For Spirit Rock Meditation Center
Woodacre, California

Questa completed field studies, feasibility analysis, and engineering design of wastewater facilities for a meditation retreat center in San Geronimo Valley area of Marin County. The design developed by Questa provides for: 1) septic tank and sand filter treatment systems, 2) central collection of septic tank effluent using small diameter and low pressure sewers, and 3) effluent disposal partially by means of a conventional leachfield system, and partially by shallow pressure-dosed trenches.

The two-phased construction called for an ultimate design wastewater flow of 9,000 gpd. The system was designed to maximize the use of the best available soil conditions, incorporate advanced treatment (i.e., sand filtration) for use of limited land area, provide for phased construction, and meet the strict site development constraints of the retreat center. Questa provided oversight and inspection of all wastewater construction work. Initial (Phase I) facilities were constructed in 1991 and have been monitored under permit conditions adopted by the Regional Water Quality Control Board. Phase II facilities were designed in 1996 and installed in 1997. Questa continues to provide operations consultation and monitoring assistance.