Table 1

PCE concentrations (ug/L) measured in water samples according to characteristics of sampling location and methods

No. of Samples
 No. With NDa Level
 Percent With NDa Level
 Meanb
 Median
 75th Percentile
 Range
All Samples
 88
 43
 49
 66
 0.5
 32
 ND-2432








According to:






Complexity of pipe configurationc






     Simple
 31
 13
 42
 73
 20
 50
 ND-780
     Complex
 57
 30
 53
 63
 ND
 22
 ND-2432
Magnitude of flowc






     High (> 19 homes)
 19
 11
 58
 10
 ND
 20
 ND-59
     Medium (3–19 homes)
 33
 22
 67
 18
 ND
 20
 ND-190
     Low (< = 2 homes)
 36
 10
 28
 141
 18
 57
 ND-2432
Position along pipec






     End
 44
 16
 36
 56
 12
 37
 ND-780
     Beginning/Middle
 44
 27
 61
 77
 ND
 25
 ND-2432
Overestimated housing densityc






     Yes
 25
 11
 44
 182
 6.6
 38
 ND-2432
     No
 63
 32
 51
 20
 ND
 28
 ND-235
Season sampledc






     Spring
 74
 42
 57
 77
 ND
 38
 ND-2432
     Autumn
 14
 1
 7
 7.7
 4.6
 11
 ND-44
Water fixture sampledc






     Tap or spigot
 10
 3
 30
 302
 32
 190
 ND-2432
     Hydrant
 18
 7
 39
 26
 21
 35
 ND-92
     Unknown
 60
 33
 55
 39
 ND
 18
 ND-780
Sampling personnelc






     Sampler 1
 69
 33
 48
 38
 0.5
 31
 ND-780
     Sampler 2
 18
 10
 56
 43
 ND
 28
 ND-350
     Sampler 3
 1
 0
 0
 2432
 ---d
 ---d
 ---d
Townc






     Barnstable
 7
 7
 100
 ND
 ND
 ND
 ND-ND
     Bourne
 16
 10
 63
 57
 ND
 26
 ND-540
     Brewster
 7
 2
 29
 140
 32
 100
 ND-780
     Chatham
 6
 5
 83
 4.9
 ND
 ND
 ND-28
     Falmouth
 6
 1
 17
 47
 53
 62
 ND-75
     Provincetown
 5
 5
 100
 ND
 ND
 ND
 ND-ND
     Sandwich
 9
 3
 33
 36
 22
 59
 ND-92
     Plymouth
 25
 7
 28
 128
 3.1
 13
 ND-2432
     Wareham
 7
 3
 43
 15
 20
 28
 ND-35
Pipe installation yearc






     1968–1972
 23
 16
 70
 38
 ND
 1
 ND-780
     1973–1976
 32
 15
 47
 18
 4.6
 25
 ND-100
     1977–1980
 33
 12
 36
 134
 22
 59
 ND-2432

a ND – Not Detected. The detection limit was 0.5 μg/L.

b Means were calculated using 0.25 μg/L (half the detection limit) for ND samples.

c See text for definitions and further description.

d Analyses were not conducted.

Spence et al. Environmental Health 2008 7:24   doi:10.1186/1476-069X-7-24