A lead service line (LSL, also known as lead service pipe, and lead connection pipe) is a pipe made of lead which is used in potable water distribution to connect a water main to a user's premises. Lead exposure is a public health hazard as it causes developmental effects in fetuses, infants, and young children. It also has other health effects in adults. According to the World Health Organization, the presence of lead service lines is the most significant contributor of lead contamination in drinking water in many countries. The most certain way to eliminate lead exposure in drinking water from the lead service lines is to replace them with pipes made from other materials. However, replacement is time-consuming and costly. The difficulty is exacerbated in many locations by ownership structure with a shared responsibility between water utilities and property owners, which requires cooperation between the two entities. Some water utilities employ corrosion control as a short-term solution while working through long-term replacement projects. A potential issue with corrosion control is constant monitoring of its effectiveness. There have been widespread lead exposures resulting from failures of corrosion control, such as the Flint water crisis.
Background Lead had been associated with plumbing since the ancient times. The chemical symbol for lead (Pb) is derived from the Latin word plumbum, which means 'waterworks' or 'plumbing' as lead was used to make water pipes. Lead water lines have also been known to be harmful since ancient times, though this is contested by industry trade groups within the United States. Lead pipes were preferred over iron pipes because they lasted longer and were more flexible.
In modern times, lead was still widely used in water distribution systems and plumbing hardware before the early 20th century, including lead pipes, leaded solder and leaded alloys. One part of the system is the connections between the water mains and the water user locations. A service line is a pipe that makes the connection, which was also made of lead in those days. The first portion of the service line is called a gooseneck, which connects to a valve at the water main and is required to be flexible to allow some movement. Lead goosenecks (also called lead service connections or LSCs) were commonly used in the past due to their durability and flexibility. In colder-weather areas, the connection between the water main and the rest of the service line is subjected to expansion and contraction during temperature changes. When stiffer service lines made of galvanized steel pipe were used, lead goosenecks were installed to connect to the water main to reduce breakage from such expansion and contraction. From the mid-1800s to the early 1900s, many communities started to realize the health risks of lead and began to phase out some lead-containing products. In Australia, the use of lead service lines was restricted in the 1930s, while other countries still continued the practice of using lead service lines decades later. An example is the United States, where lead service lines were allowed until the 1980s. Not only were they allowed, but some parts of the United States mandated the use of lead service lines until 1987, primarily due to lobbying by lead manufacturers and plumbing unions. This resulted in as many as 3.3 million lead service lines and 6.4 million lead goosenecks in the country. In England and Wales, there were about 8.9 million homes with lead service lines as of 1997. In the 2010s, one-third of American communities still had lead service lines, with an estimate of up to six million. Elimination has been extremely difficult due to the high cost of identifying, locating, removing, and preventing the many potential sources of lead in various water distribution systems in the United States.
Health effects
Lead exposure, even at low levels, can cause neurological effects, especially in young children, young women, and developing fetuses. In fetuses, lead in the mother's bones is released along with calcium during fetal bone formation. Lead can also cross the placental barrier into the fetus, which can cause premature birth, growth issues, and death of the fetus. Lead can be passed from the mother through breastfeeding. In children, the effects of lead exposure include learning problems, slow growth, and lower IQ. In adults, low-level exposure can cause hypertension, cognitive issues, and reproductive harm.
Regulations The World Health Organization (WHO) published the first edition of Guidelines for Drinking-water Quality (GDWQ) in 1984 to replace the 1970 European Standards for Drinking-Water and 1971 International Standards for Drinking-Water. The publication recommended the limits of contaminants in drinking water which set the value for lead to not more than 0.05 mg/L based on assumptions about various sources of lead intake and the provisional tolerable weekly intake of 3 mg of lead per adult that was established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in 1972. However, no safe levels had been defined. In 1986, JECFA updated the provisional tolerable weekly intake level of lead for infants and children to be based on body weight, at 25 micrograms of lead per kilogram of body weight. JECFA reconfirmed this provisional tolerable value and extended the same value to all age groups in 1993. When WHO published the second edition of GDWQ in 1996, it based it on the new JECFA value assuming 50% of lead exposure from drinking water and a 5-kg infant consuming 0.75 liters of water from bottles per day, and infants are in the most sensitive subgroup. Therefore, WHO established the guideline value of lead concentration in drinking water not to exceed 0.01 mg/L.
Argentina As of early 2020 Argentina has set a standard of 0.05 mg/L based on Resolution no. 523/95-MTSS, which is an amendment of law 19587.
Australia In 2004, Australia lowered the lead exposure limit to 0.01 mg/L from 0.05 through the 2004 Australian Drinking Water Guidelines. However, this is a guideline, not a mandatory standard.
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