Upload
others
View
4
Download
0
Embed Size (px)
Citation preview
WATER TREATMENT PLANT PROJECT
Gregory KromJune 2017
Project Overview
• Why is it needed?• What does the project entail?• What is the cost?• Water rate impacts?• Benefits?
Friday, June 16, 2017 2
WHY DO WE NEED A TREATMENT PLANT?
Friday, June 16, 2017 3
Manganese
• Historically an aesthetic issue– 5 parts per billion (ppb) to avoid staining
• Regulated by MassDEP due to potential health effects– 300 ppb for lifetime of healthy adult– 300 ppb for children, infants for 10 days– 1000 ppb for 10 days for health adult
Friday, June 16, 2017 4
0.050 0.100 0.200 0.300 0.500 0.750 1.000 MoreFrequency 11 45 67 37 31 0 0 1Cumulative % 6% 29% 64% 83% 99% 99% 99% 100%
0%
20%
40%
60%
80%
100%
120%
0
10
20
30
40
50
60
70
80
Freq
uency
Manganese Concentration (mg/L)
Source Water Manganese Concentration Histogram2011 to Present
Frequency
Cumulative %
Friday, June 16, 2017 5
Water Treatment Plant Project
• Greensand Filtration Plant• Transmission Mains• Pressure Boosting Station• Boston Street Tank Altitude Valve
Friday, June 16, 2017 6
Treatment Plant Location
Friday, June 16, 2017 7
Treatment Plant Elevation
Friday, June 16, 2017 8
Treatment Methods
• Iron & Manganese Removal– Potassium Permanganate, Sodium Hypochlorite, and Greensand Plus Filters
• Corrosion Control– Aeration, Potassium Hydroxide, and Phosphates
• Disinfection– Sodium Hypochlorite
• Fluoridation– Sodium Fluoride
Friday, June 16, 2017 9
Treatment Plant Ground Floor Plan
Friday, June 16, 2017 10
Treatment Plant Basement Floor Plan
Friday, June 16, 2017 11
Transmission MainsConvey water from sources to the treatment plant.
Mains laid on:• North Street
• Boardman to Ipswich• Ipswich Road
• North to Route 1• Averill Street• Perkins Row
• #250 to Meetinghouse• Meetinghouse Lane• Howlett Street
• Meetinghouse to Route 1
Friday, June 16, 2017 12
Project Costs• Bids opened on May 31st
• Contract #1 – Water Treatment Plant– Low bid of $7.316 million
• Contract #2 – Transmission Mains– Low bid of $1.523 million
• Professional Services– Designer ‐ $784,000– OPM ‐ $256,000
• Project Cost with contingency ‐ $10.4 million– $9.25 million from borrowing– $1.15 million from Retained Earnings / Warrant Articles
Friday, June 16, 2017 13
Rate Impacts
• Water Enterprise Fund– Isolated from tax rate– Project costs recovered through water rates & fees
Friday, June 16, 2017 14
Rate Impacts
• Annual increase of $1.22 per day for average customer– Based on:
• FY2017 water rates• Conservative interest rate• Aggressive repayment schedule
Friday, June 16, 2017 15
Project Benefits
• Water Quality Improvements– Manganese removal
• Pilot testing showed virtually all Mn removed
– More robust corrosion control• Further reduce lead & copper corrosion
– Plant designed to meet Groundwater Rule• Minimum disinfectant contact time requirement
– Water more of a finished product leaving plant
Friday, June 16, 2017 16
QUESTIONS?
Friday, June 16, 2017 17
Booster Station
• WTP site situated on hill, low pressure• Requires fire suppression system• Booster station needed• Will be sized to supply Public Works Building
Friday, June 16, 2017 18
Boston Street Tank Altitude Valve
Friday, June 16, 2017 19
Corrosion Control
• Lead & Copper Rule Compliance
• pH Adjustment– Started in mid‐1990’s– 20+ years in compliance
• EPA changed guidelines– Requires additional treatment method to meet current guidelines – Aeration
Friday, June 16, 2017 20