Laura Sewall of Phippsburg obtains all of her water from her roof. All of it. No well, no other supply pumped from a pond. Water for the dishwasher, toilets, sinks, showers, radiant floor heating systems, to irrigate her gardens and for drinking and cooking. So far, her catchment system has provided a plentiful supply for her and guests with hundreds of gallons to spare even during dry seasons.
This is the second time Sewall has harvested rainwater. Her first was more basic, similar to cistern arrangements found in many Maine homes and common on Caribbean islands. “I was living on the San Juan Islands [in the Pacific Northwest],” she explains, “young, doing the back-to-the-land thing. I had a 55-gallon drum on a stand under the gutter. There was a spigot that sent overflow from the drum to an underground tank. That was it.”
In her present, more sophisticated arrangement, water runs off the roof during rainstorms into gutters that send it along to four different pipes that merge into one larger pipe in her basement. There, the water can be routed to one or more than one of four 2,100-gallon tanks constructed of a special plastic designed to hold water for household use. The tanks are located in a 12- by 48-foot room in the basement, where they are lined up side by side along with a network of pipes that lead from tank to tank and others of PEX tubing that provide water for radiant floor heating.
Builder Christopher Hahn, who built the house, says he designed the network of piping and valves to be sure the system can handle any contingency. It has been in place for almost four years and has functioned perfectly.
To install the tanks, Hahn and Sewall rolled them down her driveway and through an opening in the house they had left for that purpose, then lowered them with ropes into the basement. Sewall points out that tanks could be kept in an outbuilding, as long as heat was provided to maintain them at 33 to 34 degrees F. Her tank room has radiant floor heating for extreme weather.
Sewall draws water from one tank at a time: she used just one-fourth of a tank for company at Christmas and into January. Before that, she used about two-thirds of another tank from September to Christmas. Her 1,600-square-foot roof provides 1,000 gallons of water to the tanks in one inch of rain. “The first time it rained, it was incredibly exciting,” she says. “I was up at 2 a.m. watching the water pour into the tanks. They were filled up in no time, it seemed.”
Since Hahn wanted to provide sufficient water for two or more people to live in the house, the tanks have more than enough water for her. Using statistics on rainfall in the area, he calculated what he thought would be needed. Sewall adds that they decided they should allow for several months when the gutters might be frozen and water couldn’t enter, or when it snowed and then snow fell off the roof in chunks rather than melting into the gutters.
“We figured there should be enough to last from December to April, just to be safe,” she says, and notes that having a plentiful supply makes it possible for her not to worry about being sure tank valves are open for every rainfall.
When water is needed for use in the house, it is pumped into a pressure tank and then passes through two cartridge filters located on the pipes, one for coarse grain sediment, one for finer particles. (There is a third cartridge filter Sewall hasn’t been using.) The water then passes through a Sterilight UV filter, which sterilizes it, eliminating the need to use chemicals. Sewall replaces the cartridge filters every few months; the UV light bulb needs to be replaced every nine months. A high efficiency Polaris propane water heater provides hot water for the radiant floor heating system and other household uses.
Sewall, who is executive director of the recently formed Kennebec Estuary Collaboration, made provision for many sustainable features in her home like utilizing maximum solar advantage, the most efficient insulation and energy efficient appliances including a Con/Serv refrigerator. She says she chose to install this catchment system principally because she wanted to have minimum impact on the environment surrounding her home, which is located close to wetlands of an estuary of the Sprague River. She and Hahn calculated that the expense of installing the catchment system was close to having a well put in, around $4,000. She is happy that she is able to use soft rainwater rather than well water, which in her area is notoriously hard and requires intense treatment for household use.
Sewall says the only thing she believes she would change in the system’s design would be to give better protection to the gutters so she wouldn’t have to clean them as often. They are open, and have a screen at the down pipe entrance to catch larger debris.
Christopher Hahn says he is happy to talk with people who would like more information. They can contact him through his web site www.houseworks.com or call him 207-389-1628.