Lead poisoning has become synonymous with the name of Flint, Michigan. While lead poisoning is not a new problem, the Flint crisis definitely helped the latent matter reach the national forefront, and rightly so, because addressing the problem is key to securing healthy body and brains for the next generation.
The Use of Lead Pipes in Infrastructure
Lead poisoning affects kids more than adults because their bodies absorb lead faster and better, resulting in children with lower intelligence levels, not to mention other problems such as learning disabilities, seizures etc. Since lead is one of the oldest plumbing materials in use, a lot of our city water infrastructure is bound to have been produced using lead pipelines. The problem is now to ascertain where these pipelines are, and to replace them before another crisis like Flint forces us out of our stupor.
As much as 70% of cities in the United States were using lead pipes for conveying potable water in the 1900’s, and since then, it has been well known that lead is poisonous. It is easy to replace the lead pipes above ground, like those within homes, but finding and replacing lead pipes underneath should be a priority. While digging up an entire stretch of road, disrupting and uprooting an entire city to replace these pipes is not possible, trenchless rehabilitation methods have brought much relief by way of eliminating the need to dig up anything at all using open trenching. Many methods like cured-in-place pipe (CIPP), sliplining, pipe bursting, pipe pulling, etc. have revolutionized the underground rehabilitation industry.
Dangers of Lead Contamination
Ironically, lead has been known as being poisonous to humans and other species since the era of the Roman, since they were the first to use lead pipes for their plumbing needs. Lead is cheap, and making lead pipes was cost-effective because it is stable and can be easily molded; however, the effects of lead on the health of the Roman people was evident to them.
Like we all know by now, humans react to a crisis only when it gets out of hand, and so it was with Flint. According to Harold Babbitt, a professor of Sanitary Engineering, lead is quite soluble in water, hence its use in the supply of potable water should at least be restricted. The Massachusetts State Board of Health has conducted tests that show lead contents up to 3 to 5 parts per million (ppm) in water, which is quite high, but an increase in lead content from 50 to 100% when that water has been standing in lead pipes. Surprisingly, a content of 0.5 ppm is considered dangerous to health.
Lead can affect systems in the body in adults, but more so in young children, because when lead enters the body, it is distributed to the liver, kidney, bones, and even to the brain.
Lead Exposure During Pregnancy
It has been found that lead present in an expectant mother’s blood can cause exposure to the fetus. Lead contamination can cause miscarriage, premature birth, minor malformations in the baby, and even stillbirth.
Lead Exposure in Children
Children exposed to lead contamination can be effected in permanent ways by affecting the development of the brain and nervous system because they absorb 4-5 times more than adults would.
Lead Exposure in Adults
Adults experience high blood pressure, kidney damage, increased risk of stroke and cancer, brain damage etc. To prevent this damage, lead has to be eliminated from our water supply system. To do this, the pipes need to be replaced by either traditional or Trenchless methods.
Trenchless Technology to Replace Lead Pipes
With miles of pipes running under our feet, it will be a nightmare to find and replace lead pipes in our cities. However; thanks to trenchless technology, many cities have successfully replaced their lead pipes using trenchless rehabilitation methods with minimal disruption to vehicles, pedestrians, and homeowners.
Here are a few examples of cities that have adopted trenchless rehabilitation methods to replace their lead pipes.
Toronto, Ontario, Canada 2007
The City of Toronto Council approved a lead water service replacement program in 2007 to replace over 65,000 lead water services over the next nine years. They opted to use trenchless rehabilitation methods to carry out this large scope of work. It helped them prevent unnecessary work by identifying 353 services that had already been upgraded but not recorded in the city database and discovered and replaced 238 lead connections that had not been identified. (More in "Rehabilitating City Water Lines Using Trenchless Technology.")
Saskatoon, Saskatchewan, Canada
The City of Saskatoon has approved a lead water pipe replacement initiative this year that will see the replacement of over 900 lead pipe services connecting homes and offices.
Holland, Netherlands
Holland has been replacing its lead water pipes for some years now using the traditional open trench method. Pipe pulling using trenchless technology was later adopted because the open trench method was causing a lot of disruption on the surface to road users and homeowners. The trenchless method proved to be a success and also time and cost-efficient.
Methods of Lead Pipe Replacement
Old and deteriorated pipes can be easily replaced or repaired depending on the extent of the damage. Since lead water pipes are known to cause lead poisoning in adults and children, it is necessary that these pipes are replaced.
Some excellent methods to repair lead pipes are CIPP, sliplining and pipe bursting.
Cured-In-Place Pipe
CIPP involves using a liner soaked with a resin prior to installation. It is designed to fit the size of the host pipe and is usually made of fiber reinforced fabric or non-woven polyester. The liner is inserted into the host pipe and expanded until it fits the pipe diameter. (Find out more in "Why CIPP Is Growing Rapidly for Drinking Water Mains.")
Hot compressed air or steam is used to cure and set the liner in place. CIPP-lined pipes make the host pipe as good as new and increase the lifespan of the pipe to many decades.
Sliplining
Sliplining involves slipping a smaller diameter pipe within the host pipe and sealing the annular spaces and ends with grout. (Learn more in "Sliplining or Pipe Bursting for Pipe Repair?.")
Though the original flow is marginally reduced, this method improves flow characteristics because of the use of materials such as high density polyethylene (HDPE), fiber reinforced plastic (FRP) and polyvinyl chloride (PVC), which possess qualities that prevent the buildup of material on the inside surface, and are resistant to corrosion and abrasion from chemicals and solid particles that may be present in the flow.
Pipe Bursting
Pipe bursting literally means bursting the pipe. A conical bursting head slightly larger than the diameter of the host pipe is inserted and pulled through the pipe. A new pipe made of materials such as HDPE and PVC, slightly smaller than the diameter of the bursting head is pulled in behind it. (Read on in "An Introduction to Pipe Bursting.")
As the bursting head shatters the host pipe, in a process known as fragmentation, with its rotation, the fragments are pushed into the soil surrounding the pipe, and the new pipe is installed simultaneously.
Trenchless Technology and rehabilitation methods can be a cheaper alternative to replacing hazardous plumbing materials such as lead pipes and asbestos-laced pipes. Over time, cities are opting for the more nondisruptive methods. (Learn more in "Asbestos Cement Pipe: Why It's a Problem and How Trenchless Can Fix It.")