SOURCE WATER DELINEATION & ASSESSMENT REPORT Franklin Hills Subdivision PWS DEQ PWS ID# MT0004734

Contact Persons: August Uhl 406/ 600-1320 Operator: Eric Campbell 406/ 581-8662 Owner: Franklin Hills Subdivision c/o Brian Lee 406/ 582-8775

Franklin Hills Subdivision c/o August Uhl 82 Franklin Hills Drive Bozeman, Montana 59715

PREPARED BY: Jeffrey Frank Herrick Montana Department of Environmental Quality Source Water Protection Program

Dated: March 2012

Table of Contents

Introduction ...... 4 Purpose ...... 4 Public Water Supply ...... 4 Table 1. Franklin Hills Subdivision PWS ...... 5 Table 2. Well Log Information ...... 5 Delineation ...... 6 Geology & Groundwater ...... 6 Inventory ...... 7 Fuel Storage Tanks ...... 7 Septic Systems ...... 7 Cultivated Cropland ...... 8 Susceptibility Assessment ...... 8 Table 3. Susceptibility Assessment ...... 9 References ...... 11 Attachments ...... 12 Photographs ...... 13 Note: The above photographs were taken during DEQ’s 2010 Sanitary Survey...... 15 Figures ...... 17 Figure 1: Location Map ...... 17 Figure 2: Subdivision / Site Map ...... 17 Figure 3: Geologic Map ...... 17 Figure 4: Area Wells ...... 17 Figure 5: Inventory Region, Potential Point Contaminant Sources Map ...... 17 Figure 6: Inventory Region, Potential Non-Point Contaminant Point Sources Map ...... 17 Figure 7: Inventory Region, Potential Non-Point Contaminant Point Sources Map ...... 17 Supplemental Documentation ...... 19

INTRODUCTION

This delineation and assessment report (SWDAR) 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). Jeffrey Frank Herrick with Montana DEQ’s Source Water Protection Program assembled the needed information and wrote the Source Water Delineation and Assessment Report (SWDAR) for this public water supply. Information on land use and potential contaminant sources comes from a variety of sources including a preliminary land cover data layer produced by the United States Geological Survey (USGS), DEQ Public Water Supply files, other public sources of information, and field observations. A web-based GIS application was also used to query and generate maps to support the writing of this report. Purpose The purpose of this SWDAR (Source Water Delineation and Assessment Report) is to assess threats to the Franklin Hills Subdivision public water supply using information obtained from site visits, local residents familiar with the area and published reports. Delineation is a process whereby areas that contribute water to aquifers or surface waters used for drinking water are identified on a map. These areas are referred to as source water protection areas. Assessment involves identifying locations or regions in source water protection areas where contaminants may be generated, stored, or transported and then determining the potential for contamination of drinking water by these sources. Public Water Supply The Franklin Hills Subdivision is located off of Bozeman Trail Road, approximately 1 mile east of the City of Bozeman, just south of Highway I-90. The subdivision is located as depicted on Figure 1 and Figure 2 (in the Attachments). Note the subdivision boundaries depicted on Figure 2. The public water system that serves the subdivision consists of 2 wells, a large pressure tank, no common header, and the distribution system. Well #1 / WL002 and Well #2 are found in the central portion of the subdivision on the north and south of the tank house. No common header is present and each of the wells supplies water and pressure independently to the distribution system. The water system is classified by Montana DEQ as a Community Non-Transient as there are 17 residential service connections providing water to approximately ~43 residents. A tabular summary of the PWS facilities in found on Table 1 and a summary of the PWS wells is on Table 2 (below).

Table 1. Franklin Hills Subdivision PWS DEQ PWS ID # MT0004734 Community Non-Transient Total Population: 43 residents Service Connections: 17 RS connections DEQ Facilities List Location Facility Name DEQ ID Latitude Longitude Well #1 WL002 45.6652 -110.9986 Well #1 Sample Pt EP502 Well #2 WL003 45.6645 -110.9982 Well #2 Sample Pt EP503 Pressure Tank PC001 45.6647 -110.9982 211 Gallons, in tank house Common Header CH001 Does not exist Distribution DS001 Throughout subdivision Distr. Sample Pt SP001

