PEAT LEACHMOUNT TREATMENT OF RESIDENTIAL WASTE-WATER IN SUB-ARCTIC ALASKA

In many areas of the North, conventional septic systems cannot be inst alled or have failed because of inadequate drainage. Conventional dome stic, on-site wastewater may contaminate shallow water tables and surf ace waters. The effectiveness of two pilot peat leachfields in treatin g septic wastewater was investigated for approximately two years by co mparing the quality of the untreated wastewater collected from the sep tic system lift stations to the quality of the peat leachate. The qual ity of the leachate, based on parameters such as BOD, COD, TSS, NO3-N, TKN, total-P, pH, fecal and total coliform bacteria, color, turbidity , and DO, is similar to wastewater that has undergone tertiary treatme nt. Temperatures below the leachmound distribution pipes ranged betwee n 1-degrees and 6-degrees-C. Clogging of the interstices with an organ ic slime was not encountered. The results of the study show that peat leachmounds can be adopted to treat residential wastewater in rural su b-Arctic Alaska and other northern tier countries without compromising ground or surface water quality.