FACTS ABOUT LEAD IN WATER
| Contaminant | In Water As | Maximum Contaminant Level |
| Lead (Pb) | Pb(OH)2, PbCO3 and Pb2O | US EPA: Action Level* = 0.015 mg/L MCLG** = 0.00 mg/L (or ppm) WHO† Guideline = 0.01 mg/L |
*Action Level requires water utilities to sample specific number of samples in specific locations and verify that 90% of samples are below this level. If that is not met, an appropriate Action is required to be taken to remedy the situation.
**Maximum Contaminant Level Goal (MCLG) – The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety and are non-enforceable public health goals.
+WHO -World Health Organization
| Sources of Contaminant | Mostly lead service lines, lead containing solder, and brass fittings of different types Industrial processes, mines, and smelting (not a direct source into water) |
| Potential Health Effects | Children are more at risk than adults Reduced intelligence, impaired hearing and decreased growth in children Damage to the brain, kidneys, and bone marrow Damage nervous system and red blood cells |
| Treatment Methods Point-of-Entry Point-of-Use | Reverse Osmosis Solid Block and Precoat Adsorption Filters (properly designed submicron filtration with adsorption media) Strong Acid Cation Exchange (Na+ form) Distillation |
NOTE: Lead can exist in water in a broad array of forms, therefore, more than one type of technology may be needed for adequate removal. Soluble (or dissolved) lead may be removed by ion exchange, reverse osmosis, adsorption, or distillation. Insoluble (or particulate) lead may be removed by fine filtration and adsorption, reverse osmosis, or distillation.
Regulations
In the United States the EPA, under the authority of the Safe Drinking Water Act (SDWA), has set the Maximum Contaminant Level Goal (MCLG) for lead at zero. This is the health-based goal at which no known or anticipated adverse effects on human health occur and for which an adequate margin of safety exists. It means that it would be desirable to have totally lead free water for consumption. But due to economic considerations USEPA has set an action level for lead in drinking water at 15 ppb (15μg/L). This means that utilities must ensure that water from the customer’s tap does not exceed this level in at least 90 percent of the homes sampled. The utility must take certain steps to correct the problem if the tap water exceeds the limit and they must notify citizens of all violations of the standard. In Canada, the regulated concentration of lead is set at 0.010 mg/L.
Amendments to the SDWA require the use of “lead-free” pipe, solder, and flux in the installation or repair of any public water system, or any plumbing in a residential or non-residential facility connected to a public water system. Solders and flux are considered “lead-free” when they contain not more than 0.2 percent lead. Solders used prior to 1986 typically contained about 50 percent lead. Pipes and fittings were considered “lead-free” when they contained no more than 8 percent lead until the end of 2013. A report shows that lead in drinking water can increase by more than 100 fold after 24 hrs of contact with lead-soldered copper piping. Current regulation that took effect in January 2014 in the US now requires all plumbing systems to be lead free, i.e. contain less than 0.25 % lead.
Revisions to the Lead & Copper rule proposed in December 2021 would allow public water systems serving fewer than 10,000 customers to use POU treatment as a long-term compliance solution (USEPA, 2020). The compliance date for the new rule is October 16, 2024.
Several public water systems have used POU treatment as temporary measures to address lead problems while they make necessary lead-line replacements or adjust their central treatment (City of Detroit, 2023; City of Evanston, n.d.; City of Newark, 2019; City of Pittsburgh, n.d.; Denver Water, 2023; USEPA, 2016; USEPA, 2022) . Systems tend to use pitcher filters or faucet mounted filters for this purpose. POU reverse osmosis is also an effective treatment method, however, the pitcher and faucet mounted filters are more attractive due to their lower cost, and the ease of implementation.
Due to variances in water chemistry around the country, carbon block filters can have limitations, even when certified to NSF/ANSI Standard 53 for lead concentration reduction. In 2019, with assistance from the USEPA, the city of Newark, New Jersey found that the addition of zinc othophosphate to their low hardness and low carbonate water produced lead particulates that were smaller than those used in product certification testing (Lytle et al., 2020).. Although the testing performed by the city and the EPA eventually proved “that the filters distributed by the City are reliable in reducing lead levels in tap water to below USEPA’s action level of 15 ppb” (NJDEP, 2019) follow up testing on performance after installation is recommended when filters are used in this manner. The city also found that proper installation, maintenance, and certified replacement cartridges were critical in the filters’ performance (Kutzing et al, 2022).
This information is sourced from the Water Quality Association (WQA) of which WCC is a proud member. Complete reports are available via the links below. This material is shared with the objective of offering comprehensive, professional insights into relevant water quality standards and guidelines.