Table 2 Correlation coefficients between measured PCE concentrations in water samples and model-generated estimates

All Samples

88

0.48

< 0.001

According to:

Complexity of pipe configuration^a

   Simple

31

0.51

0.003

   Complex

57

0.38

0.003

Magnitude of flow^a

   High (> 19 homes)

19

0.37

0.1

   Medium (3–19 homes)

33

0.30

0.09

   Low (< = 2 homes)

36

0.54

0.0007

Position along pipe^a

   End

44

0.44

0.003

   Beginning/Middle

44

0.44

0.003

Overestimated housing density^a

   Yes

25

0.52

0.008

   No

63

0.47

0.0001

Season sampled^a

   Spring

74

0.50

< 0.0001

   Autumn

14

0.58

0.03

Water fixture sampled^a

   Tap or spigot

10

0.84

0.002

   Hydrant

18

0.34

0.2

   Unknown

60

0.38

0.003

Sampling personnel^a

   Sampler 1

69

0.45

0.0001

   Sampler 2

18

0.57

0.01

   Sampler 3

1

---^b

---^b

Town^a

   Barnstable

7

---^c

---^c

   Bourne

16

0.53

0.03

   Brewster

7

0.018

1.0

   Chatham

6

0.39

0.4

   Falmouth

6

0.49

0.3

   Provincetown

5

---^c

---^c

   Sandwich

9

0.53

0.1

   Plymouth

25

0.56

0.003

   Wareham

7

0.48

0.3

Pipe installation year^a

   1968–1972

23

0.42

0.05

   1973–1976

32

0.56

0.0008

   1977–1980

33

0.37

0.03