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retention dike for sanitary sewage for mal1Y years. The dike should be inspected to insure its integrity throughout its entire length. Any weakness discovered sliould be repaired. o Erosion protection. Inspection of the Uncompahgre River bank in the vicinity of the proposed fish pond indicates that some degree of bank erosion has been taking place. Protection of the fish pond from erosion by the Uncompaligre River is discussed ir, Section 11. o Maintenance, operation, and repair. An inspection and maintenance program for the fish pond should be preparec: and followed to minimi<\e major problems due to neglect, Naintenance of the desir~d species of fish should also be of concern. Division of Wildlife officials expressed concern about surreptitious seeding of unwanted species such as ba,ss into the fish pond. Escape of un\^lanted species from the fish pond could pose a problem for endangered speciee, in the rivers nearby. 8. Fish Pond Seepage study. This section summarizes a seepage study and proposes seepage control measures for the conversiqn of the abandoned sewage lagoon to a, fish pond. Assumptions made in the seepage study are also presented. The purpose of the seepage analysis vas to estimate seepage tosses resulting from the proposed deepening of the sewage lagoons. Seepage exit gradients were determined to evaluate the potential for heaving, uplift, or boils along the banks .01' the Uncompahgre River and the landside perimeter of the lagoons. The proposed fish pond is located within 150 feet of the Uncompahgre River, and the northern perimeter is within 540 feet of the Gt:.nnison River. The pond 'will impound water at elevation 4,926 feet. A portion of the abandoned sewage lagoons will be dE'epened 10 feet below existing grade. No load bearing structures will be located near the pond. Information on subsurface soils in the vicinity of the proposed fish pond was obtained from prior studies. Seven trenches were excavated and two 4-inch auger borings were drilled within 60C feet north of the sewa~e lagoons in a previous investigation for an aggregate source. Trench depths ranged frolT 6 to 16 feet, and the borings were drilled to refusal at 24.5- and 27-foot depths. Surface material was visually classified as silty 'sand of low to medium density having a layer thickness of 2 to 6 feet. Underlying material consists of gravel with sand and silt. The gravel is generally gap graded since j:jhe deposits lack the 1 to 10 millimeter sizes. The maximum gravel layer thickness encountered was 21 feet (27-foot boring) . 10