Groundwater Under Direct Influence of Surface Water, What To Do?

Groundwater Under
Direct Influence of
Surface Water,
What To Do?
AWWA NY
Water Event and Expo, Rochester, NY
May 13-15, 2014
Gerard T. Remsen, III, P.E., United Water
Michael Johnson, P.E., BS&J
1
Outline
 UWNY Background
 LT2 Rule
– EPA
– Factors that trigger compliance
 Treatment Techniques
– UV, Filter, Chemical, etc.
 Case Studies
– Three (3) wells
– Start up/Operation Procedures
2
UWNY Background
 UWNY Owns and Operates System and
Serves Most of Rockland County, NY
 Serves More Than 270,000 Customers
 Peak Daily Demand: 44.8MG
 Over 1,000 miles of water lines, 68,000
meters, 6,100 hydrants, and 62
operating wells
 Grotke Well 83, Pomona Well 37, and
Ramapo 29A – Groundwater Under
Direct Influence of Surface Water
(GWUDISW)
 Schedule Eighteen (18) months
3
LT2 Rule
 Long Term 2 Enhanced Surface Water
Treatment Rule (LT2ESWTR)
– Improve drinking water quality
– Protection from disease causing microorganisms and
contaminants
– Applies to all PWS that use SW or GWUDISW
 GWUDISW Factors (varies by state)
– Type of well (spring, horizontal collection well,
unconfined aquifer or recharge well)
– Adjacent to surface water
– Well Construction (shallow/deep, annular space)
– Water Quality (periodically +TC or +E. Coli)
 Hydrogeological Investigation
– Hydraulic connection (seismic reflection survey, seepage
investigation, or thermal infrared imagery)
 Microscopic Particulate Analysis (MPA)
– Low, Medium, or High Risk
– Algae, Diatoms, Pollen, Protozoa, Giardia, Crypto, etc.
4
LT2 Rule
 2-log Crypto (or 5.5 if raw water not monitored)
 3-log Giardia , and
 4-log Virus
 Treatment Options
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Watershed Control
Alternative Source/Intake
Bank Filtration
Pre-sedimentation
Lime Softening
Filter
Chlorine Dioxide
Ozone
UV
Membrane Filtration
 Most commonly achieved by small systems:
– Removal with Filters (SWTR)
– Inactivation with UV (LT2)
– Treated with Hypo
5
Filters
 Refer to Ten State Standards
 Bag and Cartridge Filters
– Low Loading capacity for small
systems
– Discard filter after expended
– Effectively removes Crypto (2-5 μm)
and Giardia (5-10μm)
 Challenge Testing
– Product specific, not site specific
– Full scale
– Challenge particulate
– Test solution concentration
– Up to 2 log for bag or cartridge filter
showing 3 log removal
– Up to 2.5 log removal in series
showing 3 log removal
6
Filters
 Advantage
– Low maintenance, low capital,
minimal training
 Disadvantage
– NSF, Headloss, Replace filters,
redundancy, biofilm clogging, limit
surges, larger flows consider
membrane or other
 Turbidity < 3NTU or less
depending on
manufacturer, may need
pre-treatment
 UV treatment may require
pre-treatment if >1 NTU
 MPA proof after installed?
7
UV
 Damages microorganisms and prevents replication
 No residual
 Validation testing, see UV Disinfection Guidance Manual
– In English
Partial Exhibit 13.1 UV Dose Requirements – mJ/cm2
Target Pathogens
Log Inactivation
1.0
2.0
3.0
4.0
Crypto
2.5
5.8
12
22
Giardia
2.1
5.2
11
22
Virus
58
100
143
186
8
Types of UV Devices
 Many types of reactors, two (2) types typically used:
1. Medium Pressure (MP) and
2. Low Pressure High Output (LPHO)
More information see Ultraviolet Disinfection Guidance Manual
at:
http://www.epa.gov/OGWDW/disinfection/lt2/pdfs/guide_lt2_uvguidance.pdf
9
Characteristics (LPHO vs.
