COLORADO ONLY - Infiltrator chamber septic system leach fields. Installation guidelines, design tips, and recommendations for the optimal longevity

​The Infiltrator chamber septic system leach field differs from conventional leach fields, which use perforated plastic pipes laid in a twelve inch gravel bed. It is not a stretch of the imagination to envision those small holes clogging faster than a three foot wide chamber. That's why TheNaturalHome.com only sells the best! Infiltrator chamber leach field units are high-density polyethylene arches that interlock to form a continuous drainage area with a much greater storage 'surge' volume than conventional pipe leach fields. Structurally, chambers will take a heavy load, so you may drive over when necessary, just be sure to drive perpendicular to the chamber (like crossing rail road tracks) and never driving down the length of chambers. Installation simply involves digging a series of three foot wide trenches (or a large rectangular bed as shown below), connecting the Infiltrator chambers, and backfilling with the soil you originally removed. As a general rule, trenches 'fingers' should be no longer than fifty feet (12 or 13 Infiltrators long) for best function and most even effluent distribution. Unless you are installing as a "bed" system (where the chambers are right next to each other), leave at least six feet of undisturbed soil between fingers. In practice, this six feet of undisturbed soil between trenches becomes eight feet or more since you don't want to compact the soil above the Infiltrators; one should allow at least the width of the backhoe between trenches. And don't forget to loosen the soil twelve inches below bottom of the trench (scarify) before installing the Infiltrators leach chambers. The worst mistake you can make is to compact (smear) the soil in bottom of a leach field trench. You want to be sure to loosen the soil to allow for proper percolation of effluent. No gravel is needed - but gravel is always an upgrade option to aid percolation in any soil. No geotextile fabric (weed barrier material) is need - but in sandy and silty soils, it is recommended to cover the tops of your chambers with gravel and then fabric to keep soil from migrating into the chambers and surrounding gravel. For even more protection, fabric can be placed atop the chambers and then covered with 3/4 inch nominal crushed stone and then yet another layer of fabric atop the stone. Over-engineering is excellent insurance for long-term viability. As with most construction projects of this scope, it is always best to do the job right the first time.

Please note we are not Infiltrator®, the manufacturer, and we do not ship Infiltrator plastic septic tanks or Infiltrator chamber leach field systems outside the state of Colorado. For out-of-state referral, please contact the manufacturer direct at: infiltratorwater.com e-mail: info@infiltratorwater.com or phone: 800-221-4436. Infiltrator chambers and plastic injection molded septic tanks are delivered free by company truck within about 50 mile radius of Denver (North to Fort Collins and Greeley, South to Monument and Franktown, West to Georgetown and Bailey, and East to Deer Trail and Tampa) or provided will-call, pick up in person at the Denver area warehouse. Motor freight for such large items has become so expensive we no longer quote out-of-state shipments of septic tanks, and chamber systems, but any local distributor of plastic storage tanks and PVC pipe is capable of sourcing septic tanks and chamber systems for your project. After purchase, we encourage clients to mail copies of their septic system permit plans for our review, as there are always details that could use some small improvement... with any engineered and approved plan. We'll do our best to help you avoid critical mistakes, like not using risers or not venting your leach field properly. We offer a 3% cash discount for payment other than credit card (bank wire transfer, bank cashier's check, or US Postal money orders). For invoice and scheduling delivery, please e-mail service@thenaturalhome.com with parts cut-list and drop site location along with best telephone number for driver to use in-route. We can normally schedule an AM or PM delivery when given at least three days advance notice, weather permitting. Driver requires assistance unloading merchandise.

​Infiltrator Quick4 Plus Standard chambers 34" wide by 48" long (net assembled) by 12" tall
this updated 'Plus' series features internal support legs and better mounting for distribution pipe (when installed)
Infiltrator Quick4 Plus chambers weigh about 13 pounds each and a full pallet of 85 chambers is 7 foot 6 inch tall

FREE truck delivery only in Colorado. We do not ship chambers or septic tanks outside Colorado.
Delivery radius about 50 miles around central Denver. Or you can will-call pick up in person at yard.
Infiltrator Septic Tanks are also available for free Colorado delivery with leach field chamber orders.

