CAMP KOOCH-I-CHING SOURCE WATER ASSESSMENT

Transcription

1 CAMP KOOCH-I-CHING SOURCE WATER ASSESSMENT PWS ID Facility Contact: Minnesota Department of Health Contact: Mr. Jerry Bergvall Ms. Beth Kluthe Camp Kooch-I-Ching Minnesota Department of Health P.O. Box Bemidji Avenue International Falls, Minnesota Bemidji, Minnesota Telephone Number: (218) Telephone Number: (218) PART I INTRODUCTION The 1996 Amendments to the federal Safe Drinking Water Act require the Minnesota Department of Health (MDH) to complete source water assessments for public water supply systems. Protecting the drinking water source (Rainy Lake) is a wise and relatively inexpensive investment in the future. Source water assessments are intended to inform consumers of: 1) the area which contributes water to Camp Kooch-I-Ching, 2) a listing of the contaminants of concern and the sources of those contaminants, and 3) a determination of the susceptibility of the public water supply system to potential contamination. This source water assessment was prepared with the assistance of a team representing: the operator and owner, Koochiching County water planning, citizen volunteers, and MDH engineering and planning staff. -1-

2 STATUS OF A SOURCE WATER PROTECTION PLAN Public water supply systems that use surface waters are not required to prepare source water protection plans, but this source water assessment provides the basis for a locally developed source water protection plan. The MDH is strongly encouraging the development of voluntary source water protection plans by public water supply systems. Camp Kooch-I-Ching has expressed interest in developing a source water protection plan. DESCRIPTION OF THE SOURCE WATER The water supply for Camp Kooch-I-Ching is obtained from Rainy Lake. Rainy Lake is located on the United States/Canadian border in Koochiching and St. Louis Counties in Voyageur s National Park. The lake has a total surface area of 220,800 acres, a maximum depth of 161 feet, and is located in the Northern Lakes and Forests Ecoregion of the Rainy River Basin. Based on Carlson s Trophic Status Index (TSI) (Carlson 1977), Rainy Lake would be considered oligotrophic to mesotrophic. An oligotrophic lake is a relatively nutrient-poor lake and is clear and deep with bottom waters high in dissolved oxygen. Black Bay is a large shallow embayment located towards the western end of the lake and is considered eutrophic with the highest level of nutrient and algal productivity on the lake. Sulfide concentrations in Black Bay exceed the U.S. Environmental Protection Agency criteria for protection of aquatic life. The Rat Root River drains a large wetland complex to the south of the lake and drains to Black Bay. Water quality data from the Minnesota Pollution Control Agency s data base indicate that Rainy Lake has a higher TSI value than 86 percent of all other lakes in the ecoregion. The Namakan Reservoir supplies water to Rainy Lake at three sources: Squirrel and Kettle Falls at the northwest end of Namakan Lake, Bear River on the north-central side of Namakan Lake, and Gold Portage which drains into Black Bay from the west end of Kabetogama Lake. The major outlet is the Rainy River to the west. The Northern Lakes and Forest Ecoregion is characterized by forests with water and wetlands. The land-use pattern for this area of the state is typically 75 percent forested, 5 percent cultivated, 11 percent wetland and water, 7 percent pasture and open, and 2 percent developed. The water treatment system consists of prechlorination, Kinetico back-washing media bed filters for pretreatment, followed by a bag filter as the final filter/protozoa barrier. Storage tanks provide contact time with chlorine to allow adequate disinfection. SOURCE WATER SENSITIVITY Sensitivity is defined as the likelihood that surface waters will be isolated from contaminants by the natural abilities of a source water and the surrounding environment to attenuate or retard the movement of contaminants to the intake of a public water supply. -2-

