HomeMy WebLinkAbout1982-06-01 Memo, Septic System Design Review$
EXHIBIT
TO:
FROM:
DATE:
Jeanne A. Mabusth, Zoning Administrator
Michael P. Gaffron, Septic System Inspector
June 1, 1982
SUBJECT; #685 Charles Krogness - Subdivision - Septic System Review
I have reviewed the proposed subdivision and wish to make the
following comments:
Lot 1 (new lot) - Primary and alternate sites were tested,
with percolation rates averaging 7.4 and 5.7 mpi respectively.
Water table depth ranged from 3.7 ft to 5.8 ft or deeper,
hence shallow trenches would be recommended, as well as runoff
and groundwater diversions uphill from the system, assuming
house location does not change.
Lot 2 - Existing house with existing system. Existing system
was inspected in 1981 and appeared to be in operable condition.
An alternate site has been tested and is suitable for a standard
drainfield. One problem does present itself, however. At
least one drainfield line protrudes approximately 15-20' into
the proposed new lot at a point where the new house would presumably
be located. Orono code requires a 20' setback for drainfield
from property lines, although only 10' is normally enforced
where reasonable to do so. For this subdivision, since the
existing drainfield would be very close to the proposed new
house, two options present themselves:
1 - Rearrange lot lines to give the 10' setback. This would
severely limit the area where the proposed house could
be located.
2 - Cut off the existing drainfield to a point at least 10'
back from the proposed lot line, then add an equivalent
amount of drainfield downhill on Lot 2. While it may
seem unreasonable to remove an existing functional
drainfield becuase it is over the lot line, it is equally
unreasonable to expect a future owner of Lot 1 to allow
treatment of his neighbors sewage on his lot. Futhermore,
the expected runoff from a house on Lot 1, as well as
construction fill and disturbance, might possibly disrupt
the proper functioning of that portion of drainfield anyway.
One problem that may crop up is that by cutting off the end
of the drainfield, the soil disturbance may create a seepage
point if the line fills up.
My recommendation is that the entire line (or lines) be abandoned
and the equivalent or more of new drainfield be constructed further
south, .where the effect of added runoff will be lessened.
(While allowing the lines to be merely shortened would be acceptable
if we knew Mr. Krogness would continue to own the existing house,
we should not take the chance that drainfield changes made
necessary by the subdivision cause a future problem for a new
owner of the existing house).