 per min, 0.13 horsepower is required. To lift water 25 ft at that delivery rate, 0.18 horsepower is required. A half-horsepower pump is adequate for most home applications. See the section on dosing chambers in Chapter 4 for more detail on pump selection. The dosing volume should be 5 to 10 times the lateral volume plus the volume of the supply pipe. In our example, we have 50 ft of 2-in. supply pipe, having a volume of in.)2 X 0.0408 X 50 ft = 8.2 gal There are 240 ft of 1-in. lateral with a volume of (1 in.)2 X 0.0408 X 240 ft = 9.8 gal Therefore, the dosing volume should be a minimum of (5 X 9.8 gal) + 8.2 gal = 57.2 gal With a flow of 300 gal per day, the absorption area would be dosed about five times per day. The preferred dosing frequency is two to four times per day, SO a better dosing volume would be 75 gal per dose. Actual water use will probably average less than 300 gal per day, which will reduce the actual dosing frequency and provide longer rest and recovery periods. As with sand mounds, no check valve should be used unless unique considerations (such as a one-bedroom house with sandy soil and large diameter distribution pipe) dictate that the distribu- tion system volume must be more than about one-fourth of the dose volume and unless, in addition, there is no danger of freezing. Materials 1. septic tank 2. dosing chamber, pump, alarm, and controls, risers 3. straight lengths of thin wall (160 psi) or schedule 40 PVC 4. PVC globe or gate valve for pressure adjustment 5. PVC tees, elbows, caps, and reducers 6. 1.4 yd³ of pea gravel (3/8 to 1 in.) or crushed rock per 100 ft of 6 in. CONVENTIONAL SYSTEM MODIFICATIONS wide trench with 9 in. of gravel fill. Get 10% more to take care of wastage. 7. drill, wheel barrow, shovel, saw, glue, wiring tools, etc. 8. backhoe and trencher Construction Prepare the site by clearing brush and small trees. Saw off larger trees at ground level and leave the roots in place. If fill is used to improve drainage characteristics or provide clearance to ground water or bed