3 The size, depth, and flow of Rainy Lake will help attenuate the movement of contaminants to the intake. The dam located at Kettle Falls does influence the flushing rate of the lake. Other factors influencing the sensitivity of a surface-water body include topography, hydrology, geology, vegetation, and the distribution of various soil types. The immediate sub-watershed of Rainy Lake can be described as having shallow soils on bedrock; topography is dominantly rolling with irregular slopes and many craggy outcrops of bedrock; vegetative cover is primarily forested. Black Bay contributes significant organic staining. SOURCE WATER ASSESSMENT AREAS The source water assessment areas for Camp Kooch-I-Ching include three distinct nested areas. The smallest area is termed the emergency response area (Figure 1) and is designed to help Camp Kooch-I-Ching address contaminant releases which present an immediate (acute) health concern to water users. This geographic area is defined by a 200-foot radius from the shore/intake intersection. The intermediately-sized area is termed the source water protection management area (Figure 2) and is designed to protect water users from the long-term (chronic) effects related to low levels of chemical contamination or the periodic presence of contaminants at low levels. Also, this area should protect users from contaminants such as pathogens which may be usually present at treatable levels in the source water but occasionally present an acute health concern under certain conditions. The source water protection management area boundary is defined by five factors: intake length, intake depth, lake classification, lake residence time, and lake substrate under the intake. The Camp Kooch-I-Ching public water supply system has a medium sensitivity rating based on these five factors. This means the boundary of this area is a 1,000-foot radius from the intersection of the shoreline and intake pipe. The largest area is termed the entire watershed (Figure 3) and is designed to provide the water supplier with a broad perspective of the types of land uses that may impact the water quality of the source water used by them. The Rainy Lake sub-watershed and Rat Root River subwatershed are included in this area. -3-

4 FIGURE 1 EMERGENCY RESPONSE AREA -4-

5 FIGURE 2 SOURCE WATER PROTECTION MANAGEMENT AREA -5-

6 FIGURE 3 ENTIRE WATERSHED -6-

7 PART II POTENTIAL CONTAMINANTS OF CONCERN The contaminants of concern are the 83 contaminants regulated under the federal Safe Drinking Water Act. They are divided into organic chemicals, inorganic chemicals, radionuclides, and microorganisms. A listing can be found at: Of greatest concern are microorganisms. POTENTIAL SOURCES OF CONTAMINANTS The table below is an estimate of the types and number of potential contaminant sources located in the emergency response area, the source water protection management area, and the entire watershed. The data was gathered from a variety of sources including: local source water advisory team, field inventories, and state data bases. TYPE OF SOURCE EMERGENCY AREA MANAGEMENT AREA ENTIRE WATERSHED Sewage Systems NA Unknown 550 Sewage Lift Station 2 Unknown NA Unregulated Under-Ground Storage Tanks Unregulated Above- Ground Storage Tanks 0 0 Unknown 0 1 Unknown Regulated Tanks Gas Pumps Marina Dump EPA Hazardous Waste Handler Superfund Site Solid Waste Facility

8 Other potential sources of contamination include: municipal and industrial wastewater discharges and bypasses, runoff, shoreline modification, wetland alteration, stream channelization, dam operation, wildlife, logging activities, spills/shipping, river influences, beaver activity, and petroleum storage. The table below lists the type of land use and cover in the entire watershed and estimates the percentages per use. LAND USE ACRES PERCENT Not Classified Open Water Low Intensity Residential High Intensity Residential Commercial/Industrial/Transportation Quarries/Strip Mines/Gravel Pits Barren Transitional Deciduous Forest Evergreen Forest Mixed Forest Shrubland Pasture/Hay Row Crops Urban/Recreational Grasses Woody Wetlands Emergent Herbaceous Wetlands TOTAL Land use and cover data were obtained from the National Land Cover Data and a more detailed explanation can be found at: RESULTS OF MONITORING THE SOURCE WATER Source water monitoring efforts are conducted by the National Park Service. A water quality investigation was conducted on Rainy Lake and Black Bay from Future water quality monitoring efforts will focus on an assessment of effects of changes in reservoir operations. -8-

9 SUSCEPTIBILITY OF THE SOURCE WATER TO CONTAMINATION The overall susceptibility of any surface-water source is determined to be high because there are no practical means of preventing all potential contaminant releases into surface waters. However, a susceptibility determination for a specific public water supply system is based on comparing the sensitivity of the surface-water intake to the presence of a source which may release a contaminant of concern. This secondary analysis allows for differentiation between surface-water based public water supply systems. The sensitivity of the source water for the Camp Kooch-I-Ching is considered to be low based on the size, flow, and depth of the lake and surrounding shorelands, which are primarily forested with development limited to low density residential and commercial recreational development along the south shore of the lake. Water quality testing results for Rainy Lake indicate the lake overall has high water quality. There are relatively few potential contaminant sources located in close proximity to the surface-water intake. Based on a comparison of the sensitivity of the surface-water intake to the presence of potential contaminant sources, the susceptibility of the Camp Kooch-I-Ching is considered to be low for a surface-water based public water supply system. -9-