• Highway Right-of-Way Sludge Disposal

      Tilsworth, T.; Manning, D. (1986-05)
      This report encompasses a proposal to consider application of wastewater sludge to highway right-of-way. Conventional disposal of this sludge is a complex and expensive process and in some areas is severely restricted by land use and regulations. The report includes a literature review, a national survey of highway organizations and a hypothetical design analysis. Application of sludge to highway ROW can be beneficial by supplying nutrients required for plant growth, subsequent erosion stabilization and ultimate disposal of a waste resource. Disadvantages include negative public reaction, potential for contamination of ground and surface water, aesthetics, and relatively high costs. Preliminary findings of the report indicate the process is marginally feasible and recommends that a small pilot project should be conducted prior to full-scale consideration
    • Nutrient chemistry of a large, deep lake in subarctic Alaska

      LaPerriere, J. D.; Tilsworth, T.; Casper, L. A. (University of Alaska, Institute of Water Resources, 1977-08)
      The primary objective of this project was to assess the state of the water quality of Harding Lake, and to attempt to predict the effects of future development within its watershed. Since the major effect of degradation of water quality due to human activity is the promotion of nuisance growths of plants, the major emphasis was placed on measurements of plant growth and concentrations of the major nutrients they require. Planktonic algal growth was found to be low, below 95.6 gm/m2/year, and the growth of submerged rooted plants was found to be relatively less important at approximately 1.35 gm/m2/year. Measurements of the growth of attached algae were not conducted, therefore the relative importance of their growth is currently unknown. A model for predicting the effect of future real estate development in the watershed was modified and applied to this lake. This model adequately describes current water quality conditions, and is assumed to have some predictive ability, but several cautions concerning application of this model to Harding Lake are discussed. A secondary objective was to study the thermal regime of a deep subarctic lake. Intensive water temperature measurements were made throughout one year and less intensive measurements were conducted during two additional years. The possibility that this lake may occasionally stratify thermally under the ice and not mix completely in the spring was discovered. The implications of this possibility are discussed for management of subarctic lakes. Hydrologic and energy budgets of this lake are attempted; the annual heat budget is estimated at 1.96 x 104 ± 1.7 x 103 cal/cm2. The results of a study of domestic water supply and waste disposal alternatives in the watershed, and the potential for enteric bacterial contamination of the lake water are presented. Limited work on the zooplankton, fishes, and benthic macroinvertebrates of this lake is also presented.