At first it was thought that Flint’s water treatment plant used corrosion control chemicals, but officials later stated that it did not, presumably to reduce costs. Without corrosion inhibitors, tap water tends to contain much higher levels of lead and minerals.
Full Answer
Why was there no corrosion control in the Flint water treatment plant?
Back in 2014, Flint water treatment workers expected they'd add corrosion control to the city's drinking water -- chemicals that would that would have prevented a public health crisis -- …
What does a Flint water treatment plant employee do?
· Because the water treatment plant was in poor condition due to lack of maintenance, the engineer recommended that, using Flint River water, the city run the plant on a trial basis for “60-90 days...
Can chemistry solve the Flint water crisis?
· Why didn't Flint treat its water? An answer, at last Back in 2014, Flint water treatment workers expected they'd add corrosion control to the city's drinking water -- chemicals that would that...
Why is the city of flint renovating its water system?
As shown in Figure 7, before July 2015, when the alkalinity of the water was greater than 50 mg/L as CaC0 3, the CSMR values of the treated Flint River water exceeded the 0.5 cutoff, so the corrosivity of water would have been a significant concern. After this time, the alkalinity of the water was less than 5 0 mg/L and the CSMR greatly exceeded 0.2, indicating that lead …
Why didn't Flint treat its water an answer at last?
The report called Flint River water "highly corrosive" and cited the lack of corrosion control used to treat it. In February, Virginia Tech researcher Marc Edwards published a peer-reviewed paper that found the decision not to use corrosion inhibitors to treat Flint River water was most likely the cause of the crisis.
What was missing from the Flint water treatment process?
“That missing lead represents what was leached from the pipes during the Flint corrosion episode.” As lead pipes age, the atoms on their surface react with oxygen and other chemicals in the system and become oxidized, or rusted. Adequate water treatment doesn't prevent that process.
How did trihalomethanes get in Flint water?
When coliform bacteria were detected in distribution system water samples, water utility managers were obliged by law to increase the levels of chlorine. The higher levels of chlorine, while reducing coliform counts, led to the formation of more trihalomethanes.
Why was Flint's water corrosive?
The chemistry of Flint River water was known to be highly corrosive to lead plumbing as well as iron pipe due to its high chloride content, which was about eight times higher than the chloride content in the DWSD water.
What was not added to water sourced from the Flint River?
By press time, C&EN was unable to get a comment from Flint city officials about why a corrosion inhibitor wasn't added to the river water. The entire Flint water crisis could have been avoided if the city had just added orthophosphate, Edwards says.
Does Flint have clean water 2021?
Flint broke the internet when its crisis went viral. As you would expect, things have changed for the better — meaning the water is technically clean — but the scars of the scandal may last far longer. The city of Flint has replaced over 10,000 pipes to deal with lead in the water.
How do you remove trihalomethane from drinking water?
The easiest way to reduce or eliminate THMs in drinking water is to use a water pitcher with a carbon filter, install a tap-mounted carbon filter, or to use bottled water. When using a filter, check to verify that it is certified to remove THMs and follow replacement instructions recommended by the manufacturer.
Does a Brita filter remove trihalomethanes?
Brita's faucet filtration filters about 30 substances including asbestos, cloudy soil runoff (aka turbidity), benzene and trihalomethanes (THMs, the carcinogenic by-products of water disinfection), 2,4-D, carbofuran, styrene, toluene, VOCs and, yes, lead.
Why is trihalomethanes a concern?
Exposure and Risk When people consume trihalomethanes at high levels over many years, they increase their risk of developing bladder cancer. Other health effects that may be associated with trihalomethanes include rectal and colon cancer, and adverse developmental and reproductive effects during pregnancy.
Why did problems with the water persist after Flint was reconnected with Detroit's water system?
Why did problems with the water persist after Flint was reconnected with Detroit's water system? Detroit's water system was also full of toxic particles. The old pipes were replaced by pipes that were also corroded. The water ran through corroded pipes that put toxic particles into the water.
When did Flint start adding corrosion control to the water treatment facility?
