All samples were collected from Beaver Lake in Ware, Massachusetts. Beaver Lake is located in western Massachusetts just south of the Quabbin Reservoir, which is one of the sources of drinking water for the City of Boston. Beaver Lake is an approximately 152-acre man-made lake that runs approximately 1.5 miles long flowing north to south. The lake is fed by Beaver Brook at the northern end and is designated for primary recreation. Beaver Lake is privately owned and managed by the Beaver Lake Trust. Land uses immediately surrounding the lake include undeveloped land, beaches, and residential properties. Residential properties are serviced by private drinking water wells and on-site wastewater disposal systems. Additionally, approximately eight stormwater conveyances drain runoff directly into Beaver Lake.
Ten sampling locations designated as Sites 1 through 16 (not continuous) were selected in an attempt to isolate different types of potential contaminant inputs. In particular, sampling locations were selected to target potential background locations, culvert discharges, and on-site wastewater disposal systems. Table 4-1 summarizes the sampling locations.
Sampling location designations start at Location 1 at the northern tip of Beaver Lake and progress clockwise around the lake to Location 16. Sampling locations 2, 3, 12, 13, 14, and 15 were originally considered, but were excluded from the sampling plan and never sampled due to access issues or redundancies. Figure 4-1 shows the sampling locations, and a brief description of each sampling site is included below. All site photographs were taken by Patrick Malone.
Table 4-1: Summary of Sampling Locations Sampling
Location Location Type/
Target Key Features
1 Background Beaver dam at lake influent
4 Septic Residence with leaching fields
5 Culvert Culvert immediately adjacent to Location 4 6 Culvert Sample directly from culvert discharge pipe 7 Culvert Culvert immediately downstream of Location 6 8 Septic Residence with leaching pits and steep slope 9 Culvert Culvert discharge to a lake cove
10 Septic Residence with leaching fields and steep slope 11 Background Man-made dam at lake effluent
16 Background Private beach
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Figure 4-1: Sampling Location Plan (createded using ESRI's ArcMap GIS by J. Tupper and adapted by P. Malone)
Site 1
Site 1 is located where Beaver Brook enters Beaver Lake at the northernmost point in the lake. Beaver Brook runs through a beaver dam prior to entering the lake. Site 1 is located just south and downstream of the beaver dam within Beaver Lake. Land abutting Site 1 is primarily undeveloped.
Site 4
Site 4 is located approximately 0.4 miles south of Site 1 on the eastern shore of Beaver Lake adjacent to the residence at 98 Shoreline Drive. The sampling location targets potential septic system influences. The residence has a 1,000 gallon septic tank with a 500 gallon leaching pit replaced in approximately 1992.
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Site 5
Site 5 is a culvert sampling location immediately south of Site 4.
Although the culvert pipe is not visible due to thick vegetation, water was observed discharging to Beaver Lake at this location during rain events. In addition, storm drains were identified on Shoreline Drive in the vicinity of Site 5.
Site 6
Site 6 is a culvert sampling location where the sample was collected directly from the discharge pipe only when water was flowing through it. During dry sampling events, this location was not sampled. Site 6 is located approximately 0.1 miles south of Site 5 on the eastern shore of the lake. Land uses abutting Site 6 include residential, a large paved drive, and undeveloped land associated with the stormwater drainage area.
Site 7
Site 7 is the lake water sample adjacent to Site 6. This sampling location is immediately downstream of the culvert at Site 6.
While Site 6 was only sampled when water is flowing through the culvert, Site 7 was sampled during both wet and dry sampling events.
Site 8
Site 8 is located approximately 0.25 miles south of Sites 6 and 7 on the eastern shore of Beaver Lake adjacent to the residence at 42 Shoreline Drive. The sampling location targets potential septic system influences, and there is a steep slope in the ground surface from the septic system to the lake. The residence has a 1,500-gallon septic tank with two 750-1,500-gallon leaching pits that were replaced/repaired in approximately 1996. Land surrounding Site 8 is generally residential.
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Site 9
Site 9 is a culvert sampling location located approximately 0.1 miles south of Site 8 on the eastern shore of Beaver Lake. The culvert discharge pipe was not identified; however, a stormwater drainage swale was observed between the suspected discharge area and the lake. The sample site was located in a fairly stagnant cove of Beaver Lake, and lake has a thick layer of leaf litter and organic matter at the sample location. Site 9 is abutted by residential land, a large paved drive, and undeveloped land associated with the stormwater drainage area.
Site 10
Site 10 is located approximately 0.15 miles south of Site 9 on the eastern shore of Beaver Lake adjacent to 4 Shoreline Drive. The sampling location targets potential septic system influences, and a steep slope in the ground surface leads from the septic system to the lake. The residence has a 1,500-gallon septic tank with three 33 feet by 3 feet infiltration trenches installed in approximately 2010. Land surrounding Site 10 is generally residential.
Site 11
Site 11 is located at the effluent of Beaver Lake at southernmost point in the lake. The sampling site is located within Beaver Lake just north and upstream of a man-made dam. Land abutting Site 11 includes a roadway, undeveloped land, and residences.
Site 16
Site 16 is located at a private beach on the western shore of Beaver Lake across the lake from Sites 6 and 7. Land abutting Site 16 is beach or undeveloped land.
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4.2 Sampling Dates
Samples were collected from January 2014 to February 2015 at a frequency of once every two to three weeks. The sampling schedule was designed to capture a full year of seasonal water quality data and to target dry and wet weather conditions. Table 4-2 summarizes the sampling schedule.
Seasons were defined using astronomical timing with spring starting on March 20, summer on June 21, fall on September 23, and winter on December 21 based on the equinoxes. As shown in Table 4-2, 21 sampling events were performed including 5 winter events, 4 spring events, 7 summer events, and 5 fall events. Additionally, measurable rainfall was recorded at the NOAA NCDC weather station at Westover Air Force Base in the 24 hours preceding sampling for eight of the sampling events with total antecedent rainfall measured between 0.04 and 1.55 inches.
Table 4-2: Summary of Sampling Dates
Sampling Date Season Rainfall 24 hours
preceding (in)
01/29/14 Winter 0
02/19/14 Winter 0
03/17/14 Winter 0
04/25/14 Spring 0
05/14/14 Spring 0
05/28/14 Spring 0.23
06/18/14 Spring 0.18
07/01/14 Summer 0
07/16/14 Summer 0.70
07/30/14 Summer 0
08/13/14 Summer 1.17
08/19/14 Summer 0
09/03/14 Summer 0
09/17/14 Summer 0.04
10/02/14 Fall 0.32
10/23/14 Fall 1.55
11/05/14 Fall 0
11/25/14 Fall 0.21
12/09/14 Fall 0
01/06/15 Winter 0
02/04/15 Winter 0