Groundwater in the Great Lakes Basin

Table 3.
Washtenaw County, Michigan, Time of Sale – Historical Comparisons.
Year Number of Evaluations Percent Failure
2003 807 18
2002 881 20
Overall 3,451 17
Table 4.
Wayne County, Michigan, Transfer Evaluation Summary,
February 2000 - December 2003.
Year
Number of
Evaluations
Number of
Failures
2000 108 22 20.37
2001 100 32 32.0
2002 121 31 25.6
2003 112 31 22.67
Total 441 116 26.30
Percent Failure
Washtenaw County, Michigan, time-of-sale records
reveal that of the 3,451 evaluations since 2000 17% of
septic systems had failures of some type (Table 3). A
Wayne County, Michigan, transfer evaluation summary
from February 2000 to December 2003 shows that of
441 evaluations there were 116 failures (Table 4). The
number of failures is increasing as the number of U.S.
systems older than their 30-year life span continues
to increase (Gorman, personal communication).
Considering the large number of septic systems in
the Great Lakes region, the potential for widespread
groundwater contamination is immense.
In some communities authorities are offering grants to
upgrade septic systems. For example, the Essex Region
Conservation Authority (ERCA) is offering grants of
up to $5,000 (ERCA, 2008; “ERCA offers,” 2008). There
are an estimated 12,000 faulty septic systems in the
Essex County, Ontario, region (“Clean water,” 2006). In
the nearby community of Lakeshore faulty septic tanks
from 400 homes in the community are believed to be
the main cause of water pollution contaminating Lake
St. Clair (Rennie, 2006).
Other undertakings include a $400,000 supplemental
environmental project by Fort Wayne, Indiana, to
eliminate failing septic systems (USEPA, 2007).
FAILURE PREVENTION – REGULAR
MAINTENANCE AND BACKWASH FLUSHING
Careful landscaping of the soil absorption bed, awareness
of inputs (e.g., wastes disposed in sinks, garbage
disposals and toilets should be easy to break down)
and regular pumping, maintenance and upgrades will
prolong septic tank life (Septic Tanks, 2004; Veritec
Consulting, 2004; Manitoba Conservation, 2006). A
typical family will discharge enough material fibers
or lint down the drain to carpet a living room every
year. These fibers are a major cause of clogged pipes or
plugged absorption bed soil, causing septic systems to
fail (Septic Tanks, 2004). Garbage disposal systems are
also extremely hard on septic systems (Rafter, 2005). To
prevent failures, septic tank pumping frequency should
be based on tank capacity and household size (Table 5).
A study by Veritec Consulting (2004), commissioned
by Manitoba Conservation (2006), was designed to
provide information to assist homeowners installing
septic fields to more appropriately size their absorption
fields and to identify options to reduce wastewater
load. Veritec concluded that reducing the flow of
wastewater through the septic tank by installing
water conserving fixtures (e.g., low-flush toilets and
dual-flush technology, front-loading clothes washers
and low-flow shower heads), spacing out water use
throughout the day of week (i.e., avoid doing all
laundry on one day) and keeping fixtures in good repair
can help prolong septic life. See http://www.gov.mb.ca/
conservation/envprograms/wastewater/maintenance/
index.html. The reduction allowed time for solids to
61