Because of site specific factors such as clayey soils, excessive slopes. seasonal soil wetness, and rapid 'perc' sands, the conventional septic tank-soil absorption system has had a high rate of malfunctioning in lake and coastal shore developments. Because of high density of development in close proximity to these waters of Texas, alternative systems were needed which offer enhanced treatment of the wastewater and maximum protection of water quality.
The systems selected and currently utilized to meet the goals of the program include both surface and subsurface irrigation preceded by aerobic pretreatment and disinfection of the wastewater. These systems are being utilized for individual homes as well as for cluster developments such as RV and mobile home parks.
The Trinity River Authority CTRA) has conducted a limited performance evaluation of the pretreatment systems over a two year period. Ninety-two wastewater samples were collected from a total of 81 aerobic on-site treatment units installed around Lake Livingston, a major recreational lake for the state. These units included small systems serving as pretreatment for both surface and subsurface irrigation systems for individual homes and larger treatment units serving RV and mobile home parks.
To date, irrigation of wastewater by both surface spray and subsurface trickle irrigation has been generally successful in treating and disposing of wastewater with little or no impact of surface water quality. By reducing septic tank failures around the lake, overall lake water quality should be enhanced by expanded use of these alternative systems in the future.
Waste systems for lake and coastal development