What are drinking water standards?
The Federal Environmental Protection Agency (EPA) limits the amount of certain substances allowed in tap water. In California, the Department of Health Services regulates tap water quality by enforcing limits that are at least as stringent as the Federal EPA’s. Historically, California limits are more stringent than the Federal ones. There are two types of these limits, known as standards. Primary standards protect you from substances that could potentially affect your health. Secondary standards regulate substances that affect the aesthetic qualities of water. Regulations set a Maximum Contaminant Level (MCL) for each of the primary and secondary standards. The MCL is the highest level of a substance that is allowed in your drinking water. Public Health Goals (PHGs) are set by the California Environmental Protection Agency.
The Safe Drinking Water Act (SDWA) was signed into law on December 16, 1974. The purpose of the law is to assure that the nation’s water supply systems serving the public met minimum national standards for the protection of public health. The SDWA covers all public water systems with piped water for human consumption with at least 15 service connections or a system that regularly serves at least 25 individuals. The SDWA directed the U.S. Environmental Protection Agency (EPA) to establish national drinking water standards. hese standards limit the amount of certain contaminants provided by public water. Food and Drug Administration (FDA) regulations establish limits for contaminants in bottled water. All drinking water, including bottled water, may reasonably be expected to contain at lesat small amounts of some contaminants. The presence of contaminants does not necessarily indicate that the water poses a health risk.
Sr. No. Impurity Non Packaged Packaged IS desirable limit (As per IS 10500) USEPA Maximum contaminant level WHO guideline value IS desirable limit (As per IS 14543:2004) 1 Colour, Hazen units 5 NA 15 true colour units 2 2 Odour Agreeable 3 threshold odour number Not offensive Agreeable 3 Taste Agreeable NA Not offensive Agreeable 4 Turbidity, NTU 5 5 5 2 5 Dissolved solids, mg/l 500 500 1000 500 6 Total hardness, mg/l (as CaCO3) 300 NA 500 NA 7 Ca, mg/l 75 — — 75 8 Mg, mg/l — — — 30 9 PH value 6.5 8.5 6.5 8.5 6.5 8.5 6.5 8.5 10 Manganese, mg/l 0.1 0.05 0.1 0.1 11 Chlorides, mg/l 250 250 250 200 12 Sulphates, mg/l 200 250 400 200 13 Nitrates, mg/l 45 10 10 45 14 Fluorides, mg/l 1.0 2.0 1.5 1.0 15 Phenolic compounds, mg/l 0.001 0.001 0.001 0.001 16 Mercury, mg/l 0.001 0.002 0.001 0.001 17 Cadmium, mg/l 0.01 0.005 0.003 0.01 18 Selenium, mg/l 0.01 0.05 0.01 0.01 19 Arsenic, mg/l 0.04 0.01 0.01 0.05 20 Cyanide, mg/l 0.05 0.2 0.1 Absent 21 Lead, mg/l 0.05 0.015 0.01 0.01 22 Zinc, mg/l
Drinking water standards are the standards given by EPA for the allowable levels of contaminants in our drinking water, which may not cause any health hazard. EPA has set two categories for regulating drinking water standards, National Primary Drinking Water Regulation (NPDWR) and National Secondary Drinking Water Regulation (NSDWR). NPDWR apply to public water system and regulate contaminants that may be harmful to human health when ingested. NSDWR is set to regulate contaminant that may have harmful cosmetic affects like discoloration of teeth, skin and nails. It also regulates the standards of aesthetic qualities like, taste, color, and odor. More information on these regulation can be found on EPA’s Groundwater and Drinking Water page.
Drinking water standards give the acceptable level of a pollutant in drinking water. There are two types of standards: primary and secondary. Primary standards apply to pollutants that cause health problems, such as coliform bacteria, nitrate, or lead. Secondary pollutants apply to pollutants that cause aesthetic problems (stains, odors, tastes) such as iron, manganese, or chloride. There are more than 100 pollutants with a drinking water standard.
