Watersheds We Help Protect
Watersheds We Help Protect > Northeast > Clear Spring
Clear Spring, Maine
Clear Spring is located in Hollis, Maine, within the watersheds of Killick Pond and Wales Pond Brook, which flow into the Saco River. The area that comprises the watershed is approximately 7,670 acres in size. This area is made up of steeply sided valleys carved by streams and rivers into plains formed of sand, gravel and clay deposited by melting glaciers after the last ice age. The major surface water features that dominate the landscape are the Saco River, Killick Pond and its associated streams, and Wales Pond Brook and its wetlands and ponds.
QUICK FACTS*
Conserved Acres: 1,200
Total Acres: 1,588
2023 Withdrawals (Mgal): 219.7
% of Annual Watershed Precipitation: 2.4%
Water Stress: Very Low
Figure 1: Maine’s Water Cycle
Rain and snow that fall in the watershed recharge the aquifer and groundwater resource throughout most of the year. This natural cycle of water occurs throughout Maine and includes precipitation, runoff infiltration to groundwater and evaporation/transpiration. (Figure 1)
DEFINITION OF A SPRING
A spring is the location where groundwater (water that exists beneath the earth’s surface) naturally emerges from the ground. BlueTriton withdraws mostly spring water in Hollis. The withdrawal locations - or “boreholes” - intercept Clear Spring water before it naturally emerges from the ground. There are six spring water boreholes in Hollis.
WATER WITHDRAWALS AND SUSTAINABILITY
In Maine, the Department of Environmental Protection (DEP) regulates spring water withdrawal through the issuance of permits. In addition to an extensive scientific investigation of the site, the DEP required that BlueTriton construct, calibrate and verify a comprehensive groundwater flow model before issuing a permit. This model and its findings were used by the DEP to set a potential extraction volume from Clear Spring sources of up to 237.7 million gallons (MG) of water per year.
While this may seem like a large number, it is important to remember that annually 9.8 billion gallons (BG) or 52 inches of water fall on the Hollis watershed in the form of precipitation (based on a 29-year average). Therefore, the amount of BlueTriton’s water withdrawal permit represents less than 2.4% of the entire volume of water received in the watershed area annually.
Other withdrawals by BlueTriton in Hollis include utility water withdrawals of up to 47 MG per year for purified water production, plant sanitary requirements, fire protection and industrial uses.1
SITE MONITORING
Independent scientists contracted by BlueTriton regularly monitor the groundwater system, springs, wetlands, homeowner water supplies, and surface water bodies. To comply with state permits, BlueTriton monitors extraction rates at all boreholes and utility wells and continuously monitors stream flow at three stations in the watershed. Additionally, water levels in a network of nearby homeowner water supply wells are monitored on a daily basis via data loggers deployed in these wells. These considerable monitoring efforts ensure that BlueTriton’s operations do not adversely affect the groundwater, surface water, natural environments, or neighbors. The independent scientists submit monthly monitoring data and annual report to the Town of Hollis and the DEP. This summary document condenses the most recent annual report submission, which can be viewed at Town Hall.
RECENT MONITORING RESULTS
The graphs below summarize important measures of the health of the natural groundwater and surface water systems. The first graph (Figure 2) depicts water levels at Monitoring Wells 6 and 9, which are monitoring wells centrally located in the aquifer used by BlueTriton. For comparison, water levels from U.S. Geological Survey (USGS) well (background well) in Sanford, Maine along with monthly precipitation are also presented. This USGS well is located outside of the Clear Spring Aquifer. The water levels in the Clear Spring Aquifer naturally fluctuate by a few feet, depending on the season and the amount of precipitation. Spring and fall rains typically lead to aquifer recharge, while growth and uptake of water by plants in the summer decrease aquifer water levels, as does the lack of recharge during winter months when the ground is frozen. Inspection of the graphs indicate that fluctuations of precipitation each year correlates with trends of groundwater levels measured at on-site monitoring wells (Monitoring Wells 6 and 9). Similar trends are also observed in the USGS background monitoring well (Figure 2). Years of monitoring data have shown that BlueTriton’s activities have not resulted in adverse impacts on these natural cycles.
Figure 2: Groundwater Monitoring Data
Surface water bodies respond similarly to these natural cycles, as shown in the second graph (Figure 3). Melting snow and spring rains lead to increased surface water flows. Hotter, drier summer weather, combined with uptake of moisture by plants, reduces available surface water flow. The DEP has set minimum pass-by flow requirements that BlueTriton must meet. Past flows below these requirements have been the result of fluctuations in precipitation, beaver dam construction and clogging of upstream dam grates by falling leaves and debris. When these occur, BlueTriton reports the incidents to the DEP and works cooperatively with the DEP to address issues as they arise.
Figure 3: Surface Water Monitoring Data
FUTURE MONITORING
BlueTriton takes its environmental stewardship responsibilities seriously and is committed to sustainable management of natural resources. Monitoring the groundwater, surface water, habitat and precipitation in Hollis will continue for as long as BlueTriton withdraws spring and utility water here.
SUMMARY
Water withdrawals by BlueTriton at Clear Spring in Hollis are regulated by the DEP and managed sustainably through proactive monitoring and responsible use. Water withdrawal activity has not resulted in adverse impacts to homeowner water supplies, groundwater, surface water, wetlands, or other natural resources.
RESOURCES & INFORMATION
BlueTriton is committed to increasing the transparency of our operations and water stewardship practices through our Reading Room.
Questions about Clear Spring or the information contained in this summary can be directed to:
Water withdrawals at Clear Spring are regulated by:
• Town of Hollis
• Maine Dept. of Environmental Protection
• Maine Dept. of Health & Human Services
(Maine Drinking Water Program)
*Footnotes:
The percent withdrawal is derived by taking the annual withdrawal divided by the total rainfall within the watershed that year. A watershed is an area of land and its streams and rivers that drain to a single body of water, such as a larger river, a lake or the ocean.