Table 2. Well Log Information Well 1 ( WL002 ) Site Name on Log Franklin Hills Subdivision Well #1 GWIC ID 155309 DNRC Water Right 96720 Owner Name c/o Shroyer, Kevin Location See Table 1, above Completion Date 13 September 1995 Driller Haggerty Drilling Lic. WWC-353 Boreholes 0-25 feet: 9 inch 25-157 feet: 6 inch Casings -2-157 feet: 6 inch steel, welded 147-157 feet: 6 inch, 0.04 slotted screen Well Seal 0-25 feet bgs Neat Cement Total Depth 160 feet bgs Static Water Level 51 feet bgs Pumped at 60 gpm w/ drawdown to 146 feet bgs

Well 2 ( WL003 ) Site Name on Log Franklin Hills Subdivision Well #2 GWIC ID 155374 DNRC Water Right Owner Name c/o Shroyer, Kevin Location See Table 1, above Completion Date 18 September 1995 Driller Haggerty Drilling Lic. WWC-353 Boreholes 0-25 feet: 9 inch 25-159 feet: 6 inch Casings -2-159 fee: 6 inch steel, welded 149-159 feet: 6 inch, 0.04 slotted screen Well Seal 0-25 feet bgs Neat Cement Total Depth 160 feet bgs Static Water Level 62 feet bgs Pumped at 30 gpm w/ drawdown to 141 feet bgs

Note: The above information was drawn from the MBMG GWIC well logs.

The public water supply wells for Franklin Hills Subdivision are identified as Well #1 and Well #2. These well locations are depicted on Figure 1 and Figure 2. These wells are detailed in the table above and the well logs are found in the Attachments at the end of this report. Note that well logs for select area wells are also found in the Attachments at the end of this report. The locations of the area wells with well logs in the Attachments are depicted on Figure 4. The Franklin Hills Subdivision PWS wells are located in the central park/open space in the center of the subdivision, with the tank house located between the 2 wells. The tank house contains 2 (two) H2O PRO model H2PL82 captive air tanks and 1 (one) Signature SR-85-25-01 captive air tank. The well logs for the PWS wells indicate that the lithology of the aquifer consists of clay, gravel, and cemented gravel with clay layers. The lithologic logs for other area wells indicate that the entire neighborhood is underlain by similar extensive clay beds, claybound gravel and sand, silty sandstone, cemented sand and gravel, and complex bedded clay/sand & gravel/cemented claybound gravel. For the purpose of this assessment, the aquifer tapped by the Franklin Hills Subdivision and all of the surrounding wells is interpreted to be unconfined to semi- confined. The presence of scattered clay or silt bed rich deposits may or may not act to protect the well from contamination originating at the surface. The aquifer beneath this site is assigned a moderate sensitivity rating to potential contaminant sources at the surface, in accordance with the Source Water Protection Guideline document (MT DEQ,1999).

The Franklin Hills Subdivision water system is classified as a Community Non-Transient PWS and is required to test for microbiological pathogens as well as a suite of organic and inorganic contaminants (including nitrates). The water system has only recently been recognized and regulated by DEQ as a public water supply, so its sampling history only goes back to 11/2010. From 2010 until the writing of this report, the water supply has had no samples testing positive for Coliform bacteria. During this same period none of the other contaminants were present in concentrations anywhere near their EPA mandated maximum concentration limits (MCLs). The nitrate concentration in samples from Well #1 were 1.02 mg/L and from Well #2 were 1.03 mg/L, both of which are below the EPA’s MCL of 10 mg/L. This low nitrate concentration in the well water samples probably represents a background concentration in the aquifer beneath the subdivision. A printout of DEQ’s PWS database summarizing the PWS’s facilities, water quality history, and regulatory history is found in the Attachments at the end of this report.

