Car Tires Polluting our waterways

Thats In My Water Blog

Have you ever thought about what happens to the tiny particles that wear off your car tires as you drive? I hadn’t either—until I listened to The Civil Engineering Podcast (Episode 280: Powerful Strategies for Stormwater Management with Green Infrastructure). In this episode, guest Craig Buitrago mentioned a surprising study from Washington State University that uncovered a hidden pollutant lurking in our everyday lives. It turns out that a chemical used in tires, 6PPD-Quinone, is making its way into our waterways—and it’s proving deadly to fish.

Understanding 6PPD-Quinone: The Hidden Pollutant from Tire Wear 

In recent years, environmental scientists have identified a previously unrecognized pollutant: 6PPD-quinone. This chemical, derived from a common tire additive, has been linked to significant environmental concerns, particularly affecting aquatic life. 

What is 6PPD-Quinone? 

Tires are manufactured with various chemicals to enhance their durability and performance. One such additive is 6PPD (N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine), which serves as an antiozonant, protecting tires from degradation caused by ozone exposure. However, when 6PPD reacts with ozone in the environment, it transforms into 6PPD-quinone. This transformation occurs as tires wear down during regular use, releasing particles that contain 6PPD-quinone onto road surfaces. Subsequent rainfall washes these particles into waterways, introducing the chemical into aquatic ecosystems.   EPA.GOV

Key Findings from Recent Studies 

  1. Impact on Coho Salmon 

A groundbreaking study in 2020 uncovered that 6PPD-quinone is highly toxic to coho salmon. Researchers observed that even minimal exposure to this chemical in urban runoff led to acute mortality in these fish before they could spawn. This phenomenon, termed Urban Runoff Mortality Syndrome, has raised alarms about the survival of coho salmon populations in urbanized regions.  SCIENCE.ORG

  1. Broader Ecological Implications 

Further research has indicated that the toxic effects of 6PPD-quinone are not limited to coho salmon. Other species, such as brook trout and rainbow trout, also exhibit sensitivity to this pollutant, though the degree varies among species. The exact mechanisms underlying this species-specific toxicity remain under investigation, but the findings suggest that 6PPD-quinone poses a widespread threat to aquatic biodiversity.  EN.WIKIPEDIA.ORG

  1. Environmental Persistence and Distribution 

Studies have detected 6PPD-quinone in various environmental compartments, including urban waterways, estuaries, and even deep-sea regions. Its presence in such diverse habitats indicates its persistence and mobility, raising concerns about long-term ecological impacts. Factors such as temperature, light exposure, and storm events influence its distribution and transformation in the environment. PUBMED.NVBI.NLM.NIH.GOV

Consequences of Inaction 

If the release of 6PPD-quinone into the environment continues unchecked, several adverse outcomes are anticipated: 

  • Decline in Fish Populations: Species like coho salmon, which are already facing numerous challenges, could experience further population declines, disrupting ecosystems and affecting species that rely on them for food. 
  • Ecosystem Imbalance: The loss of key species can lead to cascading effects throughout the food web, potentially resulting in the overpopulation of some organisms and the decline of others. 
  • Cultural and Economic Impacts: Communities that depend on fishing for their livelihoods, cultural practices, or subsistence could suffer significant losses. For instance, many Indigenous tribes in the Pacific Northwest have deep-rooted cultural ties to salmon fishing.  MAKINGWAVES.PSP.WA.GOV

Mitigation Strategies 

Addressing the challenges posed by 6PPD-quinone requires a multifaceted approach: 

  1. Green Infrastructure Implementation 

Techniques such as bioretention systems, which use soil and plants to filter pollutants from stormwater, have shown promise in removing contaminants like 6PPD-quinone. By capturing and treating runoff at its source, these systems can prevent harmful substances from reaching aquatic habitats. 6PPD.ITRCWEB.ORG

  1. Permeable Pavements 

Research indicates that permeable pavements can trap tire wear particles, reducing the amount of 6PPD-quinone entering stormwater systems. These pavements allow water to infiltrate through their surface, filtering out pollutants in the process. STORMWATER.COM

  1. Development of Safer Tire Additives 

Collaborative efforts between scientists, industry stakeholders, and regulatory bodies are underway to identify and promote alternatives to 6PPD that do not produce toxic byproducts. This proactive approach aims to prevent pollution at its source by redesigning products with environmental safety in mind. 6PPD.ITRCWEB.ORG

Current Initiatives 

Several organizations and communities are actively working to combat the effects of 6PPD-quinone: 

  • Washington State Department of Ecology: Collaborating with tribal governments, local agencies, and research institutions, this department is spearheading efforts to monitor 6PPD-quinone levels and implement effective stormwater management practices. ECOLOGY.WA.GOV
  • The Nature Conservancy: This environmental organization is advocating for the use of green infrastructure to address stormwater pollution. Their research suggests that strategically placed bioretention systems could significantly reduce pollution in critical areas.  NATURE.ORG
  • U.S. Environmental Protection Agency (EPA): The EPA is conducting research to better understand the environmental prevalence, fate, and bioavailability of 6PPD-quinone, aiming to inform regulatory decisions and mitigation strategies. EPA.GOV

Conclusion 

The discovery of 6PPD-quinone’s toxic effects underscores the complex challenges posed by modern pollutants. Through collaborative research, innovative infrastructure solutions, and proactive policy measures, it is possible to mitigate the impact of this chemical, safeguarding both aquatic ecosystems and the communities that depend on them. 

