Plaintiffs’ hydrogeology expert, Dr. Donald Siegel, mapped the area where PFAS from the MassNatural site has reached groundwater and private wells. The proposed classes in this case are defined by that area and by the list of properties in his report.
Figure 2 from Dr. Siegel’s report (Dkt. No. 577-1). Outline colors show the highest PFAS6 level measured on each property, in parts per trillion. The dashed line marks the plume boundary. Select the map to enlarge it.
What the testing shows
Massachusetts limits PFAS6 in drinking water to 20 parts per trillion. Dr. Siegel found levels around the MassNatural site well above that limit, in some places by many hundreds of times.
PFAS6 has been detected on at least 282 residential properties, and 195 of those homes now have treatment systems.
MassDEP identified 69 homes for connection to Fitchburg’s public water system because their well tests exceeded its 90 parts per trillion “imminent hazard” level. As of July 2026, 8 of those homes had been connected.
Sources: report of Dr. Donald Siegel (Dkt. No. 577-1) and report of Dr. Robert Simons (Dkt. No. 577-4), which cites MassDEP and the site’s environmental consultant.
Properties in the plume
Appendix 3 of Dr. Siegel’s report lists 479 properties in Westminster and Fitchburg that lie within the plume, in whole or in part. It identifies each property by the map and lot number the town assessor uses, which appears on your property tax bill.
474 map and lot numbers listed.
13 / 1
13 / 2
13 / 3
13 / 5
14 / 5
14 / 9
14 / 10
14 / 11
15 / 1
15 / 2
15 / 3
15 / 4
15 / 5
15 / 6
15 / 7
16 / 1
16 / 2
16 / 3
16 / 4
16 / 5
16 / 5 / 1
16 / 5 / 2
16 / 5 / 3
16 / 5 / 4
16 / 5 / 5
16 / 5 / 6
16 / 5 / 16
16 / 5 / 17
16 / 5 / 18
16 / 5 / 19
16 / 5 / 20
16 / 5 / 21
16 / 6
16 / 7
16 / 8
16 / 9
16 / 10
16 / 11
16 / 11 / 1
16 / 11 / 2
16 / 11 / 3
16 / 11 / 4
16 / 11 / 5
16 / 11 / 6
16 / 11 / 7
16 / 11 / 8
26 / 1
27 / 2
27 / 2 / 1
27 / 2 / 2
27 / 2 / 3
27 / 2 / 5
27 / 2 / 41
27 / 2 / 42
27 / 3
27 / 4
27 / 5
27 / 6
27 / 7
27 / 8
27 / 9
28 / 1
28 / 2
28 / 3
28 / 4
28 / 5
28 / 6
28 / 7
28 / 8
28 / 9
28 / 10
28 / 11
28 / 12
28 / 13
28 / 14
28 / 15
28 / 16
28 / 17
28 / 18
28 / 19
28 / 20
29 / 1
29 / 2
29 / 3
29 / 3 / 1
29 / 3 / 2
29 / 3 / 3
29 / 3 / 4
29 / 3 / 5
29 / 3 / 6
29 / 3 / 6 / A
29 / 3 / 7
29 / 3 / 8
29 / 3 / 9
29 / 3 / 10
29 / 3 / 11
29 / 3 / 12
29 / 3 / 13
29 / 3 / 14
29 / 3 / 15
29 / 3 / A
29 / 4
29 / 5
30 / 1
30 / 2
30 / 5
30 / 6
31 / 1
41 / 1
41 / 2
41 / 3
41 / 4
41 / 5
41 / 6
41 / 7
41 / 8
41 / 9
41 / 10
41 / 12
41 / 12 / 1
41 / 12 / 2
41 / 12 / 3
41 / 12 / 4
41 / 13
41 / 14
41 / 14 / 1
41 / 14 / 2
41 / 14 / 3
41 / 14 / 4
41 / 14 / 5
41 / 14 / 6
41 / 14 / 7
41 / 14 / 8
41 / 14 / 9
41 / 15
42 / 1
42 / 2
42 / 3
42 / 4
42 / 5
42 / 6
42 / 7
42 / 8
42 / 9
42 / 10
43 / 1
44 / 1
44 / 2
44 / 3
44 / 4
44 / 5
44 / 11
44 / 11 / 1
44 / 11 / 2
44 / 11 / 3
44 / 11 / 4
44 / 11 / 5
44 / 11 / 6
44 / 11 / 7
44 / 11 / 8
44 / 11 / 9
44 / 11 / 10
44 / 11 / 11
44 / 11 / 12
44 / 11 / 13
44 / 11 / 14
44 / 11 / 15
44 / 11 / 16
44 / 11 / 17
44 / 11 / 18
44 / 11 / 22
44 / 11 / 23
44 / 11 / 24
44 / 11 / 25
44 / 11 / 26
44 / 11 / 27
44 / 11 / 28
44 / 11 / 29
44 / 11 / 30
44 / 11 / 31
44 / 11 / 32
44 / 11 / 33
44 / 11 / 34
44 / 11 / 35
44 / 11 / 36
44 / 11 / 37
44 / 11 / 38
44 / 11 / 39
44 / 11 / 40
44 / 11 / 41
44 / 11 / 42
44 / 11 / A
44 / 13
44 / 14
44 / 15
44 / 16
44 / 17
44 / 17 / 1
44 / 18
44 / 19
