Kim's Marina and Resort Public Water System

KIM’S MARINA AND RESORT PUBLIC WATER SYSTEM

PWSID# MT0002857

SOURCE WATER DELINEATION AND ASSESSMENT REPORT

Report Date: 9/4/03

Contact Person:

Gregory Axtman Kim’s Marina and Resort 8015 Canyon Ferry Road Helena, MT 59601

Phone: (406) 475-3723

DRAFT

TABLE OF CONTENTS

Section Page Number

Introduction 1 Purpose 1 Limitations 1 Water Supply Information 1 Geography 2 Geology 3 Water Quality 3 Delineation 4 Inventory 4 Susceptibility Assessment 5 Summary 6

References 7

Appendices 8

Appendix A: Area Well Logs Appendix B: Site Layout

Figures

Figure 1: Kim’s Marina and Resort Vicinity Map Figure 2: Kim’s Marina and Resort Well Location Map Figure 3: Kim’s Marina and Resort Regional Geology Figure 4: Kim’s Marina and Resort Inventory Region Figure 5: Kim’s Marina and Resort Regional Land Use Figure 6: Kim’s Marina and Resort Regional Septic Density

Source Water Delineation and Assessment Report for Kim’s Marina and Resort, PWS# MT0002857

Introduction

Carolyn DeMartino, a Water Quality Specialist with the Montana Department of Environmental Quality (DEQ), and Amy C. Schlatter, DEQ Intern completed the Kim’s Marina and Resort Source Water Delineation and Assessment Report.

Purpose

The Source Water Delineation and Assessment Report (SWDAR) for the Kim’s Marina and Resort (Kim’s) Public Water System (PWS) is intended to meet the technical requirements of 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 protecting public drinking water supplies from contamination. A major component of the program is “delineation and assessment”. Delineation is a process of mapping source water protection areas, which contribute water used for drinking. Assessment involves identifying locations or regions in source water protection areas where contaminants may be generated, stored, or transported, and then determining the relative potential for contamination of drinking water by these sources.

Limitations

The terms “drinking water supply” or “drinking water source” refer specifically to the source of Kim’s public water supply and not to any other public or private water supply. Also, not every potential or existing source of groundwater or surface water contamination in the area has been identified. Identification of potential contaminant sources is limited to those regulated for this class of PWS and is generally based on readily available information and reports. Every effort has been made to ensure completeness, however, unregulated activities and unreported contaminant releases may have been overlooked.

The delineation method utilizes simplifying assumptions that may not fully represent complex ground water flow systems but is intended to be conservative and protective of public health.

Public Water Supply Information

The Kim’s PWS is located on the north east corner of Canyon Ferry Lake, just 1.4 miles east of Canyon Ferry Dam on Canyon Ferry Road (Figure 1) The legal location is SW1/4NW1/4, Section 2, T10N, R1W (Figure 2). This PWS utilizes two groundwater wells, Well #1 (WL002) and Well #2 (WL003), to supply water to the marina,

campgrounds, RV’s and surrounding services. Kim’s PWS serves a transient population of 300 people in the summer. An estimated water demand of 3000 gallons per day was determined using the water usage value of 10 gallons per day per transient person (EPA, 1991). There are no well logs or water right records for either well at the Department of Natural Resources and Conservation (DNRC) or the Montana Bureau of Mines and Geology (MBMG) and Ground Water Information Center (GWIC).

Information concerning well construction for both wells is based on a sanitary survey completed in 2001 by the Cadmus Group. Well #1, built in 1960, is located in a pump house in a lawn area between the store and the campground (Figure 2). The well is 67 feet deep, has a 6-inch casing, and a 1.5 horsepower submersible pump. Two pressure tanks control the cycling of the pump and provide and estimated 170 gallons of storage. The yield of the well in gallons per minute is unknown. Well #1 has run dry in past years when Canyon Ferry Lake levels receded to abnormal lows. Well #2 was completed to supplement Well #1 and to be used as a backup system when lake levels are low (Cadmus, 2001).

Well #2, built in 1995, is located in a pump house situated on a hill to the north-west side of the resort (Figure 2). The well is 90 feet deep and has a 8-inch casing and 1.75 horsepower pump. Three pressure tanks control the cycling of the well pump and provide an estimated 288 gallons of storage. The yield of Well #2 is also unknown (Cadmus, 2001).

Based on lithologic information obtained from other area well logs (Appendix A) it appears that wells #1 and #2 are most likely completed in unconfined Quaternary alluvium. Based on this aquifer type, the source water sensitivity to potential contaminant sources would be high.

Geography

Kim’s Marina and Resort is located on the northeast side of Canyon Ferry Lake in the mouth of Cave Bay which is located approximately 20 miles east of Helena. Canyon Ferry Lake was created when Canyon Ferry Dam was constructed on the Missouri River near the small settlement of Canyon Ferry. The Big Belt Mountains bound the Missouri River Valley to the northeast and the Spokane Hills bound the valley on the southwest side. Prominent river-cut terraces are present at several levels (Mertie, Fischer, and Hobbs, 1951).