DELINEATION

Three source water protection zones are delineated for the Franklin Hills Subdivision Public Water Supply wells. These areas include a 100-foot radius Control Zone surrounding the 2 wells as depicted on the inset to Figure 2. A one-mile radius Inventory Region was modified to remove much of the downgradient area and is depicted on Figure 5 and Figure 6. In addition, a Recharge Region that encompasses the watershed above the PWS is found on Figure 7. The other figures found in this document support these delineations. The Control Zone is the most critical area from which direct introduction of contaminants into the well or immediate area can occur. The Inventory Region encompasses the area from which water or contaminants can reach a groundwater intake (the PWS well) over a period of months to years. The size of the Inventory Region can be based on aquifer characteristics or a conservative 1-mile fixed radius around the PWS well(s). Geology & Groundwater Based upon the well logs and geologic summaries for the area, the subsurface characteristics beneath this area are generally described as moderately well-cemented Tertiary age fanglomerate that was derived from the nearby mountains (USGS 1996). Refer to Figure 3 for a map of the distribution of local surfical geologic deposits. Local deposits appear consist of sediment that was stream deposited conglomerate (poorly sorted & chaotic) dropped directly onto alluvial fans flanking the mountain range front (south of the fans). The alluvial fans are thick, complexly interfingered and/or layered, chaotic sediments that were deposited at a time when the local streams or rivers had very low flow volumes and did not carry sediment out of the Gallatin Valley. This is a time when there was insufficient rainfall to maintain streams or rivers that flowed between major valleys. As such, the fans are rich in locally derived clay, silt, and sand & gravel that are bound up in the finer materials (thus the common description seen in the local well logs “claybound gravel and sand”). The local deposits appear to be Tertiary age, which was prior to the wetter climate seen during the later Pleistocene’s glacial period. These sediments are also old enough to have been somewhat cemented or lithified. The geologic map on Figure 3 of this report describes the local deposits around and beneath the Franklin Hills Subdivision as “Sediment or sedimentary rock, upper Tertiary, coarse- grained (Tsuc)”. The 1996 USGS report suggested that there is up to 150 feet of the older alluvium of Tertiary (and possibly Pleistocene) age that mantles even older Tertiary pediments along the Gallatin Range front.

The compilation of well logs for area wells as seen in the Attachments are arranged from north to south. Well depths of area wells are predominantly between 90-170 feet deep with static water levels that ranged mostly from 30-70 feet below ground surface (bgs). These well depths are consistent with the “less than 150 feet” thickness of the Tertiary fan deposits described above. The shallower water levels were found in the north and deeper water levels were in the south. In spite of the clay rich deposits, most of these wells yielded 15-25 gallons/minute, which may have come from water bearing units within the fan that were somewhat interconnected or from some sand or gravel deposits located beneath the clay rich fan materials. Groundwater in the alluvial aquifer beneath this area is interpreted to flow from the south to the north-northwest, generally towards and then sub-parallel to the East Gallatin River (Slagle 1995). A map of local wells is found on Figure 4.

INVENTORY

The Montana Source Water Protection Program (MT DEQ, 1999) requires that land uses and all potential sources of contamination within the Control Zone and Inventory Region be identified. Figure 5 and Figure 6 have an aerial photo background showing the subdivision, nearby properties, and the modified 1-mile Inventory Region. Figure 5 depicts potential point sources of contamination identified within the Inventory Region. Figure 6 depicts potential non-point sources of contamination within the Inventory Region.

The inset for Figure 2 depicts the Control Zones for the PWS wells. Although the Franklin Hills Subdivision is on individual septic disposal systems, it does not appear that there are any septic system features or other potential contaminant sources located within 100 feet of either of the wells. The PWS managers should verify that there are no septic tanks or drainfields within the Control Zones. The wells are located within an open area that appears to have a lawn. Care should be taken to minimize the application of fertilizers or other chemicals in the vicinity of the wells.

Figure 7 depicts the Recharge Region for this PWS, which is in effect the watershed above the PWS that provides water to the aquifer used by the PWS. There were a few UST sites located in the watershed, but no other significant potential contaminant sources were present that would affect long term water quality.

Fuel Storage Tanks Figure 5 depicts a number of fuel storage tank sites within the Inventory Region. One of the sites is a leaking underground fuel storage site (LUST site) identified as the Rodney Hobaugh site and is located north of the subdivision. The extent of subsurface contamination at this LUST site is unknown. This LUST site is down-gradient from the PWS and is outside the Inventory Region. The remainder of the fuel tank sites are where underground fuel storage tank sites (UST sites) are located south and east of the subdivision. None of these sites are known to have active or historic fuel releases (spills or leaks).

Septic Systems Figure 6 depicts potential non-point sources of contamination in and around the Inventory Region. Based on aerial imagery and other available data, the land surrounding and directly to the south of the Franklin Hills Subdivision has a medium density of private onsite septic systems. There are a couple of neighborhoods (one to the north and one to the east) that have a high septic density. These areas of increased septic density are considered potential sources of nitrates and pathogens. Figure 5 depicts potential point sources of contamination within the Inventory Region. Among these is a public water supply (Building Blocks Academy), which also operates large capacity septic system. It is located to the southeast of the subdivision. Due to the volume of septic effluent processed by a large septic system, they are considered a significant potential contaminant source.