$33 each discounted to $31 at 50 count and $29 for full pallet load of 85 chambers or more
$20 each All-In-One 12 multiport end caps can also be installed in middle of chamber rows
$45 for 7-Hole Distribution Box or $55 for 9-hole includes seals & plugs - 6 inch risers $20


3% Cash Discount when your order is paid with bank cashier's check or US Postal money orders
For invoice, email with address and parts list to: service@thenaturalhome.com or fax: 720-293-1705
We can usually arrange AM or PM delivery choice with payment at least 3 days in advance


Infiltrator Quick4 Plus Standard chambers 34" wide by 48" long (net assembled) by 12" tall
this updated 'Plus' series features internal support legs and better mounting for distribution pipe (when installed)
Infiltrator Quick4 Plus chambers weigh about 13 pounds each and a full pallet of 85 chambers is 7 foot 6 inch tall
FREE truck delivery only in Colorado. We do not ship chambers or septic tanks outside Colorado.
Delivery radius about 50 miles around central Denver. Or you can will-call pick up in person at yard.
Infiltrator Septic Tanks are also available for free Colorado delivery with leach field chamber orders.

$33 each discounted to $31 at 50 count and $29 for full pallet load of 85 chambers or more
$20 each All-In-One 12 multiport end caps can also be installed in middle of chamber rows
$45 for 7-Hole Distribution Box or $55 for 9-hole includes seals & plugs - 6 inch risers $20

3% Cash Discount when your order is paid with bank cashier's check or US Postal money orders
For invoice, email with address and parts list to: service@thenaturalhome.com or fax: 720-293-1705
We can usually arrange AM or PM delivery choice with payment at least 3 days in advance

Infiltrator® chamber leach field systems are far superior to pipe-in-gravel in every aspect: smaller leach field size due to optimal percolation, increased retention capability for heavy loading days, root infiltration protection for long term viability, and resistance to traffic with 16,000 pounds per axle load rating given at least one foot of cover. Driving over the top of a leach field is not recommended, but you can on occasion, just be sure to drive perpendicular (from the side) not down the length of a run. You don't need to hire an engineer to design your septic system in most counties. We do not supply any engineering services. Local regulatory officials normally allow you to submit a site plan and pull your installation permits as the homeowner-builder as long as the soil percolates well. Then you can save even more money by renting a backhoe and installing your own septic system! Installation is relatively straight-forward, but even seasoned professionals can get too mired in 'how they've always done it' to realize there are better ways to approach any project. We're here to help every step of the way, doing our best to ensure you don't make that one critical mistake, like not venting your leach field properly or not scarifying the base of your trenches. We encourage clients to mail copies of their septic system permit plans for our review after purchasing a system, as there are always details that could use improvement with any plan. Building codes and engineered site plans are never intended to reflect optimal design specifications, merely the minimum acceptable requirements.

Infiltrator septic chamber leach field installation versus pipe in gravel stone and pipe

how to build it yourself septic leach field design tips and general rules-of-thumb

  • Limit field runs to +/- 12 or 13 chambers which is about 50 feet in total length
  • Always bring effluent pipe in top of chamber end cap, never into the bottom
  • Install large granite or durable ceramic tile underneath inlet for splash plate
  • Always ventilate the ends of every leach field pipe run or set of chambers
  • Loosen 'scarify' soil at least one foot in base of trench before backfilling
  • Add gravel into base of trench and atop chambers to improve longevity
  • Geotextile fabric prevents soil intrusion into gravel from above & sides
  • Never install geofabric in the bottom of any trench or septic leach field
  • Septic tank up to 10 feet away and leach fields 20+ feet from foundation
  • Leach field, especially pipe-in-gravel, should be 20+ feet away from trees
  • Never plant bushes or deep-rooting fescue, dichondra, brome, or rye atop
  • Never drive over a septic tank or leach field - chambers perpendicular only

