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A Public Water System’s Perspective Lessons to be Learned April 6 th , 2016 Jesse Stewart: SLCDPU Water Quality Administrator Arlene Larsen: Regulatory Program Manager
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A Public Water System’s Perspective
Lessons to be LearnedApril 6th, 2016
Jesse Stewart: SLCDPU Water Quality AdministratorArlene Larsen: Regulatory Program Manager
What We Take For Granted
What Does the Public Expect?
Public Water Supply H2O Quality in Utah and the US Generally good Regulated by state and federal laws - Safe
Drinking Water Act (SDWA).-1974 Requirements:
Regulates drinking water quality of the public water supplies.
Public notification for violation of standards. Regulates operational requirements for treatment plants
and distribution systems. Publish Consumer Confidence Reports
Due diligence above and beyond Public health implications
Agenda, Questions, Lessons?
Overview of Flint MI Lead sources Lead in drinking water - chemistry Monitoring and response Communication Public perception and trust
Flint Summary April 2014 switched to Flint
River water. Color, taste, odor, rashes,
bacteria August/September 2014
Boil order for bacteria October 2014
General Motors stops using Flint water
January 2015 Detroit water offers to
reconnect waiving connection fee
Flint officials decline offer February 2015
Lead testing – 104 ppb (could be understated, EPA expert)
March and May 2015 Lead testing – 397ppb Consultant report – Flint
water meets standards
August 2015 Flint to optimize corrosion
control September 2015
Virginia Tech professor – corrosive Flint water is causing lead to leach from pipes
High levels of lead in children’s blood
October 2015 Flint city officials urge residents
to stop drinking municipal water Flint reconnects to Detroit water
December 2015 Flint adds additional corrosion
control Flint declares a State of
Emergency January 2016
President Obama declares a State of Emergency
Flint Summary (cont)SO WHERE DID THINGS GO WRONG? Change of water source “cost-saving”
Due diligence Corrosion control - orthophosphate? Protective coating on the lead pipes removed Old infrastructure
Customer calls: Residents observed a change in water quality
issues (e.g., red water, taste, odor, corrosion at GM)
Communication
Flint Summary (cont) Sampling and analysis
for a range of possible contaminants was performed by various entities (e.g., residents, universities, State).
Lead concentrations: Greater than 100-300 (ppb)
Protection Agency (EPA) action level (AL) is 15 ppb. The action level triggers further monitoring or actions. The AL is based on the
90th percentile level at tap water samples. An AL exceedance is not a violation but can trigger other requirements that included water quality parameters (WQP) monitoring, corrosion control treatment (CCT), source water monitoring/treatment, public education, and lead service line replacement (LSLR).
Reported inaction by agencies
Lead Sources 3000 BC: first significant mining and refining of lead 500 to 100 BC: lead poisoning described, widespread use of lead in
utensils and cook ware 1400-1500: lead used as a poison 1620’s: lead first mined in North America 1850’s: Tetraethyl Lead (TEL) discovered 1880’s: US medical authorities diagnose child lead poisoning 1909: France, Belgium, Austria ban white-lead interior paint 1916-1922: Anti-knock research engines, Tetryethyl Lead research
1922 1922: League of Nations bans interior lead paint 1970: GM President promises “pollution-free” cars by 1980, urges
elimination of lead additives. 1980: EPA regulations to allow-phase out or leaded gasoline 1982: Reagan Administration reverses phase-out 1984: Chicago bans leaded gasoline (New York had ban in place
since 1928) 1986: “Lead-free” plumbing amendment to SDWA 1994: 78% decline in lead blood levels between 1978 and 1991
Lead Sources It is a Neurotoxin –affects every system in the body.
Children (6 years and younger) most at risk Lead paint (cited as most common exposure)
First Regulation of Lead paint enacted in 1920’s. Leaded gasoline
1984 City of Chicago bans leaded gasoline, New York 1928 Lead in household plumbing materials
Lead Solder used by plumbers to connect copper plumbing Lead pipes in older homes Prohibition of lead in plumbing materials
1986: Solder and flux < 0.2% lead and Pipes < 8% 1996: plumbing fittings and fixtures (endpoint devices) 2011: lowering the maximum lead content of the wetted surfaces
from 8% to 0.25% Some exceptions – non-potable uses
Lead Health EffectsNeurotoxin –affects every system in the body
Children (6 years and younger) most at risk
Can Lead Get in the Water?
