TABLE 1.

Comparison of volume capacities between the HV and standard Envirochek filters^a

Sample site	Turbidity (NTU)	Vol filtered (liters) (mean ± SE)b
		HV filter	Standard filter
Campbell Lake	88	3.2 ± 0.19 A	1.7 ± 0.32 B
Hood	99	7.0	4.0
Bethany	11	10	10
Barker Slough	36	10	NAc
Barker Slough	47	5.0	NA

^aThree replicate samples were compared.

^bValues followed by the same letter are not significantly different (t test, P = 0.008). Standard error could not be calculated for filter capacity comparisons in matrix spike experiments.

^cNA, not analyzed.