Standard Quick4 'Plus' Infiltrator chambers are 34 inch wide (3 foot trench) by one foot tall by four foot long (net length after connecting together) and cost $33 each, $31 each for 50 or more, and $29 each for a full pallet load of 85 chambers or more. We offer a 3% cash discount when paid with bank cashier's check or US Postal money order (instead of MasterCard or VISA) and free delivery within about 50 miles of Denver or will-call pickup in person at Denver area warehouse. Rows of Infiltrator are generally limited to 12 or 13 chambers (about 50 foot length) requiring two $20 end caps for each row. Note that the 'plus' series end caps can be installed in the middle of a run to feed both directions (still need one for each end). We offer a 3% cash discount for payment other than credit card (bank wire transfer, bank cashier's check, or US Postal money orders). Please e-mail service@thenaturalhome.com with a cut-list for your project to get a personal quote. In addition to your parts list, please provide the drop site location and we can confirm free delivery is available in your area. In average soils, budget around $2000 for two bedroom home leach field, $2500 for a three bedroom, and around $3900 for a complete 4 bedroom Infiltrator chamber leach field system by the time you factor in distribution box, pipe, and vent fittings. Total package price depends upon leach field layout (bed versus trench) and number of Infiltrator chambers required, which is not known until you get a soil test and a copy of the local Individual Sewage Disposal System ISDS regulations. Local building code supplies the equation used to calculate leach field size in the ISDS: number of bedrooms multiplied by the factor of percolation rate of the soil with a percentage reduction in size given for using Infiltrator chambers. We can quote the system after you supply us with a cut-list detailing number of chambers and end panels and whatever other fittings you may require, but we do not supply engineering services to determine how many chambers you will need.

Infiltrator Quick4 Plus standard chamber dimensions

All of the various 'gravel-less' leach field chamber system brands function by the same set of physical limitations, regardless of marketing claims. 'Required' installation tips are not to be implied, but there are always 'good, better, best' methods of approaching any construction project. 'Good enough' with chambers is digging a level trench and backfilling atop with native soil. 'Better' is to scarify (loosen and rake) the soil in base of trench to a depth of at least one foot before installing chambers. 'Best practice' is adding a 6 to 8 inch layer of crushed gravel to scarified soil to ensure long-term percolation and best sewage treatment. Some engineers go one step further and lay 2 inch diameter perforated pressurized distribution pipe in the top of chambers with 1/4 inch diameter holes every 2 foot facing upwards to ensure equal effluent introduction throughout the trench. This only works with a lift station 'dosing tank' to send a couple hundred gallons of effluent out at one time. Non-pressurized (no pump or dosing tank) systems do not benefit from distribution pipe since the larger 1/2 inch diameter holes must face downwards and effluent rarely reaches the end of even a short run of chambers. When specified, non-pressurized systems strap 4 inch perforated pipe either side of the structural columns found on Quick4 Plus design. It is not recommended to run distribution pipe along the base of the trench since that area can be flooded at times should percolation rate be slow. Several inches of gravel atop chambers with a layer of geotextile fabric on top and sides is common practice in sandy or silty soils. Best practice is to limit trench lengths to about 50 foot (12 to 13 four foot long chambers) for full trench saturation and best treatment of septic effluent. Always vent the ends of each chamber run to ensure healthy air flow through system. Inspection port at end of each run must be drilled with holes to allow venting. Air is pulled through the chambers and out the plumbing vent atop roof of house. Fresh air and healthy soil are critical for long-term viability of the leach field. Standard ventilation specification is 1/16 inch (up to 1/8") diameter holes drilled at least one every square inch for at least eight inches above finish grade and capped. Larger holes are discouraged to prevent insects from nesting in the vent port.

