| Popis: |
Limnological, bacteriological and biological data for Roblin Lake, a potential source of water supply for the village of Ameliasburgh, were collected on 5 days during the summer of 1970. Classical indications of mesotrophy and/or early eutrophy were evinced by relatively low Secchi disc readings; oxygen depletions and high phosphorus, nitrogen and iron concentrations in the lower waters; depression of pH in the deeper strata and by relatively high standing stock of phytoplankton dominated by the blue-green "water- bloom" alga Microcystis. Bacteriologically, Roblin Lake is an excellent source of domestic water supply. On the other hand water taken from the euphotic zone during the summer months would be extremely warm and would contain relatively high levels of those algae which produce tastes and odours. On the other hand, water from the deeper strata, albeit slightly cooler, would contain increased concentrations of iron, nitrogen (including ammonia), phosphorus and calcium and magnesium carbonates. In addition, relatively high levels of algae periodically develop in the deeper zones of the lake. Poor water quality would be experienced frequently by domestic users unless treatment facilities for algal removal and taste and odour control are included in the plant design. The expense of such facilities may not be justified in view of the small population to be serviced and the enriched nature of the lake. |
