Browsing by Subject "Wastewater treatment systems"

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    Development of Alternative Onsite Treatment Systems [On-site treatment systems for domestic wastewater: A field comparison of alternative technologies] (1995-1997)
    (University of Minnesota Duluth, 1999) Axler, Richard P
    Approximately 500,000 Minnesota residences depend on individual or small community on-site wastewater treatment systems and 55-70% of them are either not in compliance with State Rules or are failing hydraulically to the surface. This is a direct human health threat from diseases, causes groundwater, stream and lake water quality degradation, and is a major impediment to the environmental and economic sustainability of the State’s water resources. The MTI projects over the period 1995-1999 keyed the development of an extremely successful state-wide partnership between the University (NRRI, UMD and UM-St. Paul), government resource & regulatory agencies (county, region, state and federal), and the private sector (engineering and consulting firms, contractors, vendors) to establish year-round, long-term performance, design criteria, cost-effectiveness and sustainability of alternative technologies for removing pathogens & nutrients from domestic wastewater. The program incorporates existing and newly created technology transfer and outreach/extension programs to efficiently transfer our findings to the private sector, to private citizens, to public planners and to policy makers to expedite potential changes in state or local rules. New business opportunities for new or existing companies have already occurred as a result of this project (>50 industry partners) and the total Match from 1995- 1999 was estimated to be $1,335,280 compared to MTI funding of $189,581 over the same period. Besides the business opportunities related to this project, effective alternative wastewater treatment systems will contribute to resolving some of our rural wastewater problems (e.g. affordable sewage systems for resorts and other commercial establishments throughout rural Minnesota) including the environmentally and politically sensitive northshore of Lake Superior, in addition to numerous other smaller, but sensitive lakes, and in geologically sensitive areas.
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    Freeze Survey Summary Report: Onsite Wastewater Treatment Systems
    (University of Minnesota Duluth, 2001-03) Reed, Jane; McCarthy, Barbara J; Henneck, Jerald; Axler, Richard P; Crosby, Jeff; Bauman, Heidi
    This report summarizes the results of an informal survey mailed to pumpers and contractors of onsite wastewater treatment systems in northern Minnesota in the spring of 2000. The survey was developed jointly by the Sewage Technical Committee (TC) of the Iron Range Resources and Rehabilitation Board and Northern Lights Tourism Alliance (IRRRB/NLTA). The purpose of the survey was to determine, in general, the types of freezing problems associated with onsite systems during the winter of 1999-2000.
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    Performance of a Recirculating Sand Filter Wastewater Treatment System Servicing the Iron Range Resources and Rehabilitation Agency
    (University of Minnesota Duluth, 2003-07) McCarthy, Barbara J; Monson Geerts, Stephen D
    Approximately 470,000 Minnesota residences rely on the use of onsite wastewater treatment systems and 27% of these systems may be in noncompliance with state rules or are failing to the surface. As part of a demonstration project to test new technologies in the region, a recirculating sand filter with shallow dispersal trenches was constructed and monitored at the Iron Range Resources and Rehabilitation Agency (IRRRA) office building near Eveleth, Minnesota in 1998 for a flow of 600 g/d. During the study period, flow averaged 520 g/d in summer and 492 g/d in winter, or 82-87% of design flow. Approximately 750,000 gallons of septic tank effluent (STE) have passed through the system to date, with the following STE quality: 166-178 BODs, 30 mg/L TSS, 10 mg/L TP, 64-80 mg/L TN, and 1,600,000 cfu/l00mL fecal coliform bacteria (pathogen indicator organisms). After only 3 years of operation, the septic tank was nearly full (80-90% ), presumably due to a significant loading of toilet paper, since the wastewater is largely human/toilet waste. The recirculating sand filter (RSF) performed well over the nearly 3 years tested at reducing wastewater contaminants before dispersed back into the environment. Average seasonal removal rates for the RSF were 92% removal of BOD5 (15 mg/L BOD5), 84% removal of TSS (5 mg/L TSS), 82-88% removal of fecal coliform bacteria (50,000-290,000 cfu/l00mL), 13-28% removal of phosphorus (8 mg/L TP), and 20-34% removal of nitrogen (42-64 mg/L TN). Secondary treatment standards for BOD5 and TSS were routinely achieved by the RSF, although pathogen levels were elevated in the effluent. Nitrogen removal (TN) was better in summer than winter, and the effluent was also more highly nitrified during the warmer season. Nitrate levels in RSF effluent, summer and winter, were similar (20-23 mg/L NO3). Temperature of the effluents were 15°C in summer, while winter temperatures averaged 9.5°C for STE and 7.5°C for RSF effluent. During the first 3 years, a single trench (120 fl:2) was used to disperse ~518,000 gallons of RSF effluent, at a loading rate of 4g/fl:2/day, with minimal ponding in the trench. Average daily flow to the soil dispersal trench was 500 g/d, but it varied from 187 g/d to 975 g/d. During the winter 2002-2003, both the forcemain from the pump tank to the soil dispersal system and the pressure line in each trench froze. To overcome this problem, a temporary forcemain was used to route RSF effluent into the old drainfield, which had drained almost entirely after resting for 21 months.