Climate in the Canyon Ferry Lake area is considered semi-arid. The average monthly high and low temperatures in the vicinity range from 84.0 F to 52.2 F in July and 31.3 F to 13.6 F in January. Precipitation averages 11.36 inches annually concentrated in the months May through September. Snowfall averages 5.0 inches annually (WRCC).

Geology

Sedimentary rocks in the Canyon Ferry Lake area are comprised of rocks that range in age from Precambrian to Recent (Figure 3). The Precambrian rocks are composed of limestone and shale of the Belt Series. Paleozoic-aged formations are comprised of quartzite, shale, and limestone, and range in age from youngest to oldest, Cambrian to Permian rocks. Tertiary lake deposits in the area are composed of volcanic debris. Pleistocene gravels occur as terrace deposits above the water level of the Missouri River. Recent-aged (Quaternary) river alluvium consisting of gravel, sand, and silt are found on the valley floor and along major tributaries flowing into Canyon Ferry Lake. Kim’s well is located in Quaternary alluvium along cave gulch (Figure 3). Igneous rocks consisting of monzonite and granite that intruded sedimentary deposits are most likely Tertiary- aged. Lava flows and basalt dikes were intruded during the Miocene epoch. Historically, some copper, gold, and platinum mining occurred in the Canyon Ferry Lake vicinity. Sapphires have also been mined in this vicinity. Most neighboring mines in the region have been abandoned. (Mertie, Fischer, and Hobbs, 1951).

Water Quality

The source of drinking water for Kim’s PWS is groundwater. This PWS is classified as a transient non-community public water supply; therefore, the only regulated contaminants that are required to be routinely monitored in the drinking water include nitrate and microbial pathogens. In the last seven years, nitrate plus nitrite levels in the public water supply well range between 0.8 milligrams per liter (mg/L) to a high of 2.12 mg/L (DEQ SDWIS database). These levels are well below the EPA mandated maximum contaminant level of 10 mg/L (EPA, 2003).

Based on a review of the DEQ SDWIS drinking water database for this PWS, there have been four detections of coliform bacteria in the past five years. Coliforms are naturally occurring in the environment and are not a health threat in themselves. They are an indicator that harmful bacteria like fecal coliforms are present in the water. Fecal coliforms are bacteria that are associated with human or animal wastes. They usually live in human or animal intestinal tracts, and their presence in drinking water is a strong indication of recent sewage or animal waste contamination. These coliforms draw concern because they can include E. coli which is a serious threat to human health (EPA 2003).

It should be noted that other potential contaminant sources, for example underground fuel storage tanks, may impact the well if leaks or spills were to occur. Recent attention was brought to the possibility of contamination in Cave Gulch from use of mercury in upstream mining operations. The mercury was used to bond with gold as the gravel was washed through the sluice. The miners would then take these particles above ground and heat them, which would cause the mercury to vaporize and the gold to remain. The concern is that not all the mercury was removed from the underground tunnels, and has worked its way into the aquifer. Subsequent tests on regional well’s– “came back with undetectable levels of mercury, which means the water is perfectly acceptable for human

consumption” (Helena IR, 2002). Cave Gulch is susceptible to flash flooding, and this high volume of water could potentially displace any mercury, allowing it to flow down gradient and into the PWS.

Delineation

Groundwater in the vicinity of Kim’s Resort and Marina well’s appears to flow south to southwest toward Canyon Ferry Lake. A 100-foot fixed radius control zone and a one mile fixed radius inventory region were delineated around the well as required for a transient, non-community PWS under the Montana Source Water Protection Program (DEQ, 1999). The 100-foot radius control zone surrounding the well head is the most critical area which direct introduction of contaminants into the well or the immediate area can occur. The one-mile inventory region encompasses the areas that water or contaminants can flow to Well #1 and #2 over a period of months to years depending on flow velocity (Figure 4).

Inventory

The Montana Source Water Protection Program (DEQ, 1999) requires that land uses and all potential sources of nitrate and microbial pathogens be identified within the control zone and inventory region of transient, non-community public water systems. Note, that other potential contaminant sources, such as underground storage tanks may be located within the control zone and inventory region but are not considered as regulated potential contaminant sources because this is classified as a transient non-community PWS.

Land use within the 100 foot radius of Well #1 include a store, a pump house with two pressure tanks, and a gravel road (Appendix B). Land use within the 100-foot radius of Well #2 include a gravel road. Land use within the 1-mile radius inventory region around both wells includes grassland (45%), open water (23%), evergreen forest (21%), shrubland (9%), and transportation routes (Figure 5). These percentages are also shown on the pie chart in Figure 5. The marina and resort site layout is denoted in Appendix A. Septic density in the inventory region is generally low (96%) with localized areas of moderate (3%) and high levels (1%) (Figure 6). Cave Gulch has high septic density within the gulch grading into moderate and low nearer the lake. Kim’s location has low density but closely borders a region of moderate density (Figure 6).

