Lead and copper rule
Encyclopedia
The "Lead and Copper Rule", or LCR, is a United States federal regulation
which limits the concentration of lead
and copper
allowed in public drinking water
at the consumer's tap, as well limiting the permissible amount of pipe corrosion
occurring due to the water itself. The U.S. Environmental Protection Agency (EPA) first issued the rule in 1991 pursuant to the Safe Drinking Water Act
. EPA promulgated the regulations following studies that concluded that copper
and lead
have an adverse effect
on individuals. The LCR sought to therefore limit the levels of these metals in water through improving water treatment centers, determining copper and lead levels for customers who use lead plumbing parts, and eliminating the water source as a source of lead and copper. If the lead and copper levels exceed the "action levels", water suppliers are required to educate their consumers on how to reduce exposure to lead. A 2004-2005 study of the LCR by EPA noted that the system had been effective in 96 percent of systems serving at least 3,300 people.
EPA has stated that the LCR has reduced exposure to lead "that can cause damage to brain, red blood cells, and kidneys, especially for young children and pregnant women." It also explained that the rule has reduced copper exposure "that can cause stomach and intestinal distress, liver or kidney damage, and complications of Wilson’s disease in genetically predisposed people."
is a known poison, the mechanical and chemical characteristics of the metal continue to keep lead as an important component in many products. In water supply, lead's durability and workability selected it for use as water pipes. Lead alloy
s (bronze
, brass
) are used for plumbing
fittings. Lead solder
s were preferred in plumbing
. While lead pipes were replaced by other materials, such as plastics, early in the twentieth century, lead alloys continued to be used. Although new lead pipes weren't installed later in the 20th century, some existing lead pipes remain in service in many cities.
The U.S. Public Health Service published a non-enforceable standard for lead in 1925, consisting of a tolerance limit of 0.1 mg/L
.
Partially because of lead pipes, some states regulated the corrosivity of water put into the distribution system. Waters which would deposit a protective coating on the pipes rather than dissolving the pipe were preferred. Corrosion indexes such as pH
or Langelier Saturation Index are not necessarily representative of the lead corrosion potential in a particular water/pipe system, nor did they measure the amount of lead to which customers were exposed.
In the second half of the twentieth century, concern was growing about what constituted a safe level of lead
.
The 1986 Safe Drinking Water Act
amendments defined "lead-free" plumbing and prohibited the use of plumbing for public water supply that did not meet the new definition. The amendments also required EPA to set standards limiting the concentration of lead in public water system
s.
Following the adoption of the 1991 rule, public water systems serving more than 50,000 people were required to survey their own corrosion control systems and to replace their pipelines with state-approved corrosion control by January 1, 1997. Suppliers who served a smaller number of people only had to replace their pipelines if action levels were exceeded at the tap.
EPA published the Lead and Copper Rule Minor Revisions (LCRMR) in January 2000. This rule required water suppliers to install the best available corrosion control mechanisms and to continually observe water levels, even if corrosion control was implemented. The revisions were effective April 11, 2000.
Additional corrections and minor revisions were made in 2004 and 2006.
The action level for lead is 0.015 mg/L. The action level for copper is 1.3 mg/L. Water suppliers must monitor locations as specified in the rule. If the 90th percentile
value of all the samples exceeds the action level, action must be taken. Actions may include investigation, recommendation of treatment, installation of treatment, checking of source water, removal of lead containing plumbing, and public education.
Since most of the lead found in drinking water leaches from the customer's pipes, fittings, and solder rather than from the source water, special sampling is necessary. Although the chemistry is complicated, the lead dissolved in the water generally increases with the amount of time the water has been in contact with the pipe. "First draw" samples must be water which has stood motionless for at least six hours.
The site selection process prioritizes sites by the likelihood of finding high lead concentrations which could impact people. Building codes and building records may be used to estimate the types of plumbing and solders at various buildings. Residential buildings are preferred over commercial. Only taps from which water is consumed are tested. The age of plumbing is taken into account, as older piping may reach an equilibrium with the water.
While MCLs are risk-based, and the code requires the water supply take various actions based on the MCL, the lead and copper rule regulates the level of contamination at the customers' taps based on "action levels." No MCL is set for lead or copper. This method allows some percentage of the customer taps to exceed the "action level" without the water system having to take action. Especially for the larger systems, having the water supplier change the tendency of the water to dissolve lead in the customer plumbing may be more cost effective than having thousands of customers replace plumbing.
Also, because the source of lead and copper is the customer plumbing, lead and copper sampling is specified to be "first draw."
Most other water samples are taken by the water supplier's personnel. Trained personnel using consistent procedures generally yield more reliable data. The first draw sampling procedures make water supplier sampling impractical. Rather than have a technician spend six hours in a customer's home, the water supplier may leave the sample bottles and sampling instructions with the consumer.
