TY - JOUR
T1 - Residential subsurface flow treatment wetlands in northern Minnesota
AU - Axler, R.
AU - Henneck, J.
AU - McCarthy, B.
PY - 2001
Y1 - 2001
N2 - Approximately 30% of Minnesotans use on-site systems (∼500,000 residences) and >50% are failing or non-compliant with regulations due to restrictive soils and site conditions. Many sites occur near lakes and streams creating health hazards and deteriorating water quality. SSF CWs have been evaluated year-round at two northern sites since 1995. The NERCC CWs simulate single homes and the Grand Lake demonstration CW treats STE from a cluster of 9 lakeshore homes. Systems were generally able to achieve design criteria of 25 mg TSS/L and 30 mgBOD5/L and the NERCC CWs required only 0.3m of unsaturated soil to achieve consistent disinfection to <200 fecals/100 mL year round. Seeding experiments with Salmonella indicated removal efficiencies of 99.8% in summer and 95% in winter. High strength (∼300 mgBOD/L, 95 mg TN/L) influent at NERCC probably limited system performance, particularly N-removal (mass) which was ∼42% in summer and 20% in winter. The data indicate CW's are a viable, year-round treatment option for homeowners in terms of performance, ease of operation, and cost but require additional maintenance related to inconsistent vegetation growth, winter insulation, and meeting concentration-based regulatory standards since they were seasonally and annually variable due to rain events, partial freezing, spring snowmelt, and summer evapotranspiration.
AB - Approximately 30% of Minnesotans use on-site systems (∼500,000 residences) and >50% are failing or non-compliant with regulations due to restrictive soils and site conditions. Many sites occur near lakes and streams creating health hazards and deteriorating water quality. SSF CWs have been evaluated year-round at two northern sites since 1995. The NERCC CWs simulate single homes and the Grand Lake demonstration CW treats STE from a cluster of 9 lakeshore homes. Systems were generally able to achieve design criteria of 25 mg TSS/L and 30 mgBOD5/L and the NERCC CWs required only 0.3m of unsaturated soil to achieve consistent disinfection to <200 fecals/100 mL year round. Seeding experiments with Salmonella indicated removal efficiencies of 99.8% in summer and 95% in winter. High strength (∼300 mgBOD/L, 95 mg TN/L) influent at NERCC probably limited system performance, particularly N-removal (mass) which was ∼42% in summer and 20% in winter. The data indicate CW's are a viable, year-round treatment option for homeowners in terms of performance, ease of operation, and cost but require additional maintenance related to inconsistent vegetation growth, winter insulation, and meeting concentration-based regulatory standards since they were seasonally and annually variable due to rain events, partial freezing, spring snowmelt, and summer evapotranspiration.
KW - Alternative technologies
KW - Cold-climate
KW - Constructed wetlands
KW - Pathogens
KW - Wastewater
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U2 - 10.2166/wst.2001.0850
DO - 10.2166/wst.2001.0850
M3 - Article
C2 - 11804117
AN - SCOPUS:0035676344
SN - 0273-1223
VL - 44
SP - 345
EP - 352
JO - Water Science and Technology
JF - Water Science and Technology
IS - 11-12
ER -