Do-it-yourself infiltrator chamber leach field sewage disposal system basic conventional bed style layout

"Are we allowed to install this septic system on our property" is not a question we can answer for you. We have been providing much the same passive (non electric) septic system parts for over twenty years now, but we do not follow constantly changing city, county, and state building regulations. Unfortunately, with 63 counties in Colorado, regulations changing from year-to-year, and interpretations of those rules varying from one inspector to another, it's never possible to say for certain 'what is allowed' locally. Your local county building department is your primary source of information on what is possible to install according to local 'code'. Rather than telephone them with questions, you should drive over in person and get a copy of their local Individual Sewage Disposal System ISDS Regs and also get a list of locally licensed soil engineers. The building department will confirm or revise your site plans once submitted for approval. Often the county inspector will assist you with site plans and design as a service provided for their permit filing fee. If not, they will refer you to a local engineering firm that can visit the property in person and design the system. We provide free consultation after the sale on installation procedures, system design improvements, and operational issues, but we do not provide any soil testing, on-site services, 'stamped' engineered plans, or 'advanced treatment' systems.

There is no accurate method to calculate how many Infiltrator chambers are required without digging test pits in area of leach field. A percolation test performed at depth of leach field can approximate soil absorption rate, but only a test pit at least six feet deep will confirm soil composition beneath the leach field, ensuring proper waste treatment is possible in the critical first three feet. Number of chambers is determined with soil/usage equation supplied by local building department which varies from county-to-county, let alone state-to-state. That equation typically takes into account '1.5 engineering factor' which includes 50% extra for long-term viability. <b>A very general 'rule-of-thumb' minimum size is "one square foot per gallon per day" and that could be way off, depending upon actual soil percolation rate and estimate of daily usage.</b> Bare minimum usage rate to estimate with is 100 gallons per person per day. Therefore the building department often uses 200 gallons per bedroom per day when sizing residential systems. Each chamber is 12 square feet of base area and 8 square feet of sidewall area. For instance: 2 bedroom home may be calculated locally as 2 x 200 = 400 x 1.5 = 600 gallons per day usage. If you are given credit for sidewall percolation from trench chambers, that is 600 divided by 20 = 30 chambers in well percolating soils. More conservative approach (less well percolating soils) would be to estimate using only the base area of trench: 600 divided by 12 = 50 chambers. There is a huge difference between what is 'possible' to percolate daily and what is best for sewage treatment to prevent contamination of groundwater. The larger the leach field, the better the treatment of wastewater. This is a critical factor when there is a well drilled within 200 feet of leach field location and/or you have seasonally high groundwater present that could prevent proper treatment of sewage.  

/infiltrator/

Flow director valve for splitting septic effluent 50/50 or all one direction

Flow director splitter valves are far superior to distribution boxes or splitting effluent flow with a tee fitting manifold. Effluent flow can be split 50/50 evenly between the two outlet lines OR alternate the flow 100% to one side or the other. This allows one half of your leach field go fallow for few months to revitalize soil, prevent overloading, and reduce the growth of bio-mat. Three director valves will allow splitting flow between four separate leach field lines. And seven director valves will allow splitting flow between eight separate leach field lines. You can stagger installations with an even number of diverter valves, splitting flow into unique percentages to dial-in percolation area saturation. Director valves make for a very professional and longer lasting leach field versus using often wildly inaccurate distribution boxes or tee manifolds.

Director Valve Kits are $69 each with discount for quantity
comes with threaded access cap, riser pipe coupler, and flow adjustment handle FREE Shipping to 48 states – in stock for quick shipment by the next business day $69 for 1, $66 each for 2, $63 for 3, $61 for 4, $59 for 5, $57 for 6, and $55 for 7+ valves – discount displayed in cart

Flow Director Valve

$69.00


flow director splitter valve additional images, design details and installation guidelines

 


