Environmental Alternatives

     The INFILTRATOR with micro-leaching chambers is an effective improvement over standard gravel and pipe drainfields.  The infiltrator units measure 3'x6'x1', weigh about 30 pounds, are available in 12" or 15" depth, and can store 66 gallons (standard) or 110 gallons (high capacity infiltrator); this storage volume is three or more times greater than a gravel trench.  These sections fasten together with self-drilling screws, and the entire system can be delivered in one pickup truck and installed by one person with a backhoe, level and rake.   The entire bottom of the trench provides a perfect unmasked infiltrative surface, the side wall is designed to minimize the masking effect, there is no vertical silt intrusion, and the micro-leaching chambers create voids for optimal biomat formation and the 1/4" slots provide open area equal to the porosity of the sides of a gravel trench. These structurally tested infiltrators are great for drain fields, mounds, pressure systems, and storm water management.  They are made in Connecticut, and are locally available.
 

• Simple
• Energy efficient
• Low maintenance
• Low power consumption
• Adjustability to peak loading or idling
• Low construction cost for both new and repair systems
• Can be expanded and added onto to meet new volume requirements
• Can replace or upgrade old or failed systems that do not meet current discharge standards

Here it is!  At last there is a gray water treatment system that works for both single family residences as well as for entire communities.
The AIRR (Alternating Intermittent Recirculating Reactor) system is a breakthrough in blackwater systems, and is an innovative alternative for the conventional drainfield. Because it is actually designed to treat blackwater (toilet water), it most definitely will handle greywater, particularly when combined with low-flush composting toilets.
    Approved by the state of Washington as a standardreciruclating sand filter, it solves some perk problems by turning sewer effluent into reusable water biologically and with no offensive odor.  The treated water is many times clearer than EPA swimming standards.  This clear sparkling water is suitable for futher processing and for recycling and re-use in non-potable applications.  The AIRR clear water can be discharged underground into drainfields, or into salt water, streams and rivers, or can be used to irrigate golf courses, parks, ski resorts, forests or farm land.
    The system consists of a septic/dosing tank, a biological reactor containing both secondary and tertiary sections, a simple cover structure, a recirculating tank and a discharge tank or pipe; circuit board control is an option.  The size of the reactor depends on the amount of gallons that need to be processed per day.  The reactor's size is based on five gallons per square foot per day.  An AIRR system can be designed for a single residence or an entire community. The AIRR system has many features.  One is low maintenance.  Regular septic tank pumping, periodic visual inspection of the sprinkler heads and pumps, and normal routine maintenance of the cover structure is all that is needed.  Other features include low construction cost for both new and repair systems, energy efficient low power consumption, adjustability to peak loading or idling, it can replace or upgrade old or failed systems that do not meet current discharge standards, and the system can be expanded and added onto to meet new volume requirements.
    So why doesn't everyone with problem soils use an AIRR system?  It's like a miniature sewage treatment plant with tertiary treatment!  Because most counties still insist on subsurface disposal of all water, whether gray or black.  This means that most counties still insist that a drainfield, mound system, sand filter, or leach field be installed, regardless of the water's cleanliness, for single-family residences.  If the system is used by a community and a maintenance person supervises its operation, then the state will permit discharge into existing waterways in most areas.  Having been producing excellent results since 1977, the AIRR manufacturers claim that drainfields could be reduced by 90% down to only 10% of the normal requirements. Unfortunately, some counties do not trust the individual homeowner to maintain such a system properly, so it is important to check with your local county authorities.  The AIRR system is made in Henderson, near Las Vegas, NV.

This proprietary product is listed in the department's List of Approved Systems and Products (http://www.doh.wa.gov/ehp/ts/WW/approved-list-oct-2004.pdf). It is classified as a Packed Bed Filtration / Attached Growth Process (P. 18). It is also listed as meeting the BOD and TSS parameters for Treatment Standards 1 and 2, but must use disinfection to meet the 3rd parameter of these treatment standards, Fecal Coliform. This information is on pp. 34-38 of the above-cited List of Approved Systems and Products.

The department's policy and recommended standards and guidance regarding gray water (a.k.a. greywater) are contained in the Recommended Standards and Guidance for Water Conserving Onsite Wastewater Treatment Systems (http://www.doh.wa.gov/ehp/ts/WW/WaterConservSystems-2000.pdf). Essentially you treat it as any other sewage discharge.

"Greywater systems are virtually the same as combined-wastewater on-site sewage systems.  Gravity flow greywater systems consist of a septic tank and a subsurface drainfield.  Pressurized greywater systems consist of a septic tank, a pump chamber or vault, and a subsurface drainfield.  Other types of alternative systems, pre-treatment methods and drainfield design and materials options may also be incorporated in greywater systems.

The primary distinction between a greywater system and a combined wastewater system is the lower volume of wastewater.   As a result the size of the septic tank and the subsurface drainfield is smaller compared to a system that treats and disposes of all the household wastewater (combined) through a septic tank and drainfield.

(To help assure that future household fixture and/or plumbing changes do not overload the greywater treatment and disposal system, the household and system plumbing must be clearly identified GREYWATER ONLY-NOT FOR COMBINED WASTEWATER .) "

The Brac Systems are approved in King and PierceCounties.

     The first question that comes with the topic of waterless toilets is whether or not a drainfield is still necessary.  The logical answer is no, but the legal answer is yes. Graywater -- sink, shower, bath and laundry water -- must be disposed of beneath the surface of the soil, unless you can think of an inexpensive way to evaporate it.  (If you do, call me.)  Although in the soil few viruses can survive very long since it is cold, the distance between grains of sand are great, and there are predators that eat viruses, still viruses can travel up to three feet from the source in dry soil; however, when transported in water, viruses have been detected thirty feet from the source and can even go farther. Consequently, in order to prevent the health hazards presented by contact with viruses, pathogens and bacteria, graywater must be disposed of in a drainfield, mound system or an approved leach field at least one hundred feet from any water -- pond, lake, house, stream, well, beach, etc.  In 1977 the state of Washington put out a set of guidelines approving composting toilets and allowing with their use a reduction of the septic tank
size by fifty percent and of the drainfield size by forty percent.  The size of a drainfield is determined by the number of bedrooms in the house, with each bedroom representing two full-time users.  The current state guidelines are even more versed in the application of alternative systems.  Ask DSHS in Olympia for a copy.  If you run into a political obstacle in your area, there are, remember, exceptions to everything and variants can be applied for.

This site is essential reading for anyone considering installing a greywater system. It covers the most common mistakes and misconceptions pertaining to greywater treatment and design, and answers the most frequently asked questions.  Go to www.oasisdesign.net

Create an Oasis with Greywate by Art Ludwig, revised Feb. 2000