Regulation Timeline: Contaminants Regulated Under the Safe Drinking Water Act Federal Register Publication Month/Year Number of Contaminants (Cumulative) Action NPDWRs 22 (22) New regs 11/79 Total Trihalomethanes Rule 1 (23) New reg 2,4-D 2,4,5-TP (Silvex) arsenic barium cadmium chromium coliform bacteria endrin fluoride gross alpha gross beta lead total trihalomethanes (TTHMs2) 4/86 Fluoride Rule Revision fluoride* 7/87 Phase I (Volatile Organic Compounds) 1 (23) 8 (31) New regs benzene carbon tetrachloride 1,2-dichloroethane p-dichlorobenzene 1,1-dichloroethylene 6/89 Total Coliform Rule 1 (31) Revision total coliforms2 6/89 Surface Water Treatment Rule 5 (35) 1 Revision 4 New regs Giardia4 turbidity8 HPC bacteria4 Legionella4 viruses4 38 and 1 deletion (61) 11 Revisions 27 New regs 1 Deletion 2,4-D 2,4,5-TP acrylamide4 alachlor aldicarb aldicarb sulfone5 aldicarb sulfoxide5 asbestos atrazine barium cadmium carbofuran chlordane (mono) chlorobenzene chromium dibromochloropropane o-dichlorobenzene cis-1,2-dichloroethylene trans-1,2-dichloroethylene 1,2-dichloropropane epichlorohydrin4 copper4 ethylbenzene ethylene dibromide heptachlor heptachlor epoxide lindane mercury (inorganic) methoxychlor nitrate nitrite total nitrate/nitrite PCBs pentachlorophenol selenium silver9 styrene tetrachloroethylene toluene toxaphene xylenes adipate, di(2-ethylhexyl) antimony beryllium cyanide dalapon dichloromethane6 dinoseb dioxin (2,3,7,8-TCDD) diquat endothall endrin glyphosate nickel hexachlorobenzene hexachlorocyclopentadiene nickel oxamyl (vydate) PAHs (benzo(a) pyrene) phthalate, di(2-ethylhexyl) picloram simazine thallium 1,2,4-trichlorobenzene 1,1,2-trichloroethane 12/75; 7/76 1/91; 7/91 Final Regulation Phase II Contaminants Regulated 5 6/91 Lead and Copper 7/92 Phase V n/a/95 N/A 2 (62) 23 (84) 1 Revision 1 New reg 1 Revision 22 New regs 1 (83) Remand lindane mercury methoxychlor nitrate radium-2261 radium-2281 selenium silver toxaphene turbidity8 1,1,1-trichloroethane trichloroethylene vinyl chloride3 lead 4 Federal Register Publication Month/Year Final Regulation Number of Contaminants (Cumulative) Action 12/98 Stage I Disinfectant and Disinfection Byproduct Rule 7 (89) 1 Revision 6 New regs bromate chloramine chlorine chlorine dioxide chlorite haloacetic acids (HAA5)2 TTHMs2 12/98 Interim Enhanced Surface Water Treatment Rule 3 (90) 2 Revisions 1 New reg Cryptosporidium4 Giardia4 turbidity8 12/00 Radionuclides 5 (91) 4 Revisions 1 New reg radium-2281 uranium 01/00 Revision to the Lead and Copper Rule 2 (91) 2 Revisions gross alpha gross beta radium-2261 lead4 1/01 Arsenic Revision arsenic 6/01 Filter Backwash Recycling Rule 1 (91) 1 (91) Revision Cryptosporidium4 1/02 Long Term 1 Enhanced Surface Water Treatment Rule 2 (91) Revision Cryptosporidium4 1/06 Long Term 2 Enhanced Surface Water Treatment Rule 1 (91) Revision Cryptosporidium4 1/06 Stage 2 Disinfectant and Disinfection Byproduct Rule Ground Water Rule 2 (91) 2 Revisions HAA52 TTHMs2 3 (94) 3 New regs E. coli7 Enterococci7 coliphage7 10/07 Lead and Copper Rule 2 (94) 2 Revisions lead4 copper4 10/09 Airline Drinking Water Rule 1 (94) 10 New total coliforms2 2/13 Revised Total Coliform Rule 1 (94) 2 Revisions total coliforms2 11/06 Contaminants Regulated copper4 turbidity4,8 E. coli7 *Italics in the Contaminants Regulated column indicates a rule that was revised. Notes: 1. Radium-226 and radium-228 are counted as two contaminants although their standard is combined. 2. Total THMs, haloacetic acids, and total coliforms are counted as a single contaminant in the above table. However, each of these represent a group standard. The group standards consist of: TTHMs (chloroform, bromodichloromethane, dibromochloromethane, bromoform); TC (total coliform bacteria including fecal coliforms and E. coli); HAA5 (monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, bromoacetic acid, and dibromoacetic acid). 3. Vinyl chloride is also known as chloroethylene & monochloroethylene. 4. These nine contaminants have a treatment technique instead of a MCL. 5. Aldicarb, aldicarb sulfone, and aldicarb sulfoxide are considered regulated contaminants although their MCLs are stayed. 6. Dichloromethane is also known as methylene chloride. 7. E. coli, Enterococci, and coliphage are indicators of microbial contamination. 8. Turbidity is a measure of cloudiness in water that indicates the presence of disease-causing microbes. Higher turbidity levels are often associated with higher levels of disease-causing microorganisms such as viruses, parasites and some bacteria. 9. Silver was deleted during the Phase II regulatory action. 10. A new rule was developed applying specifically to airlines, but doesn’t change the total count of contaminants regulated since total coliforms were already regulated by another rule for non-airline drinking water systems. Updated September 2015