NC AWWA‐WEA 2015 Annual Conference
November 16, 2015
Source Water Protection and Detection of
Chemical Contaminants
Ben Wright
Ben Stanford
Alison Reinert
VA AWWA 2012
Overview
 Source water protection drivers
 Data resources
 Assessing risk
 Emergency response and risk mitigation
 Early warning and detection
Drinking Water Treatment
 Treatment plants are typically designed to
remove turbidity, pathogens, natural organic
matter, and some limited inorganics
Chemical Contamination
 Petroleum hydrocarbons
 Industrial chemicals
 Pesticides
Chemical and Petroleum Treatment
 Treatability depends on chemical characteristics
 Dedicated treatment for chemical or petroleum
contamination requires multiple processes to
remove specific contaminants
Chronic Contamination
 Low concentrations of chemical contaminants
may be attenuated naturally through dilution,
adsorption, volatilization, degradation, etc.
 Too many low concentration inputs can
overwhelm natural processes
Acute Contamination
 Releases of large quantities of chemicals can
make surface water supplies unusable for a
period of time
 Recent events have highlighted vulnerabilities
for many water supplies:
 Elk River, WV (chemical spill)
 Danville, VA (coal ash spill)
 Lynchburg, VA (crude oil
train derailment)
 St Charles Parrish, MS
(barge oil spill)
 Kalamazoo, MI
(oil pipeline failure)
Source Water Assessments
 1996 amendments to the SDWA, placed new
emphasis on source water protection
 Required states to develop programs to assess
the susceptibility of source waters to
contamination
 Risk profiles change over time
 New/different sources of industrial pollution
 Changing land uses
 Response measures may not currently be adequate
(i.e. increased demands)
 Regulatory landscape may be different (MCLs)
 New regulations in NC will require more from
individual utilities
NC Source Water Assessment Program
 Two component contamination susceptibility rating
 Inherent vulnerability rating
Surface Water Source Characteristics
Watershed Classification
Intake Location
Treatment plant raw water quality data
Watershed Characteristic Evaluation
Higher
Vulnerability
Moderate
Lower
X
X
X
X
 Contaminant rating – based on density and relative
risk of potential contamination sources
 Overall susceptibility rating based on combination
of the two ratings
Source Water Protection Planning Steps
 Characterize the watershed and identify risks
 Set goals and identify solutions (response and
mitigation)
 Design an implementation program
 Build partnerships
 Implement the plan
 Measure progress
 Re-evaluate plan and
make adjustments
Watershed Characterization Data Sources
 Access to GIS data and many government
databases have increased ability to efficiently map
potential sources of contamination
 State and Federal government databases of
georeferenced data to ID potential sources of
contamination (PSC)
 USEPA Envirofacts
 Toxic Release Inventory, NPDES and other permits
 USDOT Pipeline mapping
 NJDEP Pollutant Discharge Elimination System
database
 NJDEP Data Miner app
 NJDEP Land Use/Land Cover GIS data
Data Sources with Limited Availability
 Transportation networks (rail and highway)
 Specific chemicals stored at industrial facilities
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Available per EPCRA
Limited online availability
Self-reported data
May be redacted due to
trade secrets
Assessing Risk
 Many watersheds have hundreds of potential
contaminant sources, many with unknown
type/volume of material
 What is the chance that chemicals will get to your
intake or well in high enough concentrations to
cause an impact?
 Overall risk is based on both high risk sources and
effectiveness of response measures
 Not all sources are high risk, important to identify
the ones that are
Assessing Risk - sources
 Factors affecting risk
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How close/how concentrated are PSCs
Surface vs underground storage
Age of facilities
History of releases
River/reservoir/
groundwater
dynamics
 Natural attenuation
Assessing Risk - responses
 How confident of notification in a timely manner
 What are the existing communication protocols
between industry, regulators, utilities, etc.
 Are they tested regularly (e.g. mock spill)
 What is your ability to maintain deliveries during
an incident
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Storage capacity (raw and finished)
Demand levels (seasonal, peak)
Effective treatment processes
Availability of lab resources
Emergency Response Measures
 Shutdown intakes / turn off wells
 Typically least expensive
 Effective, but reduces supply reliability
 Requires sufficient storage for duration of shutdown
 Emergency conservation can result in short term spikes
in usage
 Emergency treatment
 High cost
 Effectiveness dependent on chemical properties (no
silver bullet)
 Alternate water supply from different source
 High cost to maintain redundancy
 May provide resilience to other emergencies (drought)
Risk Mitigation
 Develop relationships with key industrial PSCs
 Encourage direct line of communication for spills
 Work with other utilities to share resources
 Implement an early warning system
 Develop contacts to build a knowledgebase
 University professors and researchers
 Poison Control Centers
 Specialized consultants
 Communicate with regulators beforehand to
identify response measures, treatment targets,
recovery plan, etc. and get support for plans
 Work with basin stakeholders for education and
public outreach
Early Warning and Detection Technologies
 Commercial Technologies
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Wide price range $50-$70,000
In-situ and ex-situ sampling
Grab and online monitoring
Fluorescence
Purge and trap (GC-MS)
Fiber optics
Detection strips
Light pulsation
Absorption
Film detection
Liquid detection
Comparison of Detection Technologies
Accuracy and Range
 There are numerous sensor technologies on the
market that provide different capabilities at a
range of costs
Capital and O&M costs
Comparison of Detection Technologies
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Accuracy and Range
Optical Sensors
Cost $8k to $15k
Ex. Petrosense DHP 485
PPM level detection of
TPH and BTEX
• submersible unit that has
no consumables
• minimal maintenance
Capital and O&M costs
Comparison of Detection Technologies
Accuracy and Range
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•
•
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Fluorescence Sensors
Cost $20k to $30k
Ex. TD 4100 XDC
PPB level detection of chemicals
or petroleum
• Cannot detect for multiple
chemicals at same time
• Can be recalibrated quickly
• Moderate regular
maintenance
Capital and O&M costs
Comparison of Detection Technologies
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•
•
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Accuracy and Range
Gas chromatograph Sensors
Cost >$50k
Ex. Inficon CMS 5000
PPT level detection of
chemicals and petroleum
• Higher cost and level of
maintenance
• Recommended for when it is
necessary to regularly
monitor for a range of
constituents
Capital and O&M costs
Selected Additional Resources
 AWWA
 G300-07 Standards for Source Water Protection
 J-100-10 Risk Analysis and Management for
Critical Asset Protection (RAMCAP®)
 Water Research Foundation
 Project 4176: Developing a Vision and Roadmap
for Source Water Protection for U.S. Drinking
Water Utilities
 USEPA
 A Water Security Handbook: Planning for and
Responding to Drinking Water Contamination
Threats and Incidents
Questions?
Ben Wright, P.E.
bwright@hazenandsawyer.com
(410) 539-7681
VA AWWA 2012