Transcript Slide 1

In the Face of Drought
Water System Operations
Tom Moss
Deputy Director
Division of Water Supply
June 3, 2008
TAUD Annual Conference
Water Systems in Tennessee
489 Community Public Water Systems serving 94% of State’s Population
148 Surface Water; 192 Ground Water; 149 Purchase Only
Orme, Tennessee
Only Community System that ran completely out of water
It could have been much worse…
•25 systems serving 322,000 people
implemented mandatory conservation
•35 systems serving 500,000 people
asked for voluntary conservation
Public Water Systems (engineers, developers,
systems officials) have:
•Interconnected and merged systems
•Sought more reliable sources
•Extended lines
•Pumped water upstream to protect aquatic
life (temporary pumping schemes)
•Altered reservoir operations
Harpeth Valley UD Interconnections
Parent System
1st
Consecutive
System
2nd
Consecutive
System
Brentwood
NolensvilleCollege Grove,
Milcrofton
Franklin
HB & TS,
Mallory Valley,
Milcrofton
Milcrofton
Harpeth Valley
UD
HB & TS
Mallory Valley
UD
Milcrofton UD
River Road UD
Franklin, HB &
TS, Mallory
Valley,
NolensvilleCollege Grove
Total
Population
Served
169,993
Noah Didn’t Wait Until
It Started Raining to Build the Ark
In the future we will be pushing interconnection
to the extent feasible
And Source Planning/Management
Summer of 2007
Excess Demand – exceeding treatment capacity,
hydraulic capacity
Declining Sources
Failing Sources
Water line breaks, Excessive Leaks
Conservation, Restrictions and Fear of Failure
Issues over reservoir operations
Private wells, Springs and Ponds run dry
Summer 2007
Cont.
•Concern for aquatic life
•Livestock (sometimes resulting in additional
demands on Public Water Suppliers)
•Nursery Industry, Landscaping and Sod
Industry
•Golf Courses, (Greens and Fairways) Athletic
Fields
•Water quality issues – temperature
•Conflicts between uses (livestock, recreation,
drinking water, assimilative capacity, instream flow for biota, temperature
dissipation, etc.)
Water Systems Impacted by Drought
Water Systems Affected by Source Issues
Normandy Lake
November 2007
Duck River Water System Withdrawals
Duck River UC – Tullahoma & Manchester
Shelbyville
Columbia
Bedford County UD
Lewisburg
Spring Hill
Monteagle’s Laurel Lake Fall of 2007
Normal Water Elevation
Upper Intake Point
Monteagle Impoundment : Laurel Lake
Monteagle’s Efforts for Water Supply
Lake Louisa
Monteagle Laurel Lake Intake
Sand Pits
Extraordinary Measures by Alcoa/Maryville
Extraordinary Measures Taken in the Face of Drought
Alcoa/Maryville
Drought Mitigating Rules
1200-5-1-.05(9) – Water Systems are to be interconnected
to the extent feasible
1200-5-1-.05(10) – Water Systems must plan for expansion
when they reach 80% of design capacity
1200-5-1-.17(7) – CWSs must have an EOP (Emergency
Operations Plan) – Many CWSs had Drought
Management Plans. Some were reluctant to
implement them.
1200-5-1-.17(9) - Minimum positive pressure of 20 psi
throughout distribution system
1200-5-1-.17(14) – 24 hours of distribution storage based
on average daily demand
TN Safe Drinking Water Act 2002
Revision
TCA 68-221-711 (8)
The heavy pumping or other heavy
withdrawal of water from a public
water system or its water supply source
in a manner that would interfere with
existing customers’ normal and
reasonable needs or threaten existing
customers’ health and safety.
1200-5-1-.34(5)
(b) The heavy pumping or other heavy withdrawal of water from a public
water system or its water supply source in a manner that would
interfere with existing customers’ normal and reasonable needs or
threaten existing customers’ health and safety.