Back in 2014, Flint water treatment workers expected they'd add corrosion control to the city's drinking water -- chemicals that would that would have prevented a public health crisis -- after the city switched its water supply. But the Michigan Department of Environmental Quality said they didn't have to.
What type of bacteria was found in Flint's water?
It is later determined that the switch from Detroit water to Flint River water—which was found to have been inadequately disinfected with chlorine—caused a spike in disease-causing legionella bacteria.
How much does it cost to treat Flint River water?
Corrosion-control chemicals, which keep lead contained by coating the inside of plumbing pipes, are cheap; some reports estimate the cost of treating Flint River water at less than $150 a day. Plant upgrades, however, are expensive.
Who appointed the Flint Water Advisory Task Force?
It also drew scorn from the Flint Water Advisory Task Force, appointed by Gov. Rick Snyder himself to investigate the crisis -- the task force called MDEQ's interpretation of the rule "egregious" and "lax," saying it bypassed important and obvious questions about water safety. Tom Gores, Huntington Bank put $25M toward Flint development. ...
Why did MDEQ misinterpret the lead and copper rule?
The state has said, for months, that MDEQ misinterpreted the federal Lead and Copper Rule, a guideline for treating water to prevent the kind of public health crisis that happened in Flint -- because water pumped from the Flint River hadn't been dosed with corrosion control chemicals, the city's residents were exposed to lead-contaminated water, for almost two years, including nearly 9,000 children younger than 6.
What kind of illogic makes parsing the causes and consequence of the Flint water crisis so maddening?
It's the kind of circular, maddening illogic that makes parsing the causes and consequence of the Flint water crisis so maddening.
Why did Flint break?
And it was still broke the next year, when a different emergency emergency manager opted to pull drinking water from the Flint River while the new system was under construction, ...
Why were Flint's choices justified?
Both choices were billed as cost-saving measures, justified because of Flint's financial situation.
Who put $25M into Flint?
Tom Gores, Huntington Bank put $25M toward Flint development. But testimony at a legislative hearing this week from the city's utilities chief may help explain why: When Flint began to pump drinking water from the Flint River, the city's water treatment plant wasn't capable of adding corrosion control treatment, ...
What was the Flint River water treatment plant?
The City of Flint purchased the Flint Water Company in 1912. By 1930, Flint River water was being treated using alum coagulation before sand filtration, with the plant rated at 28 mgd (Hardin 1932). Construction on a new treatment plant for the City of Flint began in 1952 and was completed in 1954. At that point, treatment of the Flint River included prechlorination, coagulation with alum, lime-soda ash softening, recarbonation, filtration, the addition of polyphosphate for corrosion control, and postchlorination. Taste-and-odor-causing compounds were removed using activated carbon, along with the addition of ammonia and sodium chlorite. The plant was rated at a capacity of 59 mgd, with a maximum overload capacity of 86 mgd. The 50th percentile pH, color, and turbidity of the finished (tap) water were 10.3, 2, and 0.1 ppm (silica scale; approximately equivalent to 0.02 Jtu), respectively. The total and noncarbonate hardness were 86 and 49 mg/Las CaC03(calcium carbonate), respectively (Wiitala 1963).
What was the treatment for the Flint River?
At that point, treatment of the Flint River included prechlorination, coagulation with alum, lime-soda ash softening, recarbonation, filtration, the addition of polyphosphate for corrosion control, and postchlorination.
What is bromate in disinfection?
Bromate is a disinfection by-product formed by the reaction of bromide ion with ozone. Monthly bromate monitoring for the first year of operation was required by the D/DBP Rule and were ordered by MDEQ staff on Sept. 11, 2014. The first bromate sample was to be taken by the end of that month. The 2014 consumer confidence report (City of Flint 2014) states that the bromate levels varied from 0 to 23 μg/L, and that no violation occurred. However, as the reporting limit for bromate was 5 μg/L (Stark 2016), the bromate levels actually varied between <5 and 23 μg/L.
How much chlorine is needed for disinfection?
