2. Yearly average of freshwater consumption for Appledore
Average (gpm)
Average per capita (gpm)
2001
1.19
2002
1.13
0.014
2004
1.06
2005
0.015
2006
1.27
0.012

3. Freshwater System:
There is a 20 foot dug well that is under the influence of surface water. This well supplies the island with its freshwater. All freshwater is chlorinated to meet the State of Maine drinking water regulations.
The well water is pumped into an underground holding tank (cistern). From the cistern the water is then pumped into a steel tank that is pressurized.

4. Note: Under high freshwater demands a Reverse Osmosis Unit (R/O) is used to desalinate seawater to meet the higher demand.
When the R/O is in use it dumps its freshwater product into the cistern for use to the island.
(More details later)

5. Another potential freshwater source is from direct collection of rainwater.

6. Average rainfall data for Appledore Island
May: 2.5 in/month
June: 3.0 in/month
July : 3.4 in/month
Three month average = 3 in/month

7. Compute rainfall collection area to meet freshwater demand.
Assume freshwater demand = 1700 gal/day
(blackwater currently uses seawater source)
Conversion units: 1 acre = 43,560 ft2
1 gallon = ft3
Water demand = 227 ft3/day

8. Rainfall intensity = 3 in/mon. = 0.1in./day

9. Complicating factors:
Need storage for leveling demand with rainfall.
Need to account for evaporation.
Need to treat for possible contamination,
(gull droppings, dirt blown into collection basin, etc.).
4. Need to disinfect.

10. Storage considerations:
Assume dry period = 1 month
Storage required:
A tank 20’x 20’x 20’ would satisfy this storage requirement