1. New water withdrawal sources within source water protection
areas, including those that are required to register under the
Water Resources Information Act, T.C.A. 69-8-103, shall be
required to demonstrate through modeling, testing or other
hydrologic means that the public water supply will not be
adversely impacted by the withdrawal. Existing water withdrawal
sources within source water protection areas, including those that
are required to register under the Water Resources Information Act
may be required to perform modeling, testing or other hydrologic
investigations to determine any adverse impact on a specific
public water supply.
Franklin/ Harpeth River
Franklin Water Intake
Golf Course
1) State and federal government agencies
are fragmented in their roles and have difficulty
in dealing with the balancing act of
Pollutant discharge + drinking water + aquatic life
2) The mindset of unlimited supply of water
needs to change
3) “If You Build It, the Water Will Come”
Developers and local government do not
typically take adequate water supply/water
supply infrastructure into account
Community development
hinges on adequate, quality
water supplies
Palo Duro Canyon, Texas
NO WATER = NO GROWTH
$$$ QUESTIONS $$$
• Do we have enough water source
to supply the new facility?
• Does our water system have
the treatment capacity?
• Could the facility endanger
our water supply
if they site the facility here?
The benefits of oversizing for drought or “Big
River” regionalization may have unintended
consequences. Benefits depend on the source
and the receiving source.
•Unused treatment plant capacity could require
higher rates. Water Systems need to sell
water (up to their capacity). It pays the bills.
•Water Quality problems may result from lower
demand, storage tank turnover, etc.
•Transporting water over long distances leads
to water quality issues – disinfection
byproducts
•Higher potential for pharmaceuticals, etc. from
upstream sewage treatment plants on big rivers
•“Carbon footprint” – pumping water long distances
or to much higher elevations increases energy use
• Water Harvesting (off stream reservoirs) and
deteriorating water quality
PPCPs
Pharmaceuticals and Personal Care Products –
Any product used by individuals for personal
health or cosmetic reasons or used by
agribusiness to enhance the growth or health of
livestock
Prescription, over-the-counter (OTC) therapeutic
drugs, fragrances, cosmetics, sun-screen agents,
diagnostic agents, dietary supplements,
biopharmaceuticals, growth enhancing
chemicals used for livestock, and many others
Sources of PPCPs
• Human Activity (e.g., bathing, shaving,
swimming)
• Illicit drugs
• Veterinary drug use
• Agribusiness
• Residues from pharmaceutical
manufacturing
People Contribute PPCPs
• Medication residues pass out of the body
and into sewer or septic lines
• Externally applied drugs and personal care
products wash down the shower drain
• Disposal of unused or expired medications
Drug Classes of Concern
•
•
•
•
•
•
•
•
•
Antibiotics
Antimicrobials
Estrogenic steroids
Antidepressants (profound effects on spawning
shellfish)
Calcium channel blockers (inhibition of sperm activity
in some aquatic organisms)
Antiepileptic drugs
Multi-drug transporters
Musk fragrances (bioaccumulators and persistent)
Genotoxic drugs (primarily used at hospitals)
The major concerns have been with the resistance to
antibiotics and disruption of aquatic endocrine systems
(endocrine disruptors) by natural and synthetic sex steroids
Aquatic organisms have continual exposures, multigenerational exposures, exposure to higher concentrations
of PPCPs in untreated water, possible low dose effects
USGS Study
80% of the streams showed organic
wastewater contaminants –
sampling selection was biased toward
streams susceptible to contamination
(downstream of intense urbanization or
livestock production)
•Steroids, nonprescription drugs and insect
repellents were the chemical groups most
frequently detected
•Detergent metabolites, steroids and plasticizers
generally were measured at the
Highest concentrations
American Water Works Association
“Today’s advanced technology has allowed scientists
To detect more substances – at lower levels – than ever
Before. To date, however, research throughout the
World has not demonstrated an impact on human
Health from pharmaceuticals in drinking water at the
Trace levels at which they have been found. People
Regularly consume or expose themselves to products
Containing these compounds in much higher
Concentrations through medicines, food and beverage
And other sources.
