TENNESSEE VALLEY MARINA AND CAMPGROUND WASTEWATER CHARACTERIZATION SCREENING STUDY

The objectives of the marina and campground wastewater characterization study were to examine the makeup of holding tank deodorizers and additives and to characterize the wastewater from the pump-out systems to determine if these additives were likely to adversely affect onsite/decentralized wastewater treatment system (DWS) performance. The review of holding tank additives and deodorizers revealed that the most common active ingredients were formaldehyde, ammonium chloride compounds, sodium nitrate, quaternary ammonium compounds and bacteria cultures.Eleven marinas and three campgrounds across the Tennessee Valley were chosen to partner with TVA for the wastewater characterization aspect of the study, which took place in the summer of 2003. A one-time sampling event was conducted at each facility, with sampling taking place, as accessible, in the holding tank, in the septic tank influent (first chamber of the septic tank) and in the septic tank effluent (final chamber of the septic tank). The samples were analyzed for a variety of parameters including toxicity, bacteria, nutrients, biological and chemical oxygen demands, and oil and grease.Laboratory results showed that for most of these parameters the pump-out wastewater was highly concentrated in comparison to traditional residential wastewater. Of the samples collected in the final chamber of the septic tank, concentrations more than twice as strong as typical residential wastewater effluents were found in 50% of the BOD5 samples, 58% of the COD and total phosphorus samples, and 67% of the TKN and ammonia-nitrogen samples. These results validated a concern that DWS drainfields at marinas and campgrounds may be dosed with wastewater that is too strong to treat effectively. However, without an evaluation of the completely treated effluent quality below the drainfield, it is difficult to determine the effect of this wastewater on local water quality. A further study is in progress to examine the completely treated effluent exiting such heavily dosed drainfields to evaluate the treatment provided by the drainfield and soil. Our goal is to gather data to assist designers and regulators of marina and campground wastewater systems provide adequate treatment of these wastewaters to prevent impacts to water quality in and around their watersheds.