pressure mound system: septic installers - mike schwartz, p.e
TRANSCRIPT
PRESSURE MOUND SYSTEM TIMED DOSE Michael A. Schwartz, [email protected]
Changing Regulations
New Kalamazoo County Sanitary Code Kalamazoo County Health & Community Services New in December 2007 Restrictions now include properties:
Where a public sewer is available to the property. Where the proposed location of a septic tank would render the
septic tank inaccessible for cleaning or inspection purposes. Where the property to be served by the onsite sewage
treatment system is too small to allow for proper isolation distances between the onsite sewage treatment system which includes the replacement area and any existing or proposed water wells, or surface waters.
Changing Regulations
New Kalamazoo County Sanitary Code Restrictions now include properties:
Where the property lacks sufficient drainage area and/or replacement area.
Where the property’s high groundwater and/or mottling is 24 inches or less of the natural ground surface elevation for installation of an onsite sewage treatment system on new construction sites.
Where the property’s stabilized percolation rate exceeds 60 minutes per inch.
Where the Department determines that the property’s soil classification and/or physical conditions are unsatisfactory for the treatment of sewage effluent.
Changing Regulations
New Kalamazoo County Sanitary Code Restrictions now include properties:
Where conditions exist upon the property, or may occur upon the property, which may endanger the public health or the environment.
Where the proposed site is subject to flooding and/or is included within the 100-year flood plain.
Changing Regulations
Appeals Board Engineered Alternative System required Not every site has the space and porous soil needed
to support a septic system. If an alternative system is required it will be: More Costly Ongoing Maintenance Yearly Inspections Engineered System
Denial of Permits: The Big 3
Lack of Land Area Poor Soils Seasonal High Water Table (<24”)
Denial of Permits: The Big 3
Lack of Land Area Potential Problems:
Treatment (strength of waste) Hydraulic Issue (drain field size) Both
Denial of Permits: The Big 3
Poor Soils Percolation: Soils drain too fast
Problem: treatment leaving the septic tank Solution: treatment system in conjunction with septic tank Example: Re-Circulating Sand Filter
Sample Design Sand Filter
Advantex Treatment System
Re-Circulating Sand Filter
Denial of Permits: The Big 3
Poor Soils Percolation: Soils drain too fast
Problem: treatment leaving the septic tank Solution: treatment system in conjunction with septic tank Example: Re-Circulating Sand Filter
Percolation: Soils drain too slow Problem: Hydraulic disposal of effluent leaving septic tank Treatment: System to reduce particles to soils would be
beneficial Solution: Larger drain field
Denial of Permits: The Big 3
Seasonal High Water Table (<24”) Potential Problems:
Treatment (strength of waste) Hydraulic Issue (drain field size) Both
Must get oxygen into the treatment system (drain field)
Solution: Mound System
Sample Design Mound
Mound System for High Water Table
Denial of Permits: The Big 3
Seasonal High Water Table (<24”) Potential Problems Must get oxygen into the treatment system (drain
field) Solution: Mound System
“Pump and Dump” 4” Laterals – Gravity Feed
Pressure Distribution Small Laterals – Pressurized “Pump & Dump” Timed Dose
This is what we want to avoid!
COOPER TOWNSHIPCase Study #1
Case Study: Cooper Township
1st One Built, 2nd One Permitted Issue for Denial Water Table within 24” of Ground Surface Suitable Soils Solution: Pressure Distribution Mound with Timed
Dose
COOPER TOWNSHIPPre-Construction
Beginning construction of the house. The septic tanks and pump chamber will be set on the existing ground and the proposed grade will be built around the system.
Another view of where the system will be constructed, immediately in front of the house. The bottom of the basement is basically at the elevation of the existing ground.
Area in front of the house where the base of the mound (absorption system) will be installed upon.
COOPER TOWNSHIPConstruction
The site has been rough graded (area around building is filled). Contractor is excavating to install the septic tank.
Contractor installed the septic tank. Pipe sticking out is the discharge to the pump chamber.
Contractor is on the septic tank and the installed pump chamber is on the right.
The force main from the pump chamber to the new drain field. Note since the system is a pumped system it is very flexible in the configuration and field installation. The piping will go around the tanks to avoid and other utility conflicts.
Continuation of the forcemain. Pump chamber is on the left and the septic tank is on the right.
2NS sand fill for the soil absorption system. This is the layer the stone will be placed upon.
Looking at the 100’ long drainfield. Standing at approximately where the header pipe will be installed.
Rough grading around the drainfield prior to placing the stone.
Very rough grading above tanks
Header pipe on top of the newly installed stone.
Looking at the 100’ pressure distribution laterals within the new drainbed. Pipe about half way down is the observation port.
Looking at the 100’ pressure distribution laterals within the new drainbed. Pipe about half way down is the observation port. The orifice shield are removed from the up-holes to testing of the system. There is a down-hole in between each of the up-holes.
Looking at the 100’ pressure distribution laterals within the new drainbed. Pipe about half way down is the observation port. The orifice shield are removed from the up-holes to testing of the system. There is a down-hole in between each of the up-holes.
Contractor waiting for the pump chamber to fill with water to test the system.
Pump is activated and “squirt” test is performed.
Health Department personnel verifying squirt test.
Orifice shield place back over the up-holes.
Contractor installing the fabric prior to covering the system.
Contractor installed fabric prior to covering the system and placing final fill over the system
Contractor placing final cover over system
Contractor placing final cover over system
Existing site behind the new mound. Pipe is the downspout from the roof that is directed away from the system.
Contractor placing final cover over system
Inside the new control panel
COOPER TOWNSHIPPost-Construction
Post-Construction
Post-Construction
What did we learn?
Pre-Construction meetings can answer a lot of questions.
The system can perform (squirt test) as the math and calculations show should occur.
Pump Systems are very flexible in design and configuration.
Multiple arrangement of float configurations are possible (2 floats, 3 floats, 4 floats).
Health Department is there to help and to make sure it will be a “good” system.
ALAMO TOWNSHIPCase Study #2
Case Study: Alamo Township
1st One Permitted, 2nd One Built Issue for Denial Water Table within 24” of Ground Surface Suitable Soils Solution: Pressure Distribution Mound with Timed
Dose
Case Study: Alamo Township
Case Study: Alamo Township
Mound prior to seeding.
Squirt test being performed. No one was present during construction, so the contractor had to dig and expose the first and last orifice to perform a squirt test.
Squirt Test being performed.
Rough grades around the tanks (septic tank and pump chamber). The open lid is the pump chamber.
Looking inside the riser of the pump chamber.
Some final site photos a few weeks after new system was installed.
Some final site photos a few weeks after new system was installed.
What did we learn?
Contractor – have a preconstruction meeting Contractor – Follow what the KCHSD permitted for
the system Contractor – Follow what is specified (soils) per
the codes and drawings If Not – you will start over It will cost the Contractor $$$
