WaterAgFair-3 Published on January 5, 2014 in 4 – SOLVIVA Wastewater GreenFilters – with flush toilets!Full resolution (1280 × 815) ← Previous Next → Sometimes the regulations require raised leaching mounds or bunkers filled with sand, costing $20,000-70,000. But they cause just as much nitrogen pollution as a below-ground leaching field.