HomeMy WebLinkAboutBERGH S12553Onsite File
Eklutna Engineering, LLC
curtistownsend@gmail.com
November 10, 2020
Subject: Soils investigation report and well/septic reserve area for the proposed subdivision of
Sue Tawn Estate #2 Block 1 Tract A
Subdivision Case # S12553
On -Site Permit Number OSP201392
Ms. Wockenfuss,
Sue Tawn Estate #2 Block 1 Tract A is located in Chugiak Alaska. Based on the preliminary plat drawing
provided to us, the subdivision of Tract A will consist of two lots. We have excavated and logged test
holes on each proposed lot that will be used to establish septic reserve areas or platted drainfields for
each lot in the subdivision.
It should also be noted that permit OSP201392 has been approved for the installation of septic fields
and a water well for these two lots. The approved permit is attached to show the septic site plan,
locations of test holes and soil logs. It also shows neighboring well radii and slopes of grades in the area.
PROPOSED WELL AND SEPTIC RESERVE AREAS
We have prepared soil logs for all the test holes (see attached). Per MOA wastewater ordinance AMC
15.65.410, we are required to provide a site map showing a septic reserve area for each lot that meets
the requirements set forth in Table 7. Both test holes show a percolation rate in the range of 1— 5 mpi.
Based on table 7, each lot would require a septic reserve area of 10,000 square feet. As can be seen on
the site map, much of the property has steep slopes except for those areas that have been graded for
building construction. OSP201392 permits the construction of the septic fields and reserve areas on
these graded areas. There is sufficient room to provide for proposed and reserve septic systems.
WATER AVAILABILITY
A 6" water well has been drilled on this property summer 2020 to a depth of 265'. The well log is
attached. As can be seen, this well has a recovery rate of 50 gpm. Surrounding properties already have
wells in place. Let's consider water flow and nitrate levels for each of the developed lots surrounding
this property.
Sleepy Hollow Subdivision No. 1 Block 1 Lot 1 The well on this property was drilled in 2016 to a depth of
400' and it has a recovery rate of 0.72 gpm. No nitrate sampling results are available for this property.
Sleepy Hollow Subdivision No. 1 Block 1 Lot 2 The well on this property was drilled in 2002 to a depth of
217' and it has a recovery rate of 2 gpm. It was last tested for nitrates at a concentration of 3.38 mg/L in
2012.
Sue Tawn Estate #2 Block 1 Lot 10 There is no well log for this property. In 2017 the nitrate levels were
1.87 mg/L and the well produced 2 gpm as tested at the house.
Page 1 of 2
Subdivision of Sue Tawn Estate #2 Block 1 Tract A Case #512553
Sue Tawn Estate #2 Block 1 Lot 14 The well on this property was drilled in 1992 to a depth of 233' and
has a recovery rate of 30 gpm. It was last tested for nitrates in 1993 at a concentration of 1.29 mg/L.
Sue Tawn Estate #2 Block 1 Lot 8 There is no well log for this property. In 2018, nitrate levels measured
2.51 mg/L and the well produced 4 gpm as tested at the house.
Water is sufficiently available in this area. Nitrate levels are not exceedingly high. The subdivision of
Tract A will not adversely affect water availability and nitrate levels in this area.
The proposed subdivision will not affect the future development of this or the surrounding lots.
Sincerely,
Curtis L. Townsend, P.E.
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Page 2 of 2
Subdivision of Sue Tawn Estate #2 Block 1 Tract A Case #S12553
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