(GAO) in 2003 following the discovery of higher-than-acceptable copper and lead levels in tap water in the District of Columbia. The GAO reported that EPA had not been collecting copper and lead levels from the states, despite claims that the levels of copper and lead have decreased; data for 72 percent of water systems were missing. EPA may have been lacking data because more resources were being dedicated to lead regulation than lead reporting.
Regulation
Regulation is administrative legislation that constitutes or constrains rights and allocates responsibilities. It can be distinguished from primary legislation on the one hand and judge-made law on the other...
which limits the concentration of lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
and copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
allowed in public drinking water
Drinking water
Drinking water or potable water is water pure enough to be consumed or used with low risk of immediate or long term harm. In most developed countries, the water supplied to households, commerce and industry is all of drinking water standard, even though only a very small proportion is actually...
at the consumer's tap, as well limiting the permissible amount of pipe corrosion
Corrosion
Corrosion is the disintegration of an engineered material into its constituent atoms due to chemical reactions with its surroundings. In the most common use of the word, this means electrochemical oxidation of metals in reaction with an oxidant such as oxygen...
occurring due to the water itself. The U.S. Environmental Protection Agency (EPA) first issued the rule in 1991 pursuant to the Safe Drinking Water Act
Safe Drinking Water Act
The Safe Drinking Water Act is the principle federal law in the United States intended to ensure safe drinking water for the public. Pursuant to the act, the Environmental Protection Agency is required to set standards for drinking water quality and oversee all states, localities, and water...
. EPA promulgated the regulations following studies that concluded that copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
and lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
have an adverse effect
Lead poisoning
Lead poisoning is a medical condition caused by increased levels of the heavy metal lead in the body. Lead interferes with a variety of body processes and is toxic to many organs and tissues including the heart, bones, intestines, kidneys, and reproductive and nervous systems...
on individuals. The LCR sought to therefore limit the levels of these metals in water through improving water treatment centers, determining copper and lead levels for customers who use lead plumbing parts, and eliminating the water source as a source of lead and copper. If the lead and copper levels exceed the "action levels", water suppliers are required to educate their consumers on how to reduce exposure to lead. A 2004-2005 study of the LCR by EPA noted that the system had been effective in 96 percent of systems serving at least 3,300 people.
EPA has stated that the LCR has reduced exposure to lead "that can cause damage to brain, red blood cells, and kidneys, especially for young children and pregnant women." It also explained that the rule has reduced copper exposure "that can cause stomach and intestinal distress, liver or kidney damage, and complications of Wilson’s disease in genetically predisposed people."
Background
Although leadLead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
is a known poison, the mechanical and chemical characteristics of the metal continue to keep lead as an important component in many products. In water supply, lead's durability and workability selected it for use as water pipes. Lead alloy
Alloy
An alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...
s (bronze
Bronze
Bronze is a metal alloy consisting primarily of copper, usually with tin as the main additive. It is hard and brittle, and it was particularly significant in antiquity, so much so that the Bronze Age was named after the metal...
, brass
Brass
Brass is an alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties.In comparison, bronze is principally an alloy of copper and tin...
) are used for plumbing
Plumbing
Plumbing is the system of pipes and drains installed in a building for the distribution of potable drinking water and the removal of waterborne wastes, and the skilled trade of working with pipes, tubing and plumbing fixtures in such systems. A plumber is someone who installs or repairs piping...
fittings. Lead solder
Solder
Solder is a fusible metal alloy used to join together metal workpieces and having a melting point below that of the workpiece.Soft solder is what is most often thought of when solder or soldering are mentioned and it typically has a melting range of . It is commonly used in electronics and...
s were preferred in plumbing
Plumbing
Plumbing is the system of pipes and drains installed in a building for the distribution of potable drinking water and the removal of waterborne wastes, and the skilled trade of working with pipes, tubing and plumbing fixtures in such systems. A plumber is someone who installs or repairs piping...
. While lead pipes were replaced by other materials, such as plastics, early in the twentieth century, lead alloys continued to be used. Although new lead pipes weren't installed later in the 20th century, some existing lead pipes remain in service in many cities.
The U.S. Public Health Service published a non-enforceable standard for lead in 1925, consisting of a tolerance limit of 0.1 mg/L
Litér
- External links :*...
.
Partially because of lead pipes, some states regulated the corrosivity of water put into the distribution system. Waters which would deposit a protective coating on the pipes rather than dissolving the pipe were preferred. Corrosion indexes such as pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
or Langelier Saturation Index are not necessarily representative of the lead corrosion potential in a particular water/pipe system, nor did they measure the amount of lead to which customers were exposed.
In the second half of the twentieth century, concern was growing about what constituted a safe level of lead
Lead poisoning
Lead poisoning is a medical condition caused by increased levels of the heavy metal lead in the body. Lead interferes with a variety of body processes and is toxic to many organs and tissues including the heart, bones, intestines, kidneys, and reproductive and nervous systems...
.