Disinfection was accomplished using gaseous chlorine which, as shown in Figure 2, was to be added both before and after filtration. The total chlorine dosage varied from ~5 mg/L in the winter months to > 7 mg/L in the summer months (Figure 5). Not surprisingly, the chlorine demand, calculated by subtracting the chlorine residual leaving the treatment plant from the applied chlorine dosage, increased during the summer and decreased during the winter. The location of chlorine application varied significantly during the treatment period, with no post-filtration chlorination until May 17, 2015, and then no prefilter chlorination after Aug. 3, 2015. No justification for these changes was documented in the MORs. The softening bypass stream had been reduced to no greater than 20% in November 2014 in an attempt to reduce chlorine demand. The minutes of the Nov. 7, 2014, TTHM Response Planning Meeting (MDEQ e-mail correspondence) state that the bypass was discontinued “and it appears that the chlorine demand has dropped by 0.5–1.0 mg/L.” However, as shown in Figure 5, this drop appears to be a part of a downward trend that occurred before this change. In summer 2015, the chlorine demand was somewhat lower than in summer 2014, but it is not clear whether this is due to eliminating the softening bypass stream or to other causes.
What is the lead level in Flint water?
In February 2015, the City of Flint sampled Flint resident Lee Ann Walters’ home and found lead in her water at a concentration of 104 μg/L (e-mail correspondence between US Environmental Protection Agency [USEPA] Region 5 and MDEQ dated Feb. 26, 2015; Flint Water Advisory Task Force 2016). By Aug. 31, 2015, Marc Edwards, a professor at Virginia Polytechnic Institute and State University, had analyzed 120 samples from Flint homes. He found that 20% of the samples had lead levels that exceeded the 15 μg/L action level and that the 90th percentile was 30 μg/L (Roy 2015a). In September, a team led by a local pediatrician, Mona Hanna-Attisha, published data showing that blood lead levels (BLLs) in children increased significantly after the switch to the Flint River as a water source (Hanna-Attisha et al. 2016; Kennedy et al. 2016). In the area of Flint that had the highest lead levels in the watei; the BLLs in children who were tested increased by a factor of about 2.5.
Why was the 24-month source water sampling not done before the switch to Flint River water?
coli, and turbidity to determine bin placement required by the SDWA Long-Term 2 Enhanced Surface Water Treatment Rule was not done before the switch to Flint River water, apparently because MDEQ staff believed the Flint River was only a temporary source (MDEQ e-mail conversations), despite the fact that construction on the 80-mi KWA pipeline had not even begun in April 2014.
What river does Flint use?
After failing to come to an agreement on a short-term contract with DWSD, Flint decided to use water from the Flint River and treat it at the FWSC. Many warnings and concerns were voiced regarding the use of the Flint River as a community water source.
What was the role of corrosion in the Flint Water Crisis?
The Role of Corrosion in the Flint Water Crisis. A decision to not add a corrosion inhibitor to the city’s treated water appears to have been a key factor in the subsequent chain of events that resulted in a public health hazard.
Why did Flint change its water source?
On April 25, 2014, city officials in Flint, Michigan, changed the city’s water source from Lake Huron (purchased from and treated by Detroit, Michigan) to the Flint River, in an effort to save money. Flint’s existing water treatment plant was reactivated as part of the cutover.
What chemicals are used to prevent corrosion in water pipelines?
To control pipeline corrosion, water treatment plants usually add a chemical corrosion inhibitor, such as phosphoric acid, polyphosphate or orthophosphate, which promote the buildup of scale to protect the water.
What happens to lead pipes after they are installed?
Shortly after lead pipes are installed, chemical reactions occur that cause a protective layer of lead scale to build up on the inside walls of the pipes (Figure 1) . This protective barrier prevents lead from leaching into the water and prevents oxidants in the water from contacting the pipe’s surface.
How many lead pipes does Flint have?
Smaller service lines carry the water to individual residences and commercial buildings. Flint has approximately 20,000 lead service pipes.
What prevents the lead atoms from entering the water that is flowing in the pipe?
In essence, the scale , which consists of lead and other minerals, prevents the pipe's lead atoms from entering the water that is flowing in the pipe. Figure 1. Inside section of pipe with scale build up.
How much lead is in tap water?
Lead was discovered in the tap water after continued citizen complaints to city officials, and tests at some residences revealed a lead content of 104 ppb. In comparison, the US Environmental Protection Agency (EPA) allowable maximum is 15 ppb.
