AL If you have read the earlier chapters of this book, you can identify the major factors which contribute to a safe water supply. By way of review, here are the points to consider: Is the seasonal high ground water table at least 7 or 8 ft below the ground surface? Is the soil at least as fine as medium-grained sand? Is there reason to suspect cracks and crevices in bedrock? Which way does ground water flow relative to the well and drain field, and how fast? Where is the worst place a neighbor could put his drain field? Are there plans for additional development in the area? How good is the water in nearby wells? The answers to these questions will give you a very good idea of whether or not you're buying into future drinking water problems, but you still need an idea of what density of development is too dense. Experience throughout the country indicates that, in general, half~ acre lots are too small. Three-quarter-acre lots are much better, and one-acre lots are often sufficient. This assumes, among many other things, that there is one single-family dwelling on the lot. If you want to develop a 5-acre mobile home park where there will be 4 acres of trees and 4 mobile homes on 1 acre using 1 septic tank and drain field, plan carefully. This also assumes that you will be living in a reasonably small subdivision. Hundreds of 1-acre lots together may well raise the nitrate concentrations to unhealthy levels or pro- duce water that smells bad and stains your clothes. Appendix FORMULAS Constants pi = 3.14 1 cubic foot = 1728 cubic inches 1 cubic yard = 27 cubic feet 1 acre = 43,560 square feet Water Constants 1 cubic foot = 62.375 pounds of water at 62°F 1 cubic foot = 7.48 gallons 1 gallon = 8.34 pounds = 231 cubic inches 1 foot of head = 0.433 pounds per square inch 1 pound per square inch = 2.31 feet of head 1 atmosphere = 34 feet of head 1 part per million ppm = 8.3 pounds per million gallons 1 horsepower = 550 foot-pounds per second = 746 watts Formulas Triangle: Area = 1/2 base X height Rectangle: Area If len