Tag Archives: filtration

Autumn Rainwater System Maintenance

pollenThe dog days of summer in the Seattle area are nearing an end as the cooler, wetter days of Autumn approach.

With Fall rapidly approaching, bringing its gift of rainfall to the Pacific Northwest, rainwater collectors need to prepare for our harvest. Your quality of stored rainwater will be greatly enhanced if your system is ready. Gutters and screens should be cleaned of debris and residue, remembering to divert that water during this part of maintenance of your rainwater collection system. Keep an eye on those gutters during the windy times to be sure that they stay free of accumulation of leaves and needles.

Please remember to be safe with the use of ladders. The goal here is to send the cleanest water we can into our cisterns. You don’t want to send that yuck into your storage; it can decay quickly, cause odor and discoloration of your stored water. While carbon filters will help in the removal of odor, it is not as effective in eliminating discoloration (tannins). It is always a good idea at this time of year, to flush your downspout to storage conveyance lines. If you have clean outs installed, remove them and flush out any accumulation of sediment and/ or debris. If not, a garden hose flushing at each downspout to conveyance line is a good spot to conduct this simple task.

If your system has a sump tank and screen basket, give it the once over. A shop vac with the filter element removed makes this job easy by removing the sediment from the bottom of the sump. A teaspoon of bleach, mixed with about 10 gallons of water for a final rinse will help remove bacteria that may have accumulated during the summer months. Lift your float switch up inside the sump to activate your pump to be sure it is operational. You don’t want to find out that you missed out on collection because of a faulty pump or switch.

Skagit_FiltrationAutumn is also a good time to change your filters and your UV bulb. Most UV bulb manufacturers recommend that the bulb be changed once per year. They do have a life expectancy and begin to lose their intensity, which may result in improper disinfection. Your filters may have sat during vacation without circulation and could have allowed “festering” of the particulate that they have absorbed. Or, because of summer fun, you have not thought about changing them when needed – so it is time. I always shock my system this time of year. With filters removed but UV lamp turned on, add a couple of tablespoons of bleach into the first canister. Replace the canisters without the filters. Open each faucet until you smell a little bleach then close the faucet immediately. Repeat with all faucets in the household. Let the bleach water sit in the plumbing for about half an hour. Then, open all faucets and let run to flush the bleach out of the lines. Replace the filter elements and you’re done.

Good maintenance of your rainwater collection system will ensure the best quality of water available.

How to Move Collected Water From Tank

submersible-pumpTo move collected water from a tank for filtration and then use, installing a submersible pump or centrifugal pressure pump is necessary to get the job done. Additionally, if you go with a submersible pump, it will also need a way to manage and regulate movement.

A pressure tank with a pressure switch will tell the pump when to turn on and off by a drop of pressure in the pressure tank. This application is much like well system and is intended for household use. It could be used for irrigation, but keep in mind that the pressure tank will need to be frost protected.

centrifugal pumpThe most common method of conveyance would be a booster pump. These pumps are generally centrifugal pumps and can be placed in the mechanical room or well shed.

A centrifugal booster pump is used without an exterior pressure tank and is considered an “on demand” pump, meaning that when the faucet is opened, the pressure in the pump drops down to low pressure – usually 20 PSI, and the pump will start running and maintain constant pressure while the faucet is open.  Once the faucet is closed, the pump will continue to run until it meets its high pressure cut off.

It is important to remember that either pump system should always be used before filtration and disinfection.

This was first published as Part 7 in the series “How to Build a Rainwater Collection System”.  Click to see parts onetwothreefour,  five and six.

Rainwater is a Safe Source of Drinking Water

gutter-pipe-54531_640We know we can effectively capture, store, and use rainwater as a safe, viable source of potable water (drinking water) in Seattle and the Pacific Northwest.

A temperate climate offers rainfall throughout the year, including a little in most summers. With low intensity and high frequency rainfall, storage volume to use ratio is close to ideal. The autumn rain returns cisterns to high levels after summer usage and winter’s increased rainfall keeps them at optimal levels. As spring arrives, cistern levels continue to be supplied by less rainfall, but enough to allow summer demands to be met. The Pacific Northwest does not witness an extended “hard freeze” in the winter months as other parts of the country, allowing storage to be unaffected by most weather conditions. Marine winds help keep our air quality above average, with limited pollutants affecting quality. The same weather systems that produce snow caps for our municipal summer supplies also comes to us as rain in lower elevations, which can be stored for immediate and future use.

Storage is calculated by annual and monthly amounts, intensity, frequency, return period, and maximum number of dry days along with catchment area and surface runoff coefficients. Use or demands are based on number of occupants, fixtures, evaporation, efficiencies, indoor and outdoor requirements. Supply and demand equilibrium is compared to determine storage capacity, surplus/deficit, and level of storage. The frequency, return period and monthly amounts in Seattle and Puget Sound region can support whole house, year round use of rainwater collection.

An average 2,250 sq ft house in the Seattle area has the potential of collecting more than 53,000 gallons of water from its roof, rather than entering the storm system and accumulating contaminants before discharging in our waterways. Residential and commercial new construction is mandated to disperse roof runoff onsite, which is a good step toward protecting our waterways. But, why not use that water for our needs? Absorption type filtration, ultra violet light disinfection along with proper design, construction, and maintenance will allow homeowners to easily become their own purveyor of their own water source.

While most municipal water supplies are safe in the US, the recent water crises in Michigan and Ohio have brought public concern of quality and safety of our centralized water supplies. Costly repairs and replacement of an aging centralized water system will be required in the next 20 years. Rainwater collection is a viable, safe source of potable water for the homeowner in many counties in Washington State and elsewhere in the US and should be considered by those who don’t.

Rainwater collection helps protect our environment, conserves energy, decreases water contamination, helps prevent flooding, erosion and sewage releases into our waterways.

Tell your local government that you would like to see rainwater collection for single-family home potable use.