Soil was incubated in the presence of Prudhoe Bay crude oil at 20 deg C under shake-flask conditions. With the addition of N and P to the medium, the susceptibility of aromatic compounds to microbial degradation over an 11-day period was found to be: naphthalene approx. = 2-methylnaphthalene 1-methylnaphthalene dimethylnaphthalenes approx. = dibenzothiophene approx. = phenanthrene C(,3)-napthalenes methyl-phenanthrenes C(,2)-phenanthrenes. The n-alkanes and isoprenoids (pristane and phytane) were also extensively degraded during this time. The omission of N and P from the medium reduced the extent to which the culture degraded the n-alkanes but had little effect on the degradation of the aromatic fraction after a 27-day incubation period.

Visakhapatnam Basin, located on the east coast of India adjoining the Bay of Bengal, is surrounded by hills. Groundwater in the basin is utilized for domestic, irrigational, and industrial purposes. The basin measures about 148 km('2) in which 35% of the land is utilized for irrigation, and 10% of the land for industries. However there is a rapid industrial development in the basin along with increasing population initiating the necessity to evaluate groundwater resources. The chemical quality of groundwaters available in the basin is discussed in relation to domestic, irrigational, and industrial purposes.

The effect of 50, 100, 150, and 400 mu-g sodium pentachlorophenate (Na-PCP) per gram soil was studied in nonsterile soil incubated under aerobic and anerobic conditions, and in sterilized soil inoculated with Azotobacter sp. isolated from the soil. N(,2) fixation was determined by acetylene reduction. Pentachlorophenate at a concentration of 50 mu-g/g had an inhibitory effect in nonsterile soil incubated aerobically while strong inhibition of dinitrogen fixation in nonsterile soil occurred in the presence of 100 mu-g/g and above. The EC(,50) values for the inhibition of nitrogenase activity in nonsterile soil incubated aerobically and anaerobically and in sterlilized soil inoculated with Azotobacter sp. suspensions were 49.8 +/- 1.4 mu-g Na-PCP/g, 186.8 +/- 2.8 mu-g Na-PCP/g, and 660.8 +/- 29.3 mu-g Na-PCP/g, respectively.