Lead In Our Drinking Water

Thats In My Water Blog,

Originally this piece was going to be about the tap water issues in Flint, Michigan.   It turns out the subject is a political hot potato with plenty of blame to be spread around.  This is not the place to have that discussion.   Curiosity got the best of me because there was lead in the water.  Where did the lead come from?  This is where we will depart from the problems in Flint.

Lead (pb) is extremely harmful to our bodies.  Lead contamination leads to nerve and brain damage.  In general, women are more susceptible than men to lead poisoning.  Fetuses are more susceptible to lead poisoning than their mothers, fetuses will actually protect the mothers from lead poisoning.  Lead causes infertility and spontaneous abortion.   Lead is just something that is bad in our bodies.

So where is the lead coming from?  From our lakes and rivers, lead is coming from our streets, pipes and soils.  This is a very insignificant amount and is in general not the cause of lead poisoning.  Drinking water standards in the United States allow for zero amount of lead in drinking water leaving the treatment plants.  So if the sources of tap water for cities are rivers, lakes or ground water and it is treated before it leaves the plant, the lead pollutant is getting into the water between the water plant and our faucets.   So that means our plumbing is the culprit.

Lead service lines are the major source of the lead pollutant in our drinking water.   Fortunately lead lines were phased out in the 70’s and 80’s.  Lead pipes were installed for use in Chicago as late as 1986.  The problem is when pipes come in contact with water and oxygen, a layer of lead oxide forms on the inside surface of the pipe.  This layer forms to protect the pipe from further corrosion.   Over time water flowing through the lead pipe dissolves the lead and then ends up in out tap water.

Seems like a pretty simple and easy fix.  Get rid of all the lead piping!  It’s not that simple.  There’s a thing called economics.  It would be pretty tough to explain to a neighborhood that their taxes are going up again for a second straight year because last year’s new water lines need to be replaced with new copper water lines this year, and oh by the way you may have been poisoned.

Enter the 1991 Lead and Copper Rule, a regulation designed to protect Americans from the nation’s aging lead service lines.  The regulation required utilities to test water from local homes for lead.  If 10% of the samples exceeded 15 parts per billion, the utility was ordered to reduce the lead by chemical corrosion means.  If that failed, water utilities had to replace 7% of their lines each year or until follow-up samples showed a reduction in lead levels.  Seems like a reasonable fix, service lines are replaced or lead levels meet standards. Problem solved.

Problem solved?  Not so fast.  Chemists, these guys were not, who wrote the Lead and Copper Rule.  When the new copper lines are connected to old lead lines using brass fittings a galvanic corrosion is initiated and that can greatly increase the amount of lead entering into the water.  Lab experiments have shown copper lead pipe connections can release up to five times more than just the lead pipe alone.  When replacing the lead lines the utilities can’t replace the home owner’s line unless they give the go ahead and pay for the new line going to the house.  Well, who would not want a new line to the house and eliminate the potential for lead poisoning.  Apparently 90% of American households said they were just fine with the old lead pipes.  So maybe it really was not explained very well and also again economics were in play.  Replacing the homeowner’s portion of pipe, from property line to house, is expensive.  Cost can run from $2500 to $7000.00 or more depending on circumstances.   That is a major chunk of change for most home owners.  So it is safe to assume that there are a lot of lead-copper connections in older neighborhoods throughout the country.

It gets better yet.  There are two ways of chlorinating water to disinfect it. Utilities either use free chlorine or chloramines.  Chlorine forms higher concentrations of disinfectant byproducts that are not wanted in the drinking water.  The switch to chloramines then reduces the disinfectant byproducts.  This is good right.  It would seem there would be less pollutants in the water, however again chemistry comes into play.  Lead has different oxidation states.  Without going into a lot of chemistry when utilities use the free chlorine which is a strong oxidant the lead pipes are fairly stable, upon switching to chloramines not as strong an oxidant, the lead goes to a different oxidation state and become soluble.  So pipe scale that has been built up over the years in now release into water stream.

Chemistry, Chemistry, Chemistry.  The water source of the utilities also plays an important role, dissolution rates of lead are a function of pH.   A lower pH level will be more corrosive to the pipes. The pH varies from source to source.  In the case of Flint, Michigan, the Flint River has a lower pH than the treated water from Detroit.  If the Flint utilities did not increase the pH to that of the Detroit supplied water an increase of corrosion in the pipes would have happened.  Also if Flint utilities used a different disinfectant than the Detroit utilities problems could have happened too.

In the end, there is more to our drinking water supply than meets the eye.  It is like anything else we purchase for our homes, a manufactured product.

Don’t Sunbathe Here

Articles, Thats In My Water Blog

Setting out to find information on stormwater inlet protection devices, which by the way is very boring and tedious, led me to a very interesting article.  The article caught my attention because of the title of the article, “Who built a beach on a stormwater pond?”

Photo by Mitch Haustein
Photo by Mitch Haustein

The article discussed a method of effectively removing some of the phosphorus out of the stormwater before it enters into a lake.  Phosphorus, in high amounts, is a nutrient when entering a body of water can cause an unsightly algae blooms and is detrimental to aquatic life because algae blooms  deplete the oxygen in the water column.

Continue reading Don’t Sunbathe Here →