Cultivated Cropland Along with septic density, Figure 6 depicts areas of cultivated cropland and pasture/hay production land. These agricultural land uses can be a significant source of nitrates and some pesticides or herbicides. This is especially true if these lands are nearby and irrigated. Within the Inventory Region there is a large area of cultivated cropland directly west of the subdivision. There are areas of pasture/hay and cultivated cropland found in the southern portion of the Inventory Region south of Kagy Road/Bozeman Trail Road. Although it isn’t clear from the aerial photos, it appears that little of this land is intensely irrigated.

SUSCEPTIBILITY ASSESSMENT

Susceptibility to potential contaminant sources is assessed for a public water supply well. The Franklin Hills Subdivision PWS wells have been constructed to MT DEQ Public Water Supply standards. The 2 wells were sealed to a depth of 25 feet with cement and well logs were completed (see Attachments). When a well is properly sealed, shallow ground water is less vulnerable to contaminant sources at the ground surface. The aquifer beneath this site is considered unconfined to semi-confined and is assigned a moderate sensitivity to potential contaminant sources located at the surface. The cross- or down-gradient location of some of the potential contaminant sources is used as a barrier that stands between the contaminant source and the PWS source well intakes. The hazard and susceptibility ratings for each potential contaminant source as well as management options are summarized in Table 3. Identified potential sources of contamination within the Inventory Region include: Areas of increased septic density; A large capacity septic system; Cultivated cropland; And Buried fuel storage tanks (UST sites).

It does not appear that there are any septic systems within the Control Zones for the PWS wells. There are areas of increased septic density within the Inventory Region. Within the Inventory Region there’s a high density of septic systems directly south of I-90 and north and east of the subdivision. There are areas of medium septic density located surrounding, east, and south of the subdivision. Most of the region has a low septic density. Due to the proximity of areas of increased septic density, a high hazard to this PCS is assigned. A number of barriers are thought to be in-place between the increased septic density areas and the PWS wells. As such, the PWS wells are thought to have a moderate susceptibility. See Table 3 below. A single large capacity septic system was identified up- gradient from the PWS wells. It is assigned a high hazard, but there are believed to be barriers in place. The PWS wells are thought to have a moderate hazard to this PCS.

Underground fuel storage tanks (UST sites) are found within the Inventory Region. Because of their proximity, they’re assigned a high hazard. A number of barriers were identified with these sites, which means that the PWS wells will probably have a moderate susceptibility to contamination associated with these sites. See Table 3 below.

The non-irrigated agricultural lands in the area probably represent a low hazard. The irrigated cropland in the Inventory Region (as seen in the color aerial photograph) probably occupies less than 20% of the area, and is assigned a low hazard. There appear to be several barriers between the agricultural related contaminants and the PWS wells, which yields a very low susceptibility. See Table 3 below.

. Table 3. Susceptibility Assessment

(For significant potential contaminant sources in the Control Zone and Inventory Region)

Source Contaminant Hazard Hazard Barriers Susceptibility Management Rating

Onsite Large Pathogens and Leaks, Effluent High This septic system is located ~3,000 feet away from the subdivision’s wells. Moderate Consider resident education on proper use & Capacity Septic Nitrate discharge that Clay lenses and some thick near surface clay units present in the maintenance of septic disposal system. may be sedimentary strata beneath the site. System (for the inadequately Surface drainage ditch stands between the PCS and the subdivision’s Building Blocks treated wells. Academy) Static water levels are >50 feet bgs. Well intakes are ~100 feet below static water level.

Septic Density Pathogens and Leaks, Effluent High Clay lenses and some thick near surface clay units present in the Moderate Promote management of the density of septic (areas of nitrate discharge that sedimentary strata beneath the site. systems through zoning or septic permitting as increased septic may be Surface drainage ditch stands between the PCS and the subdivision’s possible. density) inadequately wells. Prioritize the connection of increased septic treated Static water levels are >50 feet bgs. density areas to public or more centralized Well intakes are ~100 feet below static water level. (community) septic treatment systems. This would need to be coordinated through city utilities, city and county commissioners, and the Local Water Quality Protection District. Consider public info and education on septic maintenance strategies to protect groundwater.