For the many pharmaceuticals that are synthetic organic
Compounds, granular activated carbon (GAC) or powdered
Activated carbon (PAC), reverse osmosis and nanofiltration
Likely to be effective.
Water systems on major rivers (which are more likely to have sewage
effluent discharges upstream) are frequently feeding GAC or PAC
to reduce disinfection byproducts in finished water as well as
To combat taste and odor issues.
Is the Drought Over?
from I.R. Tannehill, Drought: Its Causes and Effects,
Princeton University Press, Princeton, New Jersey,
1947
Legislative Mandates focusing
on drought management
include:
House Bill 2669 (McDonald)
Drinking Water Access and Resources
Planning Act of 2008
Senate Bill 3613 (Kilby)
Tennessee Water Conservation and Drought
Preparedness Act of 2008
House Bill 4209 (Odom)
Water Conservation and Emergency
Preparedness Act of 2008
Water Resources Technical Advisory Committee
The Commissioner of the Department of Environment and
Conservation has established the Water Resources Technical
Advisory Committee as required under T.C.A. 69-7-309, the
Tennessee Water Resources Information Act.
The mission of the 16 member committee is to develop
Recommendations for managing Tennessee’s water resources
To best meet growing demand and drought issues.
On the web at www.tdec.net/boards/wrtac
Contingency Planning
• Emergency Operations Plan for both ground water
and surface water systems {1200-5-1-.34(4)(a)}
• Requirements for:
– Notifications roster
– Response Committee Designees
– Plans for dealing with contamination or loss of
existing sources
1200-5-1-.17(7) CWSs must have an Emergency Operations Plan –
Many have drought management plans. Some were reluctant to
implement them.
1200-5-1-.05(10) Water systems must plan for expansion
When they reach 80% of design capacity
Plan Now or Later
Plan now under your own constraints
With feasibility and time on your side or
Plan later under mandates
If the Water Suppliers Can Show They
Are Already Planning, It May Lessen
Any Impact Later On
TN Safe Drinking Water Act 2002
Revision
TCA 68-221-711 (5)
(5) The discharge by any person of
sewage or any other waste or
contaminant at such a proximity to
the intake, well or spring serving a
public water system in such a
manner or quantity that it will or
will likely endanger the health or
safety of customers of the system or
cause damage to the system.
Dead cow 100 feet upstream of city intake
Cow dumped allegedly as part of farmer
Feud with water plant
1200-5-1-.34(5) Prohibitions in Source Water Protection Areas
(a) The discharge by any person of sewage or any other waste or
contaminant at such a proximity to the intake, well or spring serving a
public water system in such a manner or quantity that it will or will
likely endanger the health or safety of customers of the system or
cause damage to the system shall be prohibited.
1.
Owners or operators of facilities or properties with
potential or actual contaminant sources within close proximity to a public
water supply intake, well or spring or its source water protection area so
as to cause a threat to the water supply may be required by the
Department to develop and implement a pollution prevention plan or
implement best management practices appropriate for the activity…
2.
The Department may require onsite or offsite water quality
monitoring, removal or remediation of the contaminant source by the
property owner or other responsible party for contaminant sources within
source water protection areas which have caused contamination of the
ground water or surface water at levels that have adversely impacted the
public water source to the point that additional monitoring and treatment
are required for the public water system...
3.
Abandoned
wells
within
wellhead
protection areas which are a potential threat to
contamination of the public water supply shall be properly
plugged and closed in compliance with provisions in the
Water Well Act, T.C.A. 69-11-106 (11) by the property owner
or other responsible party. A well that has not been in use
for a period of more than two (2) years shall be considered
abandoned unless the owner of the well can demonstrate a
need for the well and provide adequate protection to
ensure the well will not be a discharge point for
contamination.