How?
Lead Flow Diagram
Corrosion Due to pH, alkalinity and hardness. For water corrosion will be minimal at
pH near neutral Alkalinity > 30 mg/L Hardness > 50 mgL
Addition of orthophosphate reduces corrosion. Simplest source – Phosphoric acid Reaction with lead pipe to form a Lead Phosphate
complex to form a barrier.
How Do We Compare?
Water Hardness
Hard Water – Not Visible
Hard vs Soft Water
Use of Polyphosphates Added to some wells as a sequestering
agent. Combines a chelating agent and metal ions
(calcium and iron) to form a soluble complex. Interferes with crystal growth. Retards scale formation. Type of polyphosphate used depends on pH
Neutral pH: Sodiumhexametaphosphate (SMPH) Alkaline: pyrophosphate and polyphosphate
Alkalinity Defined as its capacity to neutralize acid Due to the presence of one or more of a
number of ions. Hydroxides Carbonates Bicarbonates
Moderate concentrations are desirable to balance corrosive effect.
Langelier Index The Langelier Index is an approximate indicator of the
degree of saturation of calcium carbonate in water. Calculated using pH, alkalinity, calcium concentration,
total dissolved solids, and water temperature of a water sample collected at the tap.
Langelier Index is negative – Under-saturated with calcium carbonate Tend to be corrosive in the distribution system
Langelier Index is positive – Over saturated with calcium carbonate Tend to deposit calcium carbonate forming scales in the distribution
system If Langelier Index is close to zero –
then the water is just saturated with calcium carbonate and will neither be strongly corrosive or scale forming.
SLC Chemistry Ranges pH: 7.5 - 8.3 Alkalinity: 124 - 303 mg/L Calcium: 33.1 - 126 mg/L TDS: 192 - 756 mg/L Temperature: varies seasonally Calcium Hardness:
132– 478 mg/L 7.7 – 27.9 grains /gallon
Where Did Things Go Wrong?
Monitoring, Response, and Communication
SLCDPU protocols Water sources Changes to water sources Infrastructure, line breaks Testing, 170 compounds, > 16,000 tests
Langlier Index monitoring Response to customer complaints
SLCDPU Overview State and Federal
Regulation SLC’s 3-phase approach
Source Protection Surface water and groundwater
Treatment Distribution
All-Phases – Routine monitoring for
potential contaminants, including Pb and Cu
Public health implications
Water Sources Majority from snow melt flowing in our mountain streams. Deep wells are added during summer months to supplement
demand.
Rigorous Monitoring Salt Lake City – meets or exceeds all EPA
requirements. Watershed Treatment plants, wells and reservoirs Distribution system
Lead and Copper Results
Salt Lake City Department of Public Utilities 2015 Lead and Copper Sampling First Draw After Flushing First Draw After Flushing
Lead
AL of 15 ppbLead
AL of 15 ppbCopper
AL of 1300 ppb Copper
AL of 1300 ppb
count 57 57 57 57
Concentration (ppb) at 90th Percentile
6.80 1.26 243.40 59.24
Ave (<1.00 calculated as 1.00)
(ppb) 3.01 1.16 114.19 28.46
Min (ppb) <1.00 <1.00 4.72 2.71
Max (ppb) 21.90 6.02 706.00 110.00
Lead and Copper Rule Monitoring Every three years90th percentile below 15 ppb EPA Action LevelIn-line with other Utah PWSs
What You Can Do
Water testing Local laboratories
Run the cold water “lead-free” plumbing Maintain home treatment systems
Public Perception and Trust
Public Perception and Trust
Education and interactions
Public notice Customer inquiries Customer complaints Consumer
Confidence Reports Community Council
meetings
Questions???
We Take it for Granted
Web Sites http://www.deq.utah.gov/Pollutants/L/lead/LeadinWater.ht
m
http://dequtah.blogspot.com/2016/02/why-flints-water-crisis-couldnt-happen.html?m=1
http://www.nsf.org/consumer-resources/health-and-safety-tips/water-quality-treatment-tips/lead-in-drinking-w
http://dequtah.blogspot.com/search/label/Drinking%20Waterater/