MP)
 Reactors can be s-shaped, ushaped, or in-line
– Typically LPHO require larger
footprint
 Lamp life
–
LPHO 8,000 to 12,000 hours
– MP 4,000 to 8,000 hours
 Power
– LPHO require less power, more
lamps
 Sleeve Cleaning
– LPHO use Off-line chemical clean
(OCC) systems, more labor
– MP use On-line Mechanical (OMC)
systems, more parts to replace
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Factors To Consider
 Validation of UV device
– For installed conditions and no increasers US or DS within 10 times diameter of reactor
 PWS monitor for flow rate, lamp status and UV intensity
– UV absorbance if in dose monitoring strategy
 Fouling: Ca+2, Alkalinity, Mn+2, pH, Fe+2 and Hardness
 Head loss
 Off-spec reporting
 Advantages: Lowest cost treatment for Crypto and Giardia, no
DBP, not impacted by pH or temperature
 Disadvantages: no residual, high UV dose for Virus inactivation,
power quality
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General Process Arrangement
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 Pump starts flow to waste
 until NTU level is 1 or less
 Emergency Shut Off Valve Closed
 Recirculation pump starts
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NTU less than 1
Flow to filter and discharge to
waste until NTU level is below 0.3
1st waste line closed
Recirculation pump still operating
Emergency valve still closed
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15
UV unit reaches Intensity and temperature
Recirculation pump shuts off
Emergency valve opens
Flow to distribution system
Chemical feed pumps on
Chlorine Analyzer running
Full Scale Implementation
 Grotke Well 83
– 200gpm well @ 360TDH
– 12’ x 22’ Wellhouse
– Seaquest and Hypo
– Wetlands nearby
– March 30, 2011 GWUDISW,
18 month schedule
16
Prior to Construction
Full Scale Implementation
Grotke Well 83 As Constructed
Construct within existing building
New 200gpm @ 454 TDH VTP
17
Waste/blow off piping
Harmsco MUNI-3-3FL
Full Scale Implementation
Grotke Well 83 As Constructed
Harmsco MUNI-3-3FL
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InLine 200+ DVGW UV
6”x6” Tee
Magnetic Flow meter
Surge Anticipating Valve
M.O. Spring Return BFV
35LF of 36”Ø DIP
Full Scale Implementation
 Pomona Well 37
– 250gpm well @ 450TDH
– 12’ x 20’ Wellhouse
– Seaquest and Hypo
– Wetlands nearby and high
pressure
– March 30, 2011 GWUDISW,
18 month schedule
19
Prior to Construction
Full Scale Implementation
Pomona Well 37 As Constructed
Construct within existing building
New 250gpm @ 582 TDH Submersible
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Waste/blow off piping
Harmsco MUNI-3-3FL
Recirculating Pump
Full Scale Implementation
Pomona Well 37 As Constructed
InLine 200+ DVGW UV
6”x6” Tee
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Magnetic Flow meter
Surge Anticipating Valve
M.O. Spring Return BFV
115LF of 36”Ø DIP
Full Scale Implementation
 Ramapo Well 29A
– 1200gpm well @ 609TDH
– 16’ x 13’ Wellhouse
– Seaquest and Hypo
– Floodplain and High Pressure
– May 2012 GWUDISW, 18
month schedule
22
Prior to Construction
Full Scale Implementation
Prior to Construction
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Filter
235psi
Hypo
UV
reactor
Well
Surge
Valve &
Fail Safe
BFV
<150psi
Booster
Pump
Waste
195LF-36”Ø
1. Raise
Well
2. Add
Filter in
Elevated
Platform
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3. Raise
piping
and add
UV
4. Boost and
Provide CT in
larger Ø pipe
Full Scale Implementation
Ramapo Well 29A As Constructed
Raise All Treatment Components
New 1400gpm @ 372 VTP (Lower head)
New Elevated Treatment
Enclosure
25
Full Scale Implementation
Ramapo Well 29A As Constructed
UV Reactor
Parallel Treatment Trains
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Full Scale Implementation
Ramapo Well 29A As Constructed
Waste/blow off piping
Harmsco MUNI-3-3FL
Booster Pump
Surge Valve Vault
Y-Strainer
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Summary
 NSF Listing
 UV Validation
 UV and Filter Treatment: multiple barriers
 Several types of control for UV systems
 Think Vertical
 Start-up and testing
 Learning Process
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We were assisted by and would like to thank:
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Entire staff at United Water
Bill Prehoda, P.G., UWNY
Nick Curcio, UWNY
Sam Rulli, P.E., Rockland County DOH
Dan Miller, Ph.D, Rockland County DOH
Brock Rogers, P.E., NYS DOH
Ronald von Autenried, P.E., BS&J
J. Fletcher Creamer & Son, Inc. (Contractor)
Aquionics Inc. (UV)
Harmsco Filtration Products (Filter)
Quality Controls, Inc. (Fail Safe BFV)
Baker Manufacturing Company, LLC (Booster Pump)
29
Thank You!
Gerry Remsen:
[email protected]
Michael Johnson
[email protected]
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