Analysis
of Monitoring Results of the Separation and Greywater Treatment
System at Chester Woods Park, Olmsted County, Minn.
March
25, 1998
Terry
Lee, Kimm Crawford, and Tony Hill
Olmsted
County Water Resources Center
2116
Campus Drive SE, Rochester, MN 55904
Introduction
In
1993, Olmsted County installed an advanced individual sewage
treatment system (ISTS) at the caretaker's residence at a County-owned
park to demonstrate waste load reduction and downsizing of drainfield
area. The subject system has two components--1) a composting/vermiculture
blackwater system and a 2) aerobic graywater treatment system.
The separation of the high strength human feces and urine from
other wastewater generated by the household is the key feature
of this system. Kitchen food wastes are processed in the BMRC
(Bio-Matter Re-Sequencing Converter), while sink, bath, dishwasher,
and clothes washing wastewaters are handled in the aerobic graywater
system. As part of the demonstration, monitoring was conducted
for a range of chemical and physical wastewater parameters,
as well as for water, electric, and drainfield use. Test results
indicate that the system is operating as expected with regards
to effluent nitrogen, organics, and fecal coliform levels, as
well as electrical use, airflow, and drain-field use.
Summary
and Conclusions
Based
on the monitoring data and on characteristics of typical untreated
domestic wastewater, the system is calculated to have achieved
a 90% or greater reduction in loadings of total nitrogen, BOD,
and suspended solids to the drainfield. Fecal coliform levels
are calculated to be up to 1,000 fold less than effluent from
conventional septic tank effluent. Measured water use, measured
pollutant loadings, and the lack of ponding in drainfield trenches,
are consistent with the original design of a 40% downsized soil
treatment area. Drainfield use in the first four years of operation
is consistent with a projected life expectancy of at least 20-25
years. The volume of compost accumulated since commissioning
the unit is consistent with the vendors' projection. This material
will need to be removed from the unit within the next year and
a new charge of bulking material will be necessary. Best management
practices for finished compost will be determined based on further
compost testing. Currently, the handling of this material is
covered by the septage and biosolid rules MN Statutes 7040.
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Sustainable
Wastewater Separation Treatment Systems Coupled with Nutrient
and Water Reducing Greywater Reuse Technologies
D.
G. Brauer, P.E., K. W. Crawford, C. R. Elston, R. J. Elston,
P. J. Gillen, T. Hill, T. A. Lee, M. R. Pollen*
Abstract
Nationally
and internationally, pressure is increasing to introduce nutrient
reducing, water conserving and recycling measures for sustainable
residential and small community water/wastewater systems. Reports
of inadequate water quality and quantity are being reported
daily. Over the past thirty years the federal government and
State of Alaska have invested over 4 billion dollars installing
piped water and sewer systems in remote Native Alaskan Bush
Villages (averaging over $80,000 per household) with a ninety
percent failure rate because of the high operation, maintenance
and replacement costs. In Minnesota alone it is estimated that
$1.8 billions dollars is required to upgrade existing community
sewer and onsite septic systems. At the World Summit on Sustainability,
United Nations, World Bank and certain key professionals stated
that the current way in which wastewater is handled in the developed
world is probably not sustainable, and hence the technologies
in use are, in their present form, not appropriate for transfer
to the developing world.
Systems
utilizing separation technology represent a logical option for
reducing and eliminating these pressures. Northern Testing Laboratories,
Inc., the University of Alaska Fairbanks (Fairbanks, AK) and
the Olmsted County Water Resources Center (Rochester, MN) have
tested and documented that the Equaris BMRC (BioMatter ReSequencing
Converter) and Greywater Treatment Systems can reduce water
consumption by 40%, CBOD & TSS by 90%, nitrates by 99% and
bacteria by 1000 fold when compared to septic tank effluent.
The further treated, filtered and disinfected greywater effluent
for reuse either within the household or for safe discharge
to ground or surface water is possible with the use of the Household
Water and Wastewater Treatment and Recycling System. This type
of sustainable technology has the capability of eliminating
the need for sewer collection systems by reducing water usage
and pollution loading to levels sufficient and acceptable for
onsite disposal with dramatically reduced subsurface absorption
system sizing. Total recycle of wastewater is possible with
far reaching implications for sustainable development, conservation
of water, protection of the environment, lakes and groundwater
in particular, building on difficult lots, urban sprawl and
annexation.
Financing of water conserving and pollution preventing wastewater
systems for homes and small communities is available through
the commercial banking system associated with this technology.
To provide incentive to the wastewater treatment industry and
the public, legislation has been introduced in the State of
Minnesota, which, if passed, will provide zero interest loans
for wastewater treatment technologies other than standard that
can reduce water consumption and pollution.
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