Thursday, October 10, 2013

Advice About Black/Green Algae in Irrigation Well

Hello, 

Looking for recommendations for my client's well. This is used for irrigation only, in Northern California. A well head approximately 400' deep pumps 5gpm to a 10,000 gallon cistern tank to hold water for irrigation. I noticed a slight odor to water and there is a black/green algae slime in some of the pipes. Thanks in advance for your time.

Sam

Sam,

Thank you for contacting us.  One very effective way to treat this water is to inject a small amount of chlorine, then filter it with a MangOX iron filter and fill the storage tank with clean water.  See the diagram below:

Click to enlarge
The MangOX filter can filter at 5 gallons per minute, but requires 15 gpm for a short backwash once a day.  The system is set up to backwash with the clean water from the storage tank booster pump.  The backwash water would need to go to the sewer, or into a leach field as it would be very rusty water.  During backwash: the well pump would shut down, a solenoid valve after the filter would close to prevent water from entering the storage tank during backwash, and a valve would open to allow clean water in from the booster pump to backwash the filter. 

The result would be disinfected, clean, odor-free, iron-free water with no slime or algae.  The small amount of chlorine present would be less than the amount found in city water, and have no effect on the plants or landscaping. 

Here is more information on these systems: 

Chlorination and the Stenner Pump Chlorinator System 

Chlorine is a low-cost and safe method of eliminating odors and bacteria, and it works great at oxidizing iron, manganese, and other contaminants in water so they can be filtered out.

45MHP10 Stenner w/ 15 gal tank 220V
Although there are other ways to eliminate microorganisms and odors in water, chlorination is the most commonly used because it is low-cost and effective.  Often combined with filtration, chlorination is an excellent and cost-effective way to disinfect drinking water supplies, eliminate odors, and oxidize iron and other metals.

For easy and accurate chlorine injection we recommend a Stenner Pump and solution tank system. The Stenner pump uses liquid chlorine bleach.  The system is reliable, easy to install, and very easy to use.  It can be adjusted to get just the right amount of chlorine needed for the application.

The chlorinator can be adjusted so the chlorine levels are very low in the household (similar to city water) or a low cost carbon filter can be installed to remove any trace of chlorine tastes and odors.
 
Tank Contact Mixing 40 Gallon 16x58
Contact Tank 

Contact tanks provide optimal contact time after chlorine, soda ash, peroxide or other water treatment grade chemicals have been injected into the water.  With a contact tank you can inject less solution and ensure that the solution being injected is thoroughly mixed and dissolved in the water.

These WellMate Contact Tanks are made of a seamless inner shell of molded polyethylene and are impact and corrosion resistant.  The tanks are high quality NSF/ANSI 61 certified tanks for drinking water.  Inlet and outlet connections are 1-1/4” but can be reduced to 1” or ¾” if needed. 

MangOX Iron Filter

The MangOX Iron Filter is a powerful and effective system for removing iron and manganese from well water. This system automatically removes iron, manganese, and sediment without the use of filter cartridges or chemicals. The iron filter is easy to install by any plumber or person familiar with basic plumbing.
MangOX Iron Filter 7000-SXT 2.5 CF
The MangOX Iron Filter removes both dissolved and oxidized iron and manganese by using a special type of solid manganese oxide media which traps the iron and then automatically backwashes out the trapped rust and sediment to drain.

The backwash lasts for approximately 15 minutes and takes place automatically, typically every 2 - 3 days, in the middle of the night when no water is being used. 

An optional chlorine solution tank is available to backwash the MangOX filter media with a chlorine rinse, which kills iron bacteria and can extend the life of the MangOX media for many years.  For waters containing “rotten egg odors” (hydrogen sulfide), a chlorine feed ahead of the MangOX filter can be used to kill the odor and keep the MangOX media working efficiently.
 
Unlike many residential and small commercial iron filters, the MangOX 7000 system will not restrict flow rate or cut down on water pressure in the home. The system uses a high quality Vortech filter tank which requires less backwash water, saving water and energy. 

Unlike the media inside the Greensand and Birm iron filters, which generally must be changed every 3 to 5 years, the MangOX media lasts for more than 10 years.