Constructed Wetlands...

General Site Design...

Application : Constructed wetlands shall only be used where soil percolation rates at the site exceed 120 minutes per inch. Because of the higher maintenance requirements of constructed wetland systems, preference should be given to sand filters, where conditions allow.
Effluent treatment : The effluent from a constructed wetland shall receive additional treatment through the use of intermittent sand filters of a magnitude of half.
Effluent sampling : Effluent sampling of constructed wetlands shall be performed twice a year or as directed by the administrative authority. Tests shall be run on all parameters.
Other info : Specifications given in these rules for constructed wetlands are minimum and may not be sufficient for all applications. Technical specifications are changing with experience and research. Other design information beyond the scope of these rules may be necessary to properly design a constructed wetland system.

Wetland Design...

Depth : The wetland shall be of a subsurface flow construction with a rock depth of 18 inches and a liquid depth of 12 inches.
Materials : Substrate shall be washed river gravel with a diameter of ¾ inch to 2½ inches.
Sizing and configuration : Detention time shall be a minimum of seven days.
Dimensions : This may be accomplished with trenches 16 to 18 inches deep (12 inches of liquid), 3 feet wide with 100 feet of length per bedroom. This may also be done with beds 16 to 18 inches deep with at least 300 square feet of surface area per bedroom. The bottom of each trench or bed must be level within + or – ½ inch.
Configuration : Multiple trenches or beds in series should be used. Beds or trenches in series may be stepped down in elevation to fit a hillside application. If the system is on one elevation, it should stiff be divided into units by earthen berms at about 50 and 75 percent of the total length.
Unit connections : Each subunit shall be connected to the next with an overflow pipe (rigid sewer pipe) that maintains the water level in the first section. Protection from freezing may be necessary.
Liner : Wetlands shall be lined with a synthetic PVC or PE plastic liner 20 to 30 mils thick.
Inlet pipe : Effluent shall enter the wetland by a 4-inch pipe sealed into the liner. With beds, a header pipe shall be installed along the inlet side to distribute the waste.
Protective berms : Wetland system sites shall be bermed to prevent surface water from entering the trenches or beds.

Vegetation...

Setting plants : Vegetation shall be established on the wetlands at time of construction. Twelve inches of rock is placed in each unit, the plants are set, then the final 4 to 6 inches of rock is placed.
Plant species : Only indigenous plant species shall be used, preferably collected within a 100-mile radius of the site. Multiple species in each system are recommended. Preferred species include, but are not limited to ;

1. Typha Latifoha - Common cattail
2. Typha Angustifolia - Narrow leaf cattail
3. Scirpus spp. - Bullrush
4. Phragniites communis – Reed

Plant establishment : Transplantation is the recommended method of vegetation establishment. For transplanting, the propagule should be transplanted, at a minimum, on a 2-foot grid. The transplants should be fertilized, preferably with a controlled release fertilizer. such as Osmocote 18-5-11 for fall and winter planting, 18-6-12 for spring planting, and 19-6-12 for summer planting. Trenches or beds should be filled with fresh water immediately.
Plant management : In the late fall the vegetation shall be mown and the detritus left on the wetland surface as a temperature mulch. In the early spring the mulch shall be removed and disposed of to allow for adequate bed aeration.

Click here for more info about "Design Procedure"...

Disposal of Septage from On - Site Wastewater Treatment and Disposal Systems...

Methods of Septage Disposal...

(a) Discharge (with owner approval) to a municipal or other permitted wastewater treatment system.
(b) Discharge (with owner approval) to permitted sludge lagoons or sludge drying beds.
(c) Land application in accordance with the following requirements :
(1) The maximum application rate is 30,000 gallons of septage per 365-day period per acre of cropland.
(2) The following site restrictions shall be met when septage is applied to land :
(2 - 1) Septage shall not be applied to a lawn or a home garden.
(2 - 2) The septage shall be applied only to soils classified as acceptable throughout the top five feet of soil profile. The septage shall not be applied to soils classified as sand, loamy sand and silt. The acceptability of a soil shall be determined using the USDA soil classifications.
(2 - 3) Land application sites shall have soil pH maintained above 6.0, unless crops prefer soils with lower pH conditions. If the soil pH is below 6.0, it is acceptable to use agricultural lime to increase the pH to an acceptable level.
(2 - 4) If the septage is applied to land on which the soil loss exceeds the soil loss limits established by the county soil conservation district, the septage shall be injected on the contour or shall be applied to the surface and mechanically incorporated into soil within 48 hours of application. The septage shall not be applied to ground having greater than 9 percent slope.
(2 - 5) Septage application on frozen or snow-covered ground should be avoided, unless special precautions are taken to avoid runoff. If application on frozen or snow covered ground is necessary, it shall be limited to land areas of less than 5 percent slope.
(2 - 6) Septage shall not be applied to land that is 35 feet or less from an open waterway. If septage is applied within 200 feet of a stream, lake, sinkhole or tile line surface intake located down gradient of the land application site, it shall be injected or applied to the surface and mechanically incorporated into the soil within 48 hours of application.
(2 - 7) If the septage is applied to land subject to flooding more frequently than once in ten years, the septage shall be injected or shall be applied to the surface and mechanically incorporated into the soil within 48 hours. Information on which land is subject to flooding more frequently than once in ten years is available from the department.
(2 - 8) Septage shall not be applied within 200 feet of an occupied residence or within 500 feet of a well.
(2 - 9) Food crops shall not be harvested for 3 8 months after application of septage.
(2 - 10) Animals shall not be allowed to graze on the land for 30 days after application of septage.
(3) One of the following vector attraction reduction and pathogen reduction requirements shall be met when septage is applied to land :
(3 - 1) Septage shall be injected below the surface of the land. No significant amount of the septage shall be present on the land surface within one hour after the septage is injected.
(3 - 2) Septage applied to the land surface shall be incorporated into the soil within six hours after application to or placement on the land.
(3 - 3) The septage shall be stabilized by adding and thoroughly mixing sufficient lime to produce a mixture with a pH of 12. Provide a minimum of two hours of contact time after mixing the lime with the septage prior to applying to land. Each container of septage shall be monitored for compliance.
(3 - 4) The septage shall be stabilized by adding and thoroughly mixing 50 pounds of lime with each 1,000 gallons of septage.
(4) When septage is applied to land, the person who applies the septage shall develop the following information and shall retain the information for five years :
(4 - 1) The location, by either street address or latitude and longitude, of each site on which septage is applied.
(4 - 2) The number of acres in each site on which septage is applied.
(4 - 3) The date and time septage is applied to each site.
(4 - 4) The rate, in gallons per acre per 365-day period, at which septage is applied to each site.
(4 - 5) A description of how the vector attraction reduction requirements are met.
(4 - 6) The following certification statement shall be provided with the records when the records are requested by the department :

"I certify, under penalty of law, that the pathogen requirements and the vector attraction reduction requirements have been met. I am aware that there are significant penalties for false certification including the possibility of fine and imprisonment."

(5) Other methods of stabilization may be acceptable if shown to be equivalent to 69.17(l) c (3) 3.
(d) Discharge (with owner approval) to a permitted sanitary landfill in accordance with 567-Chapters 102 and 103 and the following requirements :
(1) Stabilize the septage by adding and thoroughly mixing sufficient lime to produce a mixture with a pH of 12.
(2) Provide a minimum of two hours of contact time after mixing the lime with the septage prior to applying to the landfill.
(3) Dewater the septage.
(4) Obtain a special waste authorization permit from the department.