BEYOND THE BASIC SEPTIC SYSTEM: PRACTICAL ALTERNATIVES by Bruce Coldham Since the late 19th centurv. when bathrooms moved from the garden to the back of the house, the main goal of wastewater treatment has been to keep the organic solids from becoming smelly and infectious. With the growing environmental concern today comes a second goal—to avoid groundwater contamination. The nitrates and phosphates found in domestic effluent (wastewater) must be contained. The basic septic tank and soil absorption system, which graces almost onethird of all U.S. housing, is the timehonored, on-site solution to achieving goal #l. But, in its current form, it does little to satisfy the second. A 500- to 1,500-gallon tank receives sewage, and holds it for a few days during