Why is the Flint water problem so intractable?
The problems became intractable in Flint due to the excessive corrosion of the pipes that deliver water to people’s homes.
How much money did Flint save by not adding a corrosion inhibitor?
By not adding a corrosion inhibitor, Flint was going to save about $140 per day. But the inestimable costs of the errors made in Flint will reverberate through the community for a long time and their magnitude will dwarf the original planned savings.
Why is coagulant choice important?
Coagulant choice is an important design decision; therefore the choice of coagulant should not be based only on cost. For example, each coagulant has to be optimized to enhance removal of natural organic matter in the source water. If too little organic matter is removed, it will react with chlorine disinfectants in the water to form hazardous by-products.
What are the problems with the Flint River?
Because of Flint’s method of treating Flint River water, it experienced problems with elevated trihalomethanes, a regulated class of disinfection by-products that are known carcinogens. A domino series of causes and effects were responsible for this problem.
What causes turbid water in iron pipes?
In iron pipe systems, the released iron corrosion particles are visible, causing colored and turbid water. In older distribution systems, where lead service lines are often still in place, corrosion then releases lead and copper. Corrosion rates can be affected by many factors that are not well-understood, including the presence of bacteria that colonize the pipe wall, as well as pipe age and water flow rates.
How long does it take to design a water disinfection system?
As a researcher on water disinfection and professor of civil and environmental engineering, I know that a planning period of at least two to three years to get to a ribbon-cutting for such a facility is normal. The design of these systems is iterative by its nature and requires input from multiple stakeholders at various points in the design process.
Why did chlorine levels spike?
Because chlorine, which reacted with the iron pipes, could not act as as disinfectant, bacteria levels spiked. When coliform bacteria were detected in distribution system water samples, water utility managers were obliged by law to increase the levels of chlorine. The higher levels of chlorine, while reducing coliform counts, led to the formation of more trihalomethanes.
Why did Flint change its water source?
In early 2013, in order to save money , Flint officials decided to change the source of the city’s water from the Detroit Water and Sewerage Department to the Karegnondi Water Authority (KWA). However, KWA was not ready to deliver the water, because they were in the process of building a new pipeline to bring water from nearby Lake Huron. This meant that officials in the city of Flint needed to find a short-term solution while the new pipeline was being built. They decided to use water from the local Flint River that they would clean in water treatment plants.
Who appointed the Flint Water Task Force?
March 2016: The Flint water task force, appointed by Governor Snyder, finds that state agencies within Michigan are mainly responsible for the crisis.
How to prevent lead from leaching into water?
One method is to create a protective layer on the inside of the pipe. This is done by adding phosphate ions (PO 43–) to the water supply. Phosphate is also known as orthophosphate.
What are the chemicals in water?
Trihalomethanes are just one group of chemicals associated with water contamination, lead is another. Lead was a popular choice for use as water pipes for centuries. The Romans used the dense metal because of its durability and malleability. Water pipes are no longer made from lead, but older cities, such as Flint, still rely on lead pipes—in addition to those made from copper and iron—to transport water to people’s homes. No one knows exactly how many lead pipes are used in the United States, but the number is in the millions. In addition to the pipes themselves, lead is also found in alloys (mixtures of metals) in other parts of the plumbing system. For example, the solder used to join pipes together is an alloy of tin and lead.
Why are trihalomethanes dangerous?
Trihalomethanes are a concern because they have been linked with numerous health concerns, including liver, kidney, lung, and heart problems. When the chorine used to disinfect water reacts with algae, leaves, and weeds, trihalomethanes are produced.
Why is the Flint River water so high?
First, the Flint River water had some unusually high levels of chloride ions, which can accelerate the corrosion of the pipes. In part, these high chloride levels came from salts used to treat roads during the cold and snowy Michigan winters. Often, chlorides enter rivers as run-off from the roads.
What are the three atoms in Flint water?
These molecules are similar to methane molecules (CH 4 ), but three of the hydrogen atoms are replaced with halogen (group 17) atoms—fluorine, chlorine, bromine, or iodine.