Wells used for the regular, ongoing,
collection of water-level, water-quality, or other scientific
measurements are not abandoned, but are considered
observation wells. Observation wells must be properly
maintained and have adequate protection to prevent their
becoming a route for contamination.
TN Safe Drinking Water Act 2002
Revision
TCA 68-221-711 (8)
The heavy pumping or other heavy
withdrawal of water from a public
water system or its water supply source
in a manner that would interfere with
existing customers’ normal and
reasonable needs or threaten existing
customers’ health and safety.
1200-5-1-.34(5)
(b) The heavy pumping or other heavy withdrawal of water from a public
water system or its water supply source in a manner that would
interfere with existing customers’ normal and reasonable needs or
threaten existing customers’ health and safety.
1. New water withdrawal sources within source water protection
areas, including those that are required to register under the
Water Resources Information Act, T.C.A. 69-8-103, shall be
required to demonstrate through modeling, testing or other
hydrologic means that the public water supply will not be
adversely impacted by the withdrawal. Existing water withdrawal
sources within source water protection areas, including those that
are required to register under the Water Resources Information Act
may be required to perform modeling, testing or other hydrologic
investigations to determine any adverse impact on a specific
public water supply.
The local District Attorney can work
with you to enforce on violations
Of the Tennessee Safe Drinking Water Act
for either the “Dead Cow” or
“Soda Straw” Amendment
Potential Contaminant Source Inventory
Requirements
What is in your neighborhood?
Water Systems must assist in
Maintaining a picture of their
surroundings
TCA 4-29-120. Notification of interested persons
— Notification registry — Rules and regulations.
(a) Prior to issuing a permit or hearing an appeal
from a person who has been denied a permit for
a proposed project or action, each department
and agency of the state shall provide personal
notification to all interested persons who have given
the department or agency the information required
pursuant to subsection (b). The notification shall be
given at least fifteen (15) days prior to the issuance
of a permit or hearing an appeal for the purpose of
giving all interested persons an opportunity to review
and comment on the proposed project or action.
(b) To effectuate subsection (a), each department and
agency of the state shall create and maintain a notification
registry for the purpose of allowing individuals who would
be affected by the issuance of a permit to contact the
department and agency and have the individual's
full name and electronic mail address entered in the
registry for notification purposes.
Ask to be Put on Notification Registry for Permits
Issued in Your Watershed/County/Adjacent Counties
Notifications are E-mail only
In regard to National Pollutant Discharge Elimination System (NPDES )
Permits from the Division of Water Pollution Control,
Concerns can be both upstream and downstream
Discharge permits have assimilative capacity figured into them
(how much stream flow is necessary to dilute the waste discharge)
And raise the instream flow requirements, effectively reducing the
Amount of water you can withdraw.
ARAP (Aquatic Resource Alteration Permits) are also a concern and
Address any altering of the stream, including withdrawals
Contact: [email protected]
Ask to be put on the notifications list
For NPDES permits and ARAP permits
In your area (watershed/county or counties)
As well as stream reclassifications
For Solid and Hazardous Waste facilities,
Contact the Division of Solid Waste Management:
http://state.tn.us/environment/swm/maillist.shtml
When in Doubt, e-mail [email protected]
And request notifications from Water Pollution Control
And Solid Waste Management
If your drought plans or long term plans
include anything requiring an ARAP permit,
Corps of Engineers Permit, etc. you should already
Have one in place or ahead of the time you need it
An ARAP permit may keep you from
getting your withdrawal
Or reservoir from being built (“Antidegradation”)
ARAPs are even a consideration for
Withdrawals from springs
Stream classification or reclassification to a
higher grade /more protected Tier stream will
Keep you from getting your withdrawal as well
See to it that ARAP withdrawal or stream modification permits
are acted upon (approved or denied) and the process is not
sidestepped – reclassifying streams, asking for additional
studies, “table-ing” the permit cannot be appealed as
Could a permit denial
New ground water sources will have to have
one mile radius review of significant potential
contaminant sources
New surface water sources will have to have
five mile upstream review of significant potential
contaminant sources and review of permitted
discharges fifteen miles upstream
Water System Operations
Water Quantity and Quality Issues
Water Quality Issues
Chlorine residuals must be maintained –
Otherwise looking at boiled water advisory
Drought problems will not stave off formal
enforcement action on MCL violations for DBPs
Treatment Plant Optimization to control organics,
Turbidity, taste and odor should reduce
The need for flushing
Treatment Plant Optimization will likely also increase
Filter run times, reduce needed backwashed
And conserve water being wasted from the plant
Water Quantity
Flushing should be timed and planned around
the time periods when source water is abundant
and demands low –
You don’t need to be flushing when you
Are maxed out on hydraulic capacity
Unaccounted for water/leaks?
