196 HUMMON et al. 



values. Subtracting carbonate from total conductivity and applying 

 the faunal v^^eighting factors (which show, incidentally, that only at 

 Sandy Run and Long Run were the majority of animals in the upper 

 layer of sediment) gives the numerator values (Table 2, column A) 

 of the preliminary physical— chemical index. 



Dissolved oxygen treated as decimal saturation showed the 

 expected constancy in stream water (x= 0.97, SD = 0.08, n = 14) 

 but a wide variability in interstitial water (x=0.51, SD = 0.24, 

 n = 14) (Table 2). Application of faunal weighting factors resulted in 

 one of two parts (Table 2, column B) of the index's denominator. 

 The BOD showed wide variability both in stream water (x=2.8, 

 SD = 1.1, n = 14) and in interstitial water (x= 3.2, SD = 1.8, n = 14). 

 Little pattern was visible from the standpoint of faunal weighting 

 factors or faunal abundance. 



Stream flow showed more than a 100-fold difference between 

 sites, though no site carried a large volume of water (Table 2). 

 Minkers Run had the largest flow, more than doubling its volume 

 between the upper and lower sites; Tick Ridge had the smallest flow. 

 Raccoon Creek showed the largest difference in flow between sites, 

 and, relative to the amount of flow, Long Run and Sandy Run 

 showed the least. Taking the cube root of flow rate resulted in the 

 second part (Table 2, column C) of the index's denominator. Light 

 transmission in stream waters was high at the time of most 

 collections; this indicated stable conditions and a lack of erosional 

 runoff due to rainfall. Only Minkers Run (upper site, 60%; lower site, 

 77%) showed less than 100% transmission. 



Iron ranged from trace amounts at Tick Ridge, Strouds Run, 

 and Margaret Creek to 2.2 ±0.5 ppm at Raccoon Creek; manganese 

 ranged from trace amounts at Strouds Run to 19.6 ±2.1 ppm at 

 Raccoon Creek; and sulfate ranged from 72 ± 7 ppm at Tick Ridge, 

 Strouds Run, and Margaret Creek to 1055 ± 375 ppm at Raccoon 

 Creek (Table 2). Calcium and total hardness were lowest at Tick 

 Ridge (51 ± 7 and 85 ± 7 ppm) and highest at Raccoon Creek 

 (327 ± 46 and 650 ± 57 ppm). Little pattern was noted among the 

 streams having intermediate values. Only at Raccoon Creek was there 

 a consistent relationship between stream and interstitial waters with 

 respect to these five chemical parameters, the values of interstitial 

 waters being 0.67 ± 0.08 times those observed in stream waters. 



The compensated noncarbonate conductivity, A/(B x C), values 

 for each site are shown in Table 3 in decreasing order of magnitude 

 together with the faunistic data with which they were correlated. 

 The number of taxa encountered, ranging from 3 at Raccoon Creek 