Kim’s Marina and Resort is far from any town and may have an on-site, large capacity septic system, serving 20 or more people per day. The septic system is most likely located inside the inventory region and would therefore pose a possible threat to the public water system. The exact location of the septic system is unknown.

The most significant potential contaminant sources of nitrate and pathogens in the inventory region include the large capacity on-site septic system, and high density septic region up-gradient from the resort. Nitrates and pathogens could leach from the on-site septic system effluent into area groundwater. Contamination from the high density septic

system region could bring nitrates and microbes into the groundwater as it travels down- gradient to the lake.

Susceptibility Assessment

The proximity of a potential contaminant source to a well or the density of non-point potential contaminant sources determines the threat of contamination, referred to as hazard. The hazard rankings for the on-site septic system and regional septic density are based on the percentage of each within the inventory region. The hazard rankings of all potential significant contaminant sources identified within the Kim’s Marina and Resort region are presented in Table 1.

Table 1: Hazard Rankings of Significant Potential Contaminant Sources in the Kim’s Marina and Resort PWS Inventory Region.

Potential Contaminant Hazard Source Contaminants Description Rating Large Capacity On-site Nitrates and Pathogens Potential system failure, effluent High Septic System leaching to groundwater High Density of Septic Nitrates and Pathogens Potential system failure, High Systems (up-gradient) effluent leaching to groundwater

Hazard and the existence of barriers to prevent contamination determines the susceptibility of an aquifer to potential contamination. Barriers can be engineered, management actions, or natural. Examples of engineered barriers are spill containment structures for industrial facilities and leak detection for underground storage tanks. Examples of management barriers include the adoption of local ordinances to keep potential contaminant sources out of the control zone for wells, completion of a emergency response plan, or the use of best management practices to manage particular potential contaminant sources. Clay rich soils or a laterally continuous clay layer are examples of natural barriers.

Table 2 identifies the susceptibility ranking for each potential contaminant source in the inventory region and also includes management recommendations for these potential contaminant sources. If implemented, these management recommendations may be considered barriers. Also, as well logs are provided to the DEQ, this may help determine what barriers can be used in a reassessment of the susceptibility ranking.

Table 2: Susceptibility Assessment Ratings of Significant Potential Contaminant Sourcesin the Kim’s Marina and Resort PWS Inventory Region

Potential Hazard Source Contaminant Rating Barriers Susceptibility Recommendations Large Capacity Nitrates and High None Very High Conduct regular On-Site Septic Pathogens maintenance System High Density Nitrates and High None Very High Conduct regular Septic Systems Pathogens maintenance (up-gradient)

Summary

This report was prepared to assist the owner/operator of Kim’s Marina and Resort to better understand the public water system for which they are responsible. The report provides information concerning the aquifer that supplies water to the well and identifies the control zone and inventory regions. Within each of these protection areas the significant potential contaminants that may impact the well water are also identified. Also provided in the Table 2 are recommendations regarding how the potential source of nitrates and pathogenic contaminants could be managed to prevent impacts to Kim’s Marina and Resort wells.

References

Cadmus Group, Inc. Survey , October 2001, Sanitary survey of Kim’s Marina and Resort public water system (PWSID #02857). Completed by Maureen Donnelly.

EPA, 2003, Ground Water and Drinking Water, Consumer Fact sheet on Nitrates/Nitrites.

EPA, 1991, Office of Water, Manual of Small Public Water Supply Systems, EPA, 571/9-91-003, 221 p.

Independent Record, February 1, 2003, Mercury in water a concern, Helena.

Mertie, John B., Fischer, Richard P., and Hobbs, S. Warren, 1951, Geology of the Canyon Ferry Quadrangle, Montana, United States Geological Survey Bulletin 972.

Montana Department of Environmental Quality Public Water Supply Program Safe Drinking Water Information System (SDWIS).

Montana Bureau of Mines and Geology Ground Water Information Center (GWIC), Butte, Montana

Montana Department of Environmental Quality, 1999, Montana Source Water Protection Program, Approved by EPA in November, 1999.

Montana Department of Natural Resources and Conservation, Water Resources Division, Water Rights Bureau, Helena, Montana.

Montana Natural Resource Information System, Spatial Query and Mapping System (NRIS).

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

Western Regional Climate Center, [email protected], Montana Climate Summaries, Canyon Ferry Dam, Montana (241470). Period of Record : 12/28/1907 to 7/31/1996.

U.S. Geological Survey, 2000, National Land cover Dataset, Montana

APPENDIX A: Well Logs

And

APPENDIX B: Site Layout

Appendix B: Site Layout