Meter Replacement Program?
Water Quality Issues with Drought
DBPs and Taste & Odor
Optimization of coagulation for organic removal
Point of Chlorine addition
Activated carbon
Oxidizers
Hydrogen Peroxide and Potassium Permanganate
Beware that hydrogen peroxide will mobilize any
Manganese present within the water plant
Remove as Much of the TOCs as You Can
Before Chlorination
May need to add PAC or GAC
Lower pH during flocculation and sedimentation
Switch coagulants (some have a pH buffer)
Optimal pH range for TOC removal is 5.5 – 6.0
but would have to adjust post sedimentation
to keep down corrosiveness on lead and
copper
Optimizing the Plant May Require Change in
Operations/Management
• Plant operations may need to be spread out over
more than 1 or 2 shifts rather than running the plant
at maximum with minimum water residence times
– It is not the large systems that are having trouble meeting
DBP standards, it is the small and medium systems running
1 – 2 shifts.
Tools for Reducing DBPs Requirements
• Using chemical or physical processes to
remove precursors from source waters
• Moving the point of disinfection after
clarification
• Using enhanced coagulation before
disinfection
• Changing primary or secondary disinfectant
• Optimize the pH for coagulation process
Florida Rural Water Association; Reducing Disinfection Byproducts
TOC Removal Using Enhanced
Coagulation
TOC
Mg C /L
Alkalinity (CaCo3)
0-60
60-120
>120
2.0 to 4.0
4.0 to 8.0
>8.0
35%
45%
50%
15%
25%
30%
25%
35%
40%
TOC Target level should be 1.0 mg/l, EPA’s push for 2.0
could still leave you with DBP violations
Florida Rural Water Association; Reducing Disinfection Byproducts
With Carbon or Hydrogen Peroxide
• The pH and alkalinity may have to be adjusted
for the process to work
• May have to re-adjust pH before leaving the
plant
Enhanced Coagulation – Optimizing for
Turbidity versus TOC Removal
• Enhanced coagulation for turbidity is not the
same as for TOC/DBP minimization
– Just because you meet the 2.0 ppm TOC
does not mean it is optimized for DBPs
and you won’t still have a DBP problem
The target should be 1.0 ppm TOC
• Optimizing TOC removal will actually give
you a slight rise in turbidity
Reducing the Production of Disinfection
By-Products
•
•
•
•
Precursors (TOC) Removal
Disinfection By-Product Management
Use of Alternative Disinfection Strategies
Disinfection By-Product Removal after
Production
Precursor (TOC) Removal
• Nutrient and biota control in source and finished
water
• Use of solids removal treatment systems including:
– Presedimentation, coagulation, sedimentation or
membrane filtration
• Use of activated carbon or potassium permanganate
• TOC Target level should be 1.0 mg/l, EPA’s push for
2.0 could still leave you with DBP violations
(particularly TTHMs)
TOC Removal Using Potassium
Permanganate
• Long Used for Taste and Odor
• Removes color forming substances which are the
same constituents that cause DBP formation
• Range of dosage vary on water quality with 0.25 mg/l
to 20 mg/l.
