Avlarson, the plastic chamber leach field material such as Infiltrators, ADS Bio-Diffusers, or Cultecs Contactors are excellent alternatives to pipe and stone leach fields. Gravelless leach field material is a vast improvement over the old “stone age” technology.
One word of caution regarding the issue of siltation, or soil migration into the void provided by the chambers. I recommend that a layer of 6 ounce geotextile fabric be placed over the top of the chamber units. A 4 foot wide sheet fits perfectly to cover the louvers on the side of units to prevent siltation, and the fabric also aids in wicking the effluent to the top of the chamber, and then into the soil.
I also recommend that an alternating leach field be installed. Each leach field should contain 50% of the required leach field area, or number of chamber units. A 4 inch diversion valve, manufactured by National Diversified Sales, is placed in the septic tank effluent pipeline so that the effluent flow can be alternated on an annual basis. Also, monitoring and ventilation ports should be installed on the ends of each leach field. If you require more direction on this design, send me an e-mail message. Click on the profile icon at the bottom of this message for the address. JWA