PROJECT BRIEFING Benedict Central Sewer System
Transcript of PROJECT BRIEFING Benedict Central Sewer System
PROJECT BRIEFING
Benedict Central Sewer System
September 11, 2012
BENEDICT CENTRAL SEWER SYSTEM PROJECT OVERVIEW
• Project Purpose: To design and construct a centralized
wastewater collection, treatment, and disposal system to
replace all individual on-site septic systems with a public
sewer system.
• There are 209 developable lots, of which, 123 or 58.8% are
developed.
• In the mid-80’s a public water system was installed due to the
contamination of wells by nitrates from septic systems.
(Source: Charles County Health Dept.).
• Feasibility Study completed in 2004 by Wallace Montgomery
& Associates (WMA) to identify and evaluate alternatives for
sanitary sewerage collection, treatment, and disposal.
• Project Design began in February of 2009.
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2 mi.
BENEDICT CENTRAL SEWER SYSTEM CONCEPTUAL LAYOUT
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BENEDICT CENTRAL SEWER SYSTEM CONCEPTUAL LAYOUT
• DISPOSAL SITE AREA
BENEDICT CENTRAL SEWER SYSTEM DISCHARGE OPTIONS
1. Surface Water Discharge
(Denied by MDE - Shellfish Harvesting Designation for the
Patuxent River).
2. Effluent re-use by Chalk Point Power Plant (Insufficient
Flow to meet needs).
3. Land Application (further investigation):
• Rapid Infiltration
• Large On-Site Disposal System
• Slow Rate Infiltration (Spray/Drip Irrigation)
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Criteria:
• Land Area:
• 0.29 ac. to 5.84 ac.
• Soils:
• 10 feet of separation from groundwater
• Well to excessively drained soils; sandy loam to
sand (2 to 20 inches/hour permeability)
Based on a Web Soil Survey Analysis it was determined that
finding a site with favorable conditions would be very difficult in
Charles County within 6 miles.
BENEDICT CENTRAL SEWER SYSTEM DISCHARGE OPTIONS
LAND APPLICATION – RAPID INFILTRATION
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BENEDICT CENTRAL SEWER SYSTEM DISCHARGE OPTIONS
LAND APPLICATION – LARGE ON-SITE DISPOSAL
Criteria:
• Land Area:
• 25 to 37 acres (based on the highest permitted
loading rate of 1.2 gallons/square foot
• Soils
• 4 feet of separation from groundwater
• Well Drained Soils
• Uniform Soil Material is ideal
MDE suggested that locating 25 to 35 acres that will allow a
uniform loading rate 1.2 gals/sq. ft. will likely be very difficult.
Therefore, this option was excluded from further consideration.
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BENEDICT CENTRAL SEWER SYSTEM DISCHARGE OPTIONS
LAND APPLICATION – SLOW RATE INFILTRATION
Criteria:
• Land Area:
• Spray: 17 – 294 ac.
• Drip: 24 – 468 ac.
• Soils:
• 4 feet of separation from groundwater
• Moderately well to excessively well drained soils
(0.2 to 6 inches/hour permeability)
This option was used as the basis for site selection.
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BENEDICT CENTRAL SEWER SYSTEM DISCHARGE SITE SELECTION
Query Results (40+ acres within 3 miles of Benedict)
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BENEDICT CENTRAL SEWER SYSTEM DISCHARGE SITE SELECTION
Query Results/Usable Acreage Analysis
• Most Favorable
• Favorable
• Least Favorable
• Sites Eliminated from Search
• 1, 2, & 4 – Steep Slopes
• 6 – Under Development
• 7 – Marsh Land
• 9, 12, & 13 – DNR Property
• 14 – Small Usable Area
• 15 – Ag. Preservation
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• Preliminary site testing performed on Amberleigh Farms.
• As a backup plan, expand search to include sites of 10 - 40 acres
(multiple disposal sites).
• 15 additional sites were selected.
• Letters of Interest mailed to 19 property owners.
• Received 10 responses; (9) positive, (1) negative, and (1) returned
undeliverable.
• Of 9 properties that provided positive responses, 4 properties
were selected for preliminary soils testing by Health Dept. (all
found favorable). Backup plan in place.
BENEDICT CENTRAL SEWER SYSTEM DISCHARGE SITE SELECTION
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• Hydrogeological Study initiated for Amberleigh Farms property in
April 2010.
• Study completed October 2010.
• Study Results:
• Site is most sufficient for spray irrigation
• Site insufficient for drip irrigation, trench, sand mound, and
rapid infiltration systems
• Minimum required area = 21.2 acres
• Site Disposal capacity = 62,160 gpd (design flow is 58,863 gpd)
BENEDICT CENTRAL SEWER SYSTEM DISCHARGE SITE SELECTION
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BENEDICT CENTRAL SEWER SYSTEM DISCHARGE PERMIT APPLICATION
• Groundwater Discharge Permit Application submitted to MDE
in June 2011.
• Public Notice of permit advertised by MDE on March 7th and
again on March 14th of 2012.
• Public Hearing requested.
• Public Hearing held on May 23, 2012.
• 2nd Public Hearing held on June 26, 2012.
• Permit issuance pending environmental site assessment.
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• Collection System (Gravity): $2,283,722
• Treatment System: $3,393,605
• Disposal System & Force Main: $3,265,544
TOTAL = $8,942,871
Cost/Developed Property (123) = $72,706
Cost/Property (209) = $42,788
Original Cost Estimate : $3,243,412
Cost/Existing Resident (123) = $26,369
Cost/Property (233) = $13,920
BENEDICT CENTRAL SEWER SYSTEM CONSTRUCTION COST ANALYSIS
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BENEDICT CENTRAL SEWER SYSTEM FISCAL NOTE
• Current Construction Budget = $3,234,000
• Future Funding:
• FY14: $1,210,000
• FY15: $2,956,000
• Total Construction Funding: $7,400,000
• Additional funding needed = $1.5M
• Est. property acquisition costs = $430,000
• Current ROW Budget: $100,635
• Additional ROW funding needed = $330,000
• Total additional project funding needed = $1.83M
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Presented by:
Charles County Government
Planning & Growth Management Peter Aluotto, Director
200 Baltimore Street, La Plata, MD 20646
301-645-0641
E-mail: [email protected]
www.CharlesCountyMD.gov
Mission Statement
The mission of Charles County Government is to
provide our citizens the highest quality service
possible in a timely, efficient, and courteous
manner. To achieve this goal, our government must
be operated in an open and accessible atmosphere,
be based on comprehensive long- and short-term
planning, and have an appropriate managerial
organization tempered by fiscal responsibility.
We support and encourage efforts to grow a
diverse workplace.
Vision Statement
Charles County is a place where all people thrive
and businesses grow and prosper; where the
preservation of our heritage and environment is
paramount, where government services to its
citizens are provided at the highest level of
excellence; and where the quality of life is
the best in the nation.