Buried Fuel Volatile organic Spills and High Clay lenses and some thick near surface clay units present in the Moderate Maintain and update spill response plan Tank Sites compounds and leaks from the sedimentary strata beneath the site. Ensure the drainage ditches actually capture ( UST Sites ) assorted tanks and fuel Surface drainage ditch stands between the PCS and the subdivision’s and can carry liquid contaminants away from petroleum lines. wells. the PWS well. hydrocarbons. Static water levels are >50 feet bgs. Well intakes are ~100 feet below static water level. Spill Response Planning by County Health Department, Extensive regulatory oversight by County and State of Montana. Cleanup management by State. Inventory control. Spill reporting. Secondary containment and leak alarm systems.

Table 3. Susceptibility Assessment

(For significant potential contaminant sources in the Control Zone and Inventory Region)

Source Contaminant Hazard Hazard Barriers Susceptibility Management Rating

Agricultural Pathogens and Non-point Low Clay lenses and some thick near surface clay units present in the Very Low Reinforce BMP education for community and Land Nitrate, Pesticides source (air photo of area sedimentary strata beneath the site. local neighbors. Use and Herbicides contamination, suggests that little Surface drainage ditch stands between the PCS and the subdivision’s Promote good neighbor policies to improve (irrigated land is (SOCs) contaminants of the cropped wells. awareness of the PWS and the need for less than 20% of leaching into agricultural land is Static water levels are >50 feet bgs. protective actions on the part of local the region. See ground water irrigated). This Well intakes are ~100 feet below static water level. landowners. Figure 6) should be revised Most of the cropped agricultural land is lateral to the groundwater flow, so it if this assumption is not up-gradient from the PWS wells. Some of this land is along the is not correct. southern-most portion of the region (along the southern boundary). As such, that distance from the PWS will promote diffusion or dilution of the chemical contaminants. In addition, you can probably count of some degree of natural attenuation of these contaminants prior to their reaching the area of the PWS. .

Note : The above susceptibility determination is for wells that withdraw water from an unconfined aquifer.

REFERENCES

DEQ (1999) Source Water Protection Program, Department Circular PWS 6 - Source Water Protection Delineation: Department of Environmental Quality, Helena, Montana

Hackett, O.M., F.N. Visher, R.G. McMurtney, and W.L. Steinhilber (1960). Geology and Ground-Water Resources of the Gallatin Valley, Gallatin County, Montana: US Geological Survey Water Supply Paper 1482.

Kendy, E. (2001, Magnitude extent, and potential sources of nitrate in ground water in the Gallatin Local Water Quality District, Southwestern Montana, 1997-1998: US Geological Survey Water-Resources Investigations Report 01-4037, Helena, Montana.

Montana Bureau of Mines and Geology, 2011. Ground water Information Center, lithologic well logs, http://mbmggwic.mtech.edu

Montana Department of Environmental Quality, Public Water Supply Section, 2005, Safe Drinking Water Information System (SDWIS).

Montana Department of Environmental Quality (DEQ), 1999, Montana Source Water Protection Program, http://www.deq.state.mt.us/ppa/p2/swp/index.asp

Montana Department of Environmental Quality (DEQ), 2000, Montana Source Water Protection Program, Template for Non-Community, Transient Public Water Supplies, Revised 2002..

Montana Natural Resources Information Interactive Map website, 2005. http://nris.state.mt.us/interactive.html

Safe Drinking Water Act (SDWA) Amendments of 1996 [U.S. Code Title 42, Chapter 6A, Subchapter XII, Part E, §300J-13-(a) Source Water Assessment].

US Geologic Survey, 1996, Water-Resources Investigations Report 96-4025, Geographic, Geologic, and Hydrogeologic Summaries of Intermountain Basins of the Northern Rocky Mountains, Montana. Kendy, E. and Tresch R.E.

ATTACHMENTS

Photographs

Franklin Hills Subdivision PWS – SWDAR 2012 Page 15 of 36

Franklin Hills Subdivision PWS – SWDAR 2012 Page 16 of 36

Note: The above photographs were taken during DEQ’s 2010 Sanitary Survey.

Franklin Hills Subdivision PWS – SWDAR 2012 Page 17 of 36

Figures

Figure 1: Location Map

Figure 2: Subdivision / Site Map

Figure 3: Geologic Map

Figure 4: Area Wells

Figure 5: Inventory Region, Potential Point Contaminant Sources Map

Figure 6: Inventory Region, Potential Non-Point Contaminant Point Sources Map

Figure 7: Inventory Region, Potential Non-Point Contaminant Point Sources Map

Supplemental Documentation