical means of preventing or reducing pollution from nonpoint sources.

Coliform Bacteria. Bacteria found in the intestinal tracts of animals. Their presence in water is an indicator of pollution and possible contamination by pathogens.

Confined Aquifer. A fully saturated aquifer overlain by a confining unit such as a clay layer. The static water level in a well in a confined aquifer is at an elevation that is equal to or higher than the base of the overlying confining unit.

Confining Unit. A geologic formation that inhibits the flow of water.

Delineation. A process of mapping source water management areas.

Effective Porosity. The percent of soil, sediment, or rock through which fluids, such as air or water, can pass. Effective porosity is always less than total porosity because fluids can not pass through all openings.

Hardness. Characteristic of water caused by presence of various salts. Hard water may interfere with some industrial processes and prevent soap from lathering.

Hazard. A measure of the potential of a contaminant leaked from a facility to reach a public water supply source. Proximity or density of significant potential contaminant sources determines hazard.

Hydraulic Conductivity. A coefficient of proportionality describing the rate at which water can move through an aquifer.

Inventory Region. A source water management area that encompasses an area expected to contribute water to a public water supply well within a fixed distance or a specified groundwater time-of-travel distance.

Maximum Contaminant Level (MCL). Maximum concentration of a substance in water that is permitted to be delivered to the users of a public water supply. Set by EPA under authority of the Safe Drinking Water Act.

Nitrate. An important plant nutrient and type of inorganic fertilizer. In water the major sources of nitrates are septic tanks, feed lots and fertilizers.

Nonpoint-Source Pollution. Pollution sources that are diffuse and do not have a single point of origin or are not introduced into a receiving stream from a specific outlet.

Pathogens. A bacterial organism or virus typically found in the intestinal tracts of mammals, capable of producing disease.

Point-Source. A stationary location or fixed facility from which pollutants are discharged.

Porosity. The percent of soil, sediment, or rock filled by air, water, or other fluid.

Public Water Supply (PWS). A system that provides piped water for human consumption to at least 15 service connections or regularly serves 25 individuals.

SIC Code. The U.S. Standard Industrial Classification (SIC) Codes classify categories of businesses. SIC Codes cover the entire range of business categories that exist within the economy.

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Source Water Protection Area. For surface water sources, the land and surface drainage network that contributes water to a stream or reservoir used by a public water supply.

Susceptibility (of a PWS). The potential for a PWS to draw water contaminated at concentrations that would pose concern. Susceptibility is evaluated at the point immediately preceding treatment or, if no treatment is provided, at the entry point to the distribution system.

Synthetic Organic Compounds (SOC). Man made organic chemical compounds (e.g. pesticides).

Total Dissolved Solids (TDS). The dissolved solids collected after a sample of a known volume of water is passed through a very fine mesh filter.

Total Maximum Daily Load (TMDL). The total pollutant load to a surface water body from point, non-point, and natural sources. The TMDL program was established by section 303(d) of the Clean Water Act to help states implement water quality standards.

Turbidity. The cloudy appearance of water caused by the presence of suspended matter.

Transmissivity. The ability of an aquifer to transmit water.

Unconfined Aquifer. An aquifer containing water that is not under pressure. The water table is the top surface of an unconfined aquifer.

Volatile Organic Compounds (VOC). Any organic compound which evaporates readily to the atmosphere (e.g. fuels and solvents).

Recharge Region / Watershed. The land area that drains into a stream; the watershed for a major river may encompass a number of smaller watersheds that ultimately combine at a common delivery point.

* Definitions taken from EPA’s Glossary of Selected Terms and Abbreviations and other sources.

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FIGURES

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Figure 1: General Location Map

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FIGURE 2: Climate Summary Graph – Imbedded in text on page 3.

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Figure 3: Spill Response Region Map With Other Pubic Water Supplies In The Area

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Figure 4: General Geologic Map

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FIGURE 5: Daily flow for Cut Bank Creek at Cut Bank – Imbedded in text on page 6.

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FIGURE 6: Peak Flow Levels for the Cut Bank Creek at Cut Bank – Imbedded in text on page 6.

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Figure 7: Spill Response Region and Landcover/Landuse Map

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Figure 8: Watershed Region Inventory Map

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Figure 9: Cut Bank PWS Watershed Region Landcover/Landuse Map.

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APPENDICES

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APPENDIX A - Listing of Potential Contaminant Sources by SIC Code and Supplemental List Provided by PWS Operator

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APPENDIX B - DEQ PWS’s Database Output

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Inorganic Water Quality Sampling Results – Cut Bank PWS

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Bacteriological Sampling Data - Cut Bank PWS

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APPENDIX C - Sanitary Survey

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APPENDIX D - Concurrence Letter & Other Correspondence

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