44 / 20
44 / 21
46 / 2
46 / 3
46 / 4
46 / 6
46 / 8
46 / 9
46 / 9 / 1
46 / 10
46 / 11
46 / 12
46 / 13
46 / 13 / 1
46 / 14
46 / 15
46 / 16
46 / 17
46 / 17 / 1
46 / 18
46 / 19
46 / 20
46 / 21
46 / 22
54 / 1
54 / 2
54 / 3
54 / 4
54 / 5
54 / 6
54 / 7
54 / 8
54 / 9
54 / 10
54 / 11
54 / 12
54 / 13
54 / 14
54 / 15
54 / 16
54 / 17
54 / 18
54 / 19
54 / 20
54 / 24
54 / 24 / 1 / B
54 / 24 / 1 / D
55 / 1
55 / 2
55 / 3
55 / 4
55 / 5
55 / 6
55 / 7
55 / 8
55 / 8 / 1
55 / 9
55 / 10
55 / 11
55 / 12
55 / 13
55 / 14
55 / 15
55 / 17
55 / 18
55 / 19
55 / 21
55 / 22
55 / 23
55 / 24 / 1
55 / 24 / 1 / A
55 / 24 / 2
55 / 25
55 / 25 / 1
56 / 1
56 / 2
57 / 1
57 / 2
58 / 1
58 / 2
59 / 1
59 / 2
59 / 3
59 / 4
59 / 5
59 / 6
59 / 7
59 / 8
59 / 9
59 / 10
59 / 11
59 / 12
59 / 12 / 1
59 / 12 / 2
59 / 12 / 3
59 / 12 / 4
59 / 12 / 5
59 / 12 / 6
59 / 12 / 7
59 / 12 / 8
59 / 12 / 9
59 / 12 / 21
59 / 13
59 / 14
59 / 15
59 / 16
59 / 17
59 / 18
59 / 19
59 / 20
59 / 21
59 / 22
59 / 23
59 / 24
59 / 25
59 / 26
59 / 27
59 / 28
59 / 29
59 / 30
59 / 31
59 / 32
59 / 33
59 / 34
60 / 1
60 / 1 / 1
60 / 2
60 / 3
60 / 4
60 / 5
60 / 6
60 / 7
60 / 8
60 / 9
60 / 10
60 / 11
60 / 12
60 / 15
60 / 16
60 / 17
60 / 18
60 / 19
60 / 21
60 / 22
60 / 22 / 1
60 / 22 / 2
60 / 22 / 3
60 / 22E
73 / 1
73 / 2
73 / 3
73 / 4
73 / 5
73 / 6
73 / 7
73 / 8
73 / 9
73 / 10
73 / 10 / 1
73 / 10 / 2
73 / 10 / 3
73 / 10 / 4
73 / 10 / 5
73 / 10 / 6
73 / 10 / 7
73 / 10 / 8
73 / 10 / 9
73 / 10 / 10
73 / 11
73 / 12
73 / 13
73 / 14
73 / 16
73 / 17
73 / 18
73 / 19
73 / 20
73 / 21
73 / 22
73 / 23
73 / 23 / 1
73 / 23 / 2
73 / 23 / 3
73 / 23 / 4
73 / 23 / 5
73 / 23 / 6
73 / 23 / 7
73 / 23 / 16
73 / 23 / 17
73 / 23 / 18
73 / 23 / 19
73 / 24
73 / 25
73 / 26 / 7
73 / 26 / 8
73 / 26 / 9
73 / 26 / 10
73 / 26 / 11
73 / 26 / 12
73 / 26 / 13
73 / 26 / 14
73 / 26 / 15
73 / 26D
73 / 27
73 / 28
73 / 29
73 / 30
73 / 31
73 / 32
73 / 33
74 / 1
74 / 2
74 / 3
74 / 4
74 / 5
75 / 1
75 / 2
75 / 3
75 / 3 / 1
75 / 3 / 2
75 / 4
75 / 5
75 / 6
75 / 7
75 / 8
76 / 20
76 / 21
76 / 22
76 / 23
76 / 25
76 / 26
76 / 27
76 / 28
110R / 2 / 0
110R / 3 / 0
110R / 4 / 0
110R / 10 / 0
110R / 16 / 0
241 / 11 / 0
241 / 11 / 2
241 / 11 / 3
241 / 11 / 4
241 / 11 / 5
241 / 11 / 6
241 / 11 / 7
241 / 11 / 8
241 / 11 / 9
241 / 11 / 10
241 / 11 / 11
241 / 11 / 12
241 / 11 / 13
241 / 11 / 14
241 / 11 / 15
241 / 11 / 16
241 / 11 / 17
241 / 11 / 18
241 / 11 / 19
241 / 11 / 20
241 / 11 / 21
241 / 11 / 22
241 / 11 / 23
241 / 11 / 24
241 / 11 / 25
241 / 11 / 26
246 / 11 / 1
246 / 11 / B
S7 / 18 / 0
S7 / 29 / 0
S32 / 7 / 0
S32 / 7 / A
S32 / 9 / 0
S32 / 14 / A
S32 / 18 / 0
W / 11 / 0
Five properties on the list have no map and lot number. Some listed properties are only partly within the plume, and Plaintiffs may add to or change the list as testing continues.
Who the proposed classes include, using this list
Property Damage Class: anyone who owned a listed property at any time on or after January 31, 2022.
POET Subclass: owners of a listed property where a MassDEP-approved consultant measured PFAS6 above 20 parts per trillion and a treatment system has been installed and maintained.
Medical Monitoring Class: anyone who has lived at a listed property since 1987 and drank its PFAS6-contaminated well water, and children born to them while they met these criteria.
The Court has not certified any class. If your property is not on the list but is near the plume, or you are not sure, contact us.
