HomeMy WebLinkAboutEngineering NewsletterMunicipality of Anchorage
Department of Health and Human Services
ENGINEERING NEWSLETTER Vol. II, No. I
February 4, 1986
REQUIREMENTS FOR NEW PERMITS FOR WELLS AND SEPTIC SYSTEMS
Effective March 1, 1986 all permits for new septic systems should include:
1. A soils test performed within ten feet of the proposed wastewater dis-
posal field. A second soils test for the replacement site may be
required if there is some question about the availability of a replace-
ment site on the lot.
2. Groundwater monitoring on each test hole. A minimum of seven days of
monitoring is required. The Department reserves the right to
reject water level measurements if they do not reflect the seasonal high
water level. Alternatively, a suitable "adjustment factor" may be
applied to monitored levels to account for seasonal fluctuations.
3. A scaled site plan, stamped by a registered engineer showing the
fo owing:
a. The original and at least one replacement disposal site. The pro-
posed systems must be drawn to scale.
b. The proposed well location.
c. The location of all adjacent water and sewer systems located within
'LOU feet of the proposed well and septic system.
d. The location and extent of curtain drains and surface water flows
and standing water areas whether permanent or intermittent.
e. Slope evaluation. Show general slope of terrain. Indicate areas of
slope exceeding 25%.
This site plan should be submitted on a 81&" x 11" sheet. A sample site plan has
been enclosed with this newsletter.
REQUIREMENTS FOR UPGRADE PERMITS
All upgrade permit applications must include a site plan containing the same
information required for a new permit. A soils test and water monitoring will
be required for an upgrade permit. The application need not show that an addi-
tional replacement site exists on the lot. This applies to upgrades only.
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CURTAIN DRAIN DESIGN REQUIREMENTS
Effective March 1, 1986, the Department will require that detailed plans for
ro�' all curtain drains proposed for lots with on-site wastewater disposal be sub-
mitted for plan review. In addition, any known curtain drain should be included
in the as -built drawing if it is constructed within 100 feet of the septic
system.
The engineer should demonstrate the effectiveness of a new curtain drain by
monitoring groundwater levels upstream and downstream of the curtain drain.
Alternatively, water levels in a test hole downstream of the curtain drain and
in the vicinity of he area intended for wastewater disposal can be monitored
before and after the curtain drain installation to demonstrate the drain's
ability to lower the water table.
A permit for an on-site system will not be issued until the curtain drain's
effectiveness has been established.
LIFT STATION DESIGN REQUIREMENTS
Effective March 1, 1986, all lift station installations will be subjected to
more thorough review by the Department. Engineers must submit detailed plans
for lift stations for review prior to installation. These plans should include:
1. A drawing showing the dimensions and capacity of the lift station tank.
This drawing should show the specific level of the "pump on", "pump off",
and high water alarm.
2. Construction materials, manufacturing and insulation details should be
indicated where appropriate. Corrosion protection is required and
should be specified.
3. The make and model of the pump should be noted. Show that the pump is
adequately sized.
4. Show that electrical controls are adequately protected from corrosive
environments and/or weather.
5. The engineer should demonstrate:
a. Dosing volume is approximately 25 percent of the average daily
wastewater flow.
b. A minimum 150 gallons of reserve capacity is provided above the high
water alarm.
6. The high water alarm should be located inside the house and should be on
a circuit separate from the pump.
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