The 1986 Safe Drinking Water Act
Safe Drinking Water Act
The Safe Drinking Water Act is the principle federal law in the United States intended to ensure safe drinking water for the public. Pursuant to the act, the Environmental Protection Agency is required to set standards for drinking water quality and oversee all states, localities, and water...
amendments defined "lead-free" plumbing and prohibited the use of plumbing for public water supply that did not meet the new definition. The amendments also required EPA to set standards limiting the concentration of lead in public water system
Public water system
The US Safe Drinking Water Act and derivative legislation define public water system as an entity that provides "water for human consumption through pipes or other constructed conveyances to at least 15 service connections or serves an average of at least 25 people for at least 60 days a year."The...
s.
Adoption
EPA first issued the lead and copper rule on June 7, 1991. The latest modification was issued October 10, 2007.Following the adoption of the 1991 rule, public water systems serving more than 50,000 people were required to survey their own corrosion control systems and to replace their pipelines with state-approved corrosion control by January 1, 1997. Suppliers who served a smaller number of people only had to replace their pipelines if action levels were exceeded at the tap.
EPA published the Lead and Copper Rule Minor Revisions (LCRMR) in January 2000. This rule required water suppliers to install the best available corrosion control mechanisms and to continually observe water levels, even if corrosion control was implemented. The revisions were effective April 11, 2000.
Additional corrections and minor revisions were made in 2004 and 2006.
Key features of the rule
- Contaminant from customer piping rather than source water or water company piping
- Action Level
- 90th percentilePercentileIn statistics, a percentile is the value of a variable below which a certain percent of observations fall. For example, the 20th percentile is the value below which 20 percent of the observations may be found...
- Not a Maximum Contaminant LevelMaximum Contaminant LevelMaximum Contaminant Levels are standards that are set by the United States Environmental Protection Agency for drinking water quality. An MCL is the legal threshold limit on the amount of a substance that is allowed in public water systems under the Safe Drinking Water Act...
(MCL) - Numerous Steps
- 90th percentile
- Sampling
- Customer Tap
- First Draw after 6 hours contact time
- Targeted locations
- Detailed educational requirement
- Service line replacement.
The action level for lead is 0.015 mg/L. The action level for copper is 1.3 mg/L. Water suppliers must monitor locations as specified in the rule. If the 90th percentile
Percentile
In statistics, a percentile is the value of a variable below which a certain percent of observations fall. For example, the 20th percentile is the value below which 20 percent of the observations may be found...
value of all the samples exceeds the action level, action must be taken. Actions may include investigation, recommendation of treatment, installation of treatment, checking of source water, removal of lead containing plumbing, and public education.
Since most of the lead found in drinking water leaches from the customer's pipes, fittings, and solder rather than from the source water, special sampling is necessary. Although the chemistry is complicated, the lead dissolved in the water generally increases with the amount of time the water has been in contact with the pipe. "First draw" samples must be water which has stood motionless for at least six hours.
The site selection process prioritizes sites by the likelihood of finding high lead concentrations which could impact people. Building codes and building records may be used to estimate the types of plumbing and solders at various buildings. Residential buildings are preferred over commercial. Only taps from which water is consumed are tested. The age of plumbing is taken into account, as older piping may reach an equilibrium with the water.
Unusual features of the rule
Because the source of lead and copper is generally the customer-owned piping (bronze and brass faucets, copper pipe, solder) rather than any part of the water supplier's plumbing, equipment, or even the original source of water, the lead and copper rule is quite unlike any of the other provisions of the National Primary Drinking Water Regulations. To some extent, the water supplier is made responsible for the quality of water sampled at pipes and locations completely out of the supplier's control. The most unusual features of the rule follow from this difference.While MCLs are risk-based, and the code requires the water supply take various actions based on the MCL, the lead and copper rule regulates the level of contamination at the customers' taps based on "action levels." No MCL is set for lead or copper. This method allows some percentage of the customer taps to exceed the "action level" without the water system having to take action. Especially for the larger systems, having the water supplier change the tendency of the water to dissolve lead in the customer plumbing may be more cost effective than having thousands of customers replace plumbing.
Also, because the source of lead and copper is the customer plumbing, lead and copper sampling is specified to be "first draw."
Most other water samples are taken by the water supplier's personnel. Trained personnel using consistent procedures generally yield more reliable data. The first draw sampling procedures make water supplier sampling impractical. Rather than have a technician spend six hours in a customer's home, the water supplier may leave the sample bottles and sampling instructions with the consumer.
Criticism
EPA was investigated by the Government Accountability OfficeGovernment Accountability Office
The Government Accountability Office is the audit, evaluation, and investigative arm of the United States Congress. It is located in the legislative branch of the United States government.-History:...
(GAO) in 2003 following the discovery of higher-than-acceptable copper and lead levels in tap water in the District of Columbia. The GAO reported that EPA had not been collecting copper and lead levels from the states, despite claims that the levels of copper and lead have decreased; data for 72 percent of water systems were missing. EPA may have been lacking data because more resources were being dedicated to lead regulation than lead reporting.