Alternative Wastewater Treatment

Following the end of World War II there was a major migra­ tion of population in the United States and Scandinavian countries to urban areas. As a result of this migration and in part due to the public works moratoria imposed during the war, a major pro­ gram of sewer construction was instigated, which resulted in the collection and subsequent concentration of large volumes of waste­ water at single discharge points. As the assimilative capacity of these receiving waters was exceeded, it led to or aggravated existing water pollution problems in these waters. To mitigate this degradation of water quality a massive program to construct wastewater treatment facilities was instigated. In addition, large amounts of money were spent on research to improve the technology of the conventional collection and treatment concept. In contrast, the wastewater disposal problem of the rural home owner received little attention, and in most cases the septic tank soil absorption system (ST-SAS) was the interim solution. In recent years there has been a fundamental change in the population growth pattern in the US and Scandinavian countries. It appears that a great many people are moving back to rural areas where they seem to prefer the suburban or small town envi­ ronment, yet at the same time want all the conveniences of urban life. The provision of proper wastewater disposal facilities presents a very perplexing problem, because the capital and operating costs of conventional sewers are usually financially impractical for rural areas.

Contenu

Session I: Objectives of On-Site Wastewater Disposal.- Objectives of On-Site Wastewater Disposal.- Some Aspects on Norwegian Practice.- Session II: Quantity and Characteristics of Residential Wastewater.- Alteration of in House Wastewater Flow with Low Flush Toilet Fixtures and Graywater Recycle.- Session III: Research on On-Site Disposal Methods in the Us and Scandinavia - Past and Present.- On-Site Wastewater Disposal Research in the United States.- Research on On-Site Disposal Methods in Norway - Past and Present.- Research on On-Site Disposal Methods in Sweden - Past and Present.- Session IV: The Soil as a Renovating Medium.- Water Movement into and through Soil.- The Soil as a Renovating Medium - Clogging of Infiltrative Surfaces.- The Soil as a Renovating Medium - The Fate of Pollutants in Soil - Organic Material.- On-Site Soil Systems, Nitrogen Removal.- Phosphorus Sorption by Soil; A Review.- Modeling Phosphorus Sorption and Movement in Soils in Relation to Septic Tank Leach Fields.- Reduction of Enteric Microorganisms in Soil Infiltration Systems; Field and Laboratory Experiments.- Session V: Site Selection Criteria for On-Site Disposal Systems.- Evaluation of Site Suitability for Subsurface Soil Absorption of Wastewater.- Selection of Disposal Sites in Norway.- Session VI: Design, Construction, and Function of Septic Tank Soil Absorption Systems.- Subsurface Soil Absorption Systems used in the United States.- Practical Experience with Alternative Systems for Problem Soils in Norway; Alternative Wastewater Systems for Local Infiltration.- Session VII: Non Water Carriage System.- Norway Introduces Quality Standards for Biological Toilets.- Session VIII: On-Site Wastewater Treatment Methods.- Present Technology in Northern Europe On Wastewater Treatment Plants for Small Flows.- Treatment of Residential Graywater with Intermittent Sand Filtration.- Session IX: State Regulations and Policy Regarding On-Site Wastewater Disposal System.- Regulations and Policy Regarding On-Site Wastewater Disposal Systems.- Present Norwegian Practice and Activities for Improvement of On-Site Wastewater Disposal.- List of Participants.