Geotextile Fabric - professional duty for use with Infiltrator chambers

While not 'required', it is best practice to place a layer of gravel atop the chambers and cover with geotextile fabric before backfilling atop in sandy and silty soils. This additional step is recommended when soils are loose or sandy and would otherwise tend to wash down into the chambers. The primary place for geotextile fabric is above the gravel layer of your leach field lines, French drain, or drywell leach pit. Additionally, one can line the outside walls/sides of the excavated leach pit or drain lines to keep soil from migrating into the gravel from sides. This sidewall protection is always recommended when soils are loose or sandy and would otherwise tend to wash soil into the gravel. Geotextile fabric is also used for wrapping perforated pipe-in-gravel French drains, as pictured at right, with fabric on the bottom of trench too. French drains are wrapped like a burrito, unlike septic leach field chambers where the fabric is on the top and sides only. Protecting your leach chambers and perforated pipe gravel from soil and root infiltration is crucial to long-term soil percolation and preventing leach field failure.

Never install plastic 'visquene' sheeting or cheap non-woven 'weed barrier' landscaping fabric in place of professional grade heavy-duty woven geotextile fabric for septic system leach fields, drywell pits, French drains, or soil stabilization in foundation drainage projects. Besides longevity, the problem with using visquene plastic sheeting or cheap weed barrier non-woven materials, is they suffocate the soil, ultimately causing anaerobic soil conditions, biomat formation, root rot, and molding issues. Plastic sheeting becomes brittle and tears within a few years and the adhesive bond holding non-woven weed-barrier fabric together eventually decomposes, slipping, ripping and tearing, and allowing sand and soil to migrate into the gravel drainage layer of leach field or French drain. Invest in our professional grade woven geotextile fabric with a full 35 mil thickness and extra heavy-duty five ounce per square yard weight. Built for a lifetime of service, this is one of the only 'hydrophilic treated' materials on the market, with needle punched, multi-layer woven polypropylene design technology that lets air, water, and nutrients through, but keeps the soil out. Hydrophilic fabrics are critical in septic and greywater leach fields where oxygen penetrating into the soil is vital for long-term performance and protection against soil percolation failure. Unlike most fabrics, it features a very functional 'fuzzy' side that lays down against the soil to prevent slippage, making it very easy to install on sloped ground. The shiny smooth side has printed stripes every foot on center, full-length, for gauging trench elevations, rock fill levels, or lining up plants. Click here for our geotextile soil fabric engineering specifications and material MSDS sheet. This professional grade geotextile polypropylene fabric has proven itself over time to be a superior performer, as compared to other '20+ year landscape fabrics'.

Professional strength, heavy-duty woven 35 mil thick geotextile fabric is hydrophilic treated to allow air, water, and nutrients through its needle punched, multi-layer technology construction.French drain trenches install fabric on all sides to prevent dirt from entering the gravel layer around perforated pipe.Septic wastewater disposal lateral lines and leach pits do NOT install fabric on the bottom side, underneath gravel. FREE UPS Ground to 48 contiguous states – No USPS mail box, APO/FPO, Alaska, Hawaii, Mexico or Canada

3, 4, 5 and 6 foot wide professional-duty geotextile soil fabric 30, 60, 90 and 120 foot long pieces or full 250 foot long rolls

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6 Foot Wide
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250 foot long full rolls of professional-duty geotextile soil fabric

Quantity discount of 7.5% for 2 full rolls10% for 4, 12.5% for 6, and 15% for 10 In stock, ships within 2-3 business days. 12 foot wide by 250 foot long full rolls available by special order in quantity.
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The primary place for geotextile fabric is above the gravel layer of your leach field lines, French drain, or drywell leach pit. Additionally, one can line the outside walls/sides of the excavated leach pit or drain lines to keep soil from migrating into the gravel from sides. 
This sidewall protection is always recommended when soils are loose or sandy and would otherwise tend to wash soil into the gravel. Geotextile fabric is also used for wrapping perforated pipe-in-gravel French drains, as pictured below, with fabric on the bottom of trench too. French drains are wrapped like a burrito, unlike septic leach field lines where the fabric is on the top and sides only. Protecting your leach pit and perforated pipe gravel from soil and root infiltration is crucial to long-term soil percolation and preventing leach field failure.

main septic system design chapter with complete list of products & pricing