• Average dosage is 2 to 4 mg/l with 30% TOC removal
efficiencies reported
Florida Rural Water Association; Reducing Disinfection Byproducts
TOC Removal using Activated Carbon
• With Source Water TOC from 2 to 4 mg C/L
Activated Carbon Systems typically remove
>50%
• Activated Carbon comes in two forms:
– Powdered Activated Carbon (PAC)
– Granular Activated Carbon (GAC)
Removal mechanisms are the same
Florida Rural Water Association; Reducing Disinfection Byproducts
Carbon Use
• You will need to try different types of carbon
(wood versus coal based carbon – Hydrodarco
has been found to work well and is a coal
based powdered activated carbon)
You need to give the carbon time to work and
add enough to do the job (at least 5 ppm
carbon to start)
Effects of pH on the Production of DBPs
TTHM and HAA5 Potential Formation
Amy et al 1987
Franchi et al 2002
Florida Rural Water Association; Reducing Disinfection Byproducts
Disinfection Byproduct
Management
• Reducing detention time in storage tanks
• Ensuring turnover in distribution system
• Flushing dead end lines
Water Age and DBP Production
Franchi and Hill, 2002
Florida Rural Water Association; Reducing Disinfection Byproducts
Typical Distribution System Water Age
(Days)
Population
Miles of WM
Water Age
>750,000
>1,000
1 – 7 days
<100,000
<400
>16 days
<25,000
<100
12 – 24 days
AWWA: Water Age for Average and Dead End Conditions
Problems with Water Turnover
and Sediments in Tanks
Sediments contain significant concentrations
of organic nutrients
Sediments exert a disinfectant demand
Sediments provide a protective layer for biofilms
which allow pathogens to repair
Sediments encourage the growth of slow growing
nitrifying bacteria that lower residual
Can contribute toward the formation of DBPs
Can cause turbidity, taste and odor problems
Florida Rural Water Association; Reducing Disinfection Byproducts
Use of Disinfectant Strategies
• Reduce Dosing Concentration of Disinfectant
• Change Points of Application
• Change Forms of Disinfectant
• Use of Multiple Disinfectants
• Change Disinfectant
Florida Rural Water Association; Reducing Disinfection Byproducts
The Division of Water Supply discourages changing
disinfectants from chlorine, any change will require
approval and lose reduced lead and copper monitoring
Chloramines - will affect the corrosion of lead and
copper in your distribution system.
Does not provide the same disinfectant strength as
chlorine.
Will give you taste and odor problems and nitrification.
You will still have to have free chlorine residual in
distribution system according to DWS rules
Chlorine dioxide – strong cat urine odor; will require
additional monitoring.
Will still have to have free chlorine residual in
distribution system according to DWS rules
Effect of the Addition of Free Chlorine
At MCL+ Level with TOC
Florida Rural Water Association; Reducing Disinfection Byproducts
Chlorine Dose and Its Effect on DBP Production
Florida Rural Water Association; Reducing Disinfection Byproducts
Effects of Moving the Point of Disinfection
Florida Rural Water Association; Reducing Disinfection Byproducts
Percent Reduction in DBP Formation by Moving
Chlorination Point Later in Treatment Train
Chlorination
Point
TTHM
Baseline (%)
TTHM
Enhanced (%)
HAA5
Baseline (%)
HAA5
Enhanced (%)
Pre-rapid mix
Basis
17
Basis
4.7%
Post rapid mix
1.6
21
5.3
21
Mid flocculation
8.7
36
14
36
Post
sedimentation
21
48
35
61
EPA Alternative Disinfectants and Oxidants Guidance Manual
Treatment Plant Optimization
to control organics, turbidity, taste and odor
should reduce the need for flushing and keep
DBPs at lowest levels
Protect Your Source
Interconnection
Plan Ahead