There’s More to Infrastructure Than Meets the Eye
By Rika Lashley, PE
What do you think of when you hear “infrastructure?” Streets, bridges, railroads, electricity? All things we see every day – on the way to work, to school, when waiting at a railroad crossing. It is quite obvious when asphalt cracks and potholes develop and we want to call the city or county and ask them to fix it.
However, there is more to infrastructure than what quite literally meets the eye. We tend to be rather oblivious to the infrastructure a few feet below the wheels of our cars: the water distribution and sewer collection systems that supply us with clean safe water and convey our (mostly) liquid waste away from our homes. Of course the piping is not all – in many communities the clean water comes from water treatment plants that supply enough treated, disinfected, safe water to allow us to drink, cook, wash, and water our yards at the turn of a faucet day after day. In addition, wastewater treatment plants treat our wastewater until it is safe to be discharged to our rivers, streams, groundwater, or for watering crops, while protecting our water resources so they will be available for downstream and future users.
All this infrastructure is largely out of sight and out of mind. It is only when something goes wrong that we notice as was the case in Flint, Michigan. The very unfortunate events there awakened the entire nation to the fact that we must be aware of our buried infrastructure, that in many places piping systems are very old and require repair or replacement in order to be able to continue to deliver safe drinking water. In Flint, a series of bad decisions exacerbated things to the point of causing serious and possibly lasting health issues. When water infrastructure fails, there may be immediate and serious health threats to consumers. When wastewater infrastructure fails, in addition to human health, the health of the environment may be threatened. Therefore it is so important that infrastructure is updated before water quality disasters happen. Just as we would like bridges to be repaired before they fall down.
In the Flint catastrophe, lead service lines played a large role. Service lines are the small diameter water lines that connect homes to the water mains. These pipes may be owned by the municipality or water utility where they are in public right of way and by private property owners where they are located within the property boundaries or they may be owned by the homeowners in their entirety.
Prior to Flint, many of us were not aware that until the 1970s lead pipe was used for many of these services. An article published in the April 2016 issue of Journal AWWA (Vol. 108 No.4) presented the findings of two surveys of U.S. community water systems that were conducted to gather information on lead-containing service lines. According to the survey, Montana and Wyoming are among the states with the fewest reported lead service lines. However, most of those that do exist are likely located in communities with populations of less than 10,000. The article may be accessed here.
The dangers of lead service lines are typically mitigated by providing treated drinking water with corrosion control additives. In addition, a protective film made of deposits of various minerals can form on the inside of the pipe and act as a protective lining, limiting the amount of lead that can leach into the water as it passes.
Ultimately, replacing the lead piping with safer materials would be the best protection from lead in drinking water. Where service lines are on private property, it falls to the property owner to replace the line.
If you find that you have a lead service line and decide to replace it, it is important that you work with your water utility because the portion that is within the public right of way may also be lead pipe and should be replaced at the same time. Replacing only a portion of the service line may be more detrimental than leaving it in place.
More information on lead service lines can be found on the American Water Works Association website . If you’d like more information or to ask questions, please contact me directly.
Rika Lashley, PE is a water-wastewater engineer who works in Morrison-Maierle’s Helena office. Her 14 years of experience include planning, design, and construction of water and wastewater conveyance and treatment systems. She is particularly passionate about wastewater process design and analysis and troubleshooting of existing treatment systems.