The study was conducted to appraise the trophic status of the saline Onondaga Lake, Onondaga County, New York, and to estimate the effects of the proposed waste treatment plant. The determined parameters included circulation patterns, distribution of chemical constituents, and the biotic contents of the lake. Mineral-water equilibria showed an uninterrupted and a widely distributed formation of phosphate-bearing minerals. The predominant component of lake sediments is calcium. The salinity of lake water did not preclude occurrence of a wide variety of phytoplankton, zooplankton, and fish. Proposed waste treatments should significantly increase the supply of dissolved oxygen and lower the phosphorus concentration.

Periodic taste and odor at the Cleveland, Ohio Crown Water Treatment Plant prompted investigation of the role microorganisms play in the problem. Fungi, bacteria, and algae collected near the plant intake were studied during June through August 1971. During the three months of sampling, no vertical distribution pattern was noted in quantitative analysis of the phytoplankton. A number of algae, reported to induce taste and odor in water, were identified. Whatever the source of these odors, they were not due to benthic or periphyton algae, but could have been associated with the phytoplankton community as the reported 'Lake Erie odor' coincided with phytoplankton increase.

The water impounded at Indian Creek Reservoir near Lake Tahoe, California is approximately one-third surface runoff and direct precipitation and two-thirds reclaimed water exported from South Tahoe Public Utility District Plant. Discussed are the results of tests which determined the temporal changes and relationships between water quality characteristics of Indian Creek Reservoir and those of the reclaimed water. Initially the reservoir would not support fish life, but as the reservoir matured, ammonia levels declined to less than 4 mg/l and by 1970 it was an excellent trout fishery. Approximately 70% of the ammonia nitrogen was lost to the atmosphere by nitrification-denitrification. Good biological productivity indicated access to other phosphorus sources, probably runoff. Relative to conductivity and chemical components the water is of good irrigation quality. Various parameters showed that the reservoir responds to more complex factors than those measurable in the reclaimed waste water, raising the question of the effectiveness of tertiary treatment for recreational impoundments.

Instantaneous amounts of organic carbon, both particulate and dissolved, in a number of freshwaters ranging from unproductive tarns to moderately productive reservoirs were measured by acid-persulfate digestion and infrared absorption. Organic carbon was designated as net seston carbon, filter seston carbon, or dissolved carbon based on filtering techniques. Repeated sampling showed amounts of organic carbon, either dissolved or particulate, fluctuated considerably over short periods of time; the dissolved fraction probably varying less than particulate forms. Almost daily measurements in samples incubated over three week periods also revealed erratic changes, with no clear reduction in total organic carbon. The data have descriptive value, although they cannot, at this time, be related satisfactorily to the general limnological knowledge.