One important thing to keep in mind when reserving a cottage is the "head count". This is the number of people, including children of all ages and guests, who will be occupying the cottage on the night of its greatest use; it is not an average. Each place has a specific limit set by the owner; in Eastham, the limit is established by the Board of Health. This is extremely important on the Cape because we are the only "single source aquifer" in the Western Hemisphere. Our fresh water supply is our ground water; we have no rivers or reservoirs, and we cannot over-use our water supply and risk intrusion from the sea around us. We also have individual septic systems on each property; unlike a city sewer system, each cottage can only process a certain gallonage a day, a limit which is controlled by respecting the occupancy limit.