J. P. Villeneuve’s research while affiliated with Institut National de Recherche et de Sécurité and other places

Measurements downstream from refinery outfalls in the region of Montreal East have shown that, under favorable temperature conditions, the concentration of phenolic substances in the river water rapidly diminishes with distance from the refineries. Mass balance calculations at different transverse sections show that this decrease in concentration cannot be attributed to dilution only. Laboratory experiments performed on river water samples demonstrate the effects of water temperature and sterilization on the rate of phenol breakdown. Results support the idea that biodegradation is responsible for the self-purification of phenolics in the St. Lawrence River.

CAPDET is a computer program for estimating construction and operation costs of wastewater treatment plants. A validation study of the model was carried out in order to assess its capabilities for predicting these costs for Canadian conditions. The validation was performed using data from existing full-scale facilities located in Ontario, Québec, and other provinces. The validation study identifies problems in applying the model to Canadian conditions and formulates precise recommendations to account for them. Key results of the validation study were that construction costs can be predicted by the model to within ±20% of the actual costs and operation and maintenance costs to within ±30%. Key words: wastewater treatment plants, construction costs, operation and maintenance costs, CAPDET, computer program.

In the more populous watersheds of southern Quebec eutrophication of surface waters is a current problem, linked to excessive nutrient loadings from various municipal, industrial, and agricultural sources. A simple mathematical model has been developed to identify the optimal strategies for controlling nutrient loadings at various points in a river basin; for this optimization the key water quality parameter is phosphorus and the objective is to meet a fixed water quality criterion (0.06 mg total phosphorus per litre) at minimum cost.The potential utility of the model in a water management context has been demonstrated in a case study of the Yamaska River, Quebec, which drains regions of intense agricultural activity and is also subject to phosphorus pollution from numerous point sources of municipal and industrial origin.

Since 1978, the government of the province of Quebec has undertaken an important water pollution control program. Under this program, new wastewater treatment plants are to be constructed in many municipalities of the Yamaska watershed (Quebec) by 1990. From an engineering point of view, one of the major issues in planning the construction of these treatment facilities is the selection of the wastewater treatment alternatives to be implemented at each municipality of the watershed. Using case studies from the Yamaska watershed, the present study illustrates the role and importance of three factors for the analysis and the selection of wastewater treatment alternatives. These factors are (1) the standards, as related to the receiving stream, (2) the discharge point interactions through the receiving stream system, and (3) the various possibilities for joint or separate treatment of municipal and industrial wastewater. Examples are given of the economical implications that may result from these factors. While each factor was dealt with separately for the purpose of this study, it is clear that they are strongly related and that they interact. As a result, the selection of wastewater treatment alternatives is fundamentally a system-based problem rather than a case-by-case problem. Key words: wastewater treatment alternatives, treatment process, standards, receiving stream, stream system, joint treatment, separate treatment, wastewater treatment costs, decision analysis, systems analysis, Yamaska River, urban wastewater, industrial wastewater, economical implication.