11905 PROPOSED RULES responding concentration _ shall not be cxeeeded: Temprrat vito din Fe) of (c°) fluoride Level (mp/t) we ‘Ye SOOO RT eee NUS fo SLO 9 10 TOT (0 TIS 10 ral ‘Sc of if ice $8.9, ASL, TH... 70.2 00 5 di) The maximum contaminant level for the total concentration of organic chem-: icals, as determined by the carbon chlo- roform extract method § 141.24¢b), Is 0.7 mg/l. set forth nents. : the fn membrane filter technique. The examined per month; or (B) Three or more portions {mn more ; Samples shall be taken at points which j arc representative of the conditions than five percent of the sampics if 20 or} § 141.13 Maximum contaminant levels” moro samples are examined per month. | within the distribution system. ‘for pesticides. ’ (b) The supplier of water shall take (ii) When the supplier of water emThe following are the maximum conploys the fermentation tube method and ; coliform density samples at regular intaminant levels for pesticides: 100 milliliter standard portions pursu- tervals throughout the month, and in (a) Chlorinated Hydrocarbons: ‘ ant to § 141.21(a) coliforms shall not be: number proportionate to the population Level mg/l present in more than 60 percent of the} served by the public water system. In no in any month; and either event shall the frequency be less than as Chlordane (cis and trans) (1,2.4.5,: portions (A) Five or more portions in more 6,7,8,8 “- Octachloro - 3n,4,5,7a: set forth below: tetrahydro-4,7-methanoindan) - 0.003 - than one sample when less than five! Minimum number of Endrin (1,2,3,4,10,10 - Hexachloro; samples . are cxamined; or. . Population served: Samples per month (B) Five or more portions in more 25 to 2.500 2 6,7 - epoxy - 1,4,49,5,6.7,8,8a- the ion ny ori- the Adion ny slic octahydro-1,4-endo, endo-5,8- , iter ply ate, aDp- and any but blic ions son; 2as- \ five samples or more are examined. i (b) The supplier of water shall pro-{ 4 ft vide water in which there shall be no 5} greater than 500 organisms per one mil- Heptachlor (1,4,5,6,7,.8,8-He p tachloro-30,4,7,7a-tetrahydro 4,7methnnoindene) ..----.----. 2. Heptochlor Epoxtde (1.4,5,6,7,8,8Heptachloro - 2,3-cpoxy-3n.4,7,7a~ tetrahydro-4,7-methanoindan) . Lindane (1,2,3,4,5,6-Hexachlorocyclohexane, gamma tsomer) -.-Methoxychior (1,1,1-Trichloro-2,2bis (p-methoxyphenyl| cthane)_ 0.1 Toxaphene (O,,#£,,01,—Technical chlorinated campheno, 67-69% ehiorine) .---.-.-----..------- 0.005 (b) Chlorophenoxys: © 2.4-D (2,4-Dichlordphenoxyacetic : acid) .. 2-21 oe ee eee 0.1 2,4,5-TP Silvex (2,4,5-Trichlorophenoxyproplonic acid) ~--...... 0.01 -yels § 141.14 Maximum of turbidity. jum em- The maximum contaminant level of turbidity in the drinking water at a representative entry point(s) to the distribution system is one turbidity unit (TU), as determined pursuant to § 141.22, except that five or fewer turbidity units evel too ya ~ o Nn a ne _o °o a g/l) > the sys- cor- contaminant level may be allowed If the supplier of water can demonstrate to the State that the higher turbidity does not: . (3) Interfere with disinfection; (b) Prevent maintenance of an effective disinfectant agent throughout the distribution system; and (c) Interfere with microbiological determinations. : § 141.15 Maximum microbiological contaminant levels. .(a) The supplier of water may employ one of two methods to determine compliance with the coliform maximum contaminant levels. ys rorzgte , than 20 percent of the samples when Il dimethnano naphthalene) -_.__-. wwronwwwr en: gea°¢ge 100 milliliters in more }t (a) The supplier of water shall mace coliform density measurements, for tne (2) (1) When the suppier of water em- | purpose of determining compliance with § 141.15, in accordance with the anatytiploys the fermentation tubo method ana cal recommendations set forth in 10 milliliter standard portions pursuant : “Standard Methods for the Examination to § 141.21, coliforms shall not be present in more than 10 percent of the por- , of Water and Wastewater.” American’ ! Public Health Association, 13th Edition, tions in any month; and cither (A) Three or more portions in one i pp 662-688, except that only a 100 millisample when less than 20 samples are;; liter sample size shall be employed in § 141.22 Maximunt contaminant levels: for organic chemicals. : on tor in (2) ige ich ith Four per than five percent of the standard samples when 20 or more are examined per month. serving only educational tnstitulions. als ne {§ 142.21. When the supplier of water ex- the membrane filter technique ,ercises the option provided by this para\ purstant to § 141.21(a) the coliform {graph (b) he shall maintain no less than + 0.3 mg/l free chlorine in the public water \ densities shall not exeeed c one per 100 distribution system, Menasuremenis saau milliliters as the arithmeti mean of all i samples examined per month; andeither be made in accordance with “Standard () Four per 100 milliliters In more ; Methods," 13th td., pp 129-132. tI : than one standard sample when less '§ 3412) Microbiologie! contaminant > than 20 are examined per month: or t sampling and analytical require- The requirements of this pararraph (b) ido hot apply to public water supplies» ore When the supplicr of water em- (1) t I ploys i : iter as determined by the standard ! bacterial plate count provided in 3 141.21(f). § 141.16 Substitution of residual chlo. rine measurement for total coliform 2.501 to 3,300......-.... 0 3 4,101 to 4,900___.-__.___ 4,901 to 5,800___.-.-_-----...2-.2-.-5,801 to 6,700._---.- 2... 5 € 7 3.301 to 4.100...------- Reeenennes 6,701 to 7,600. _.-----.--------a eot ° Bao0noneee 8,401 to 10,300_.._-10,301 to 4 8 i 1 12 to bol ee 13 (a) The supplier of water may, with 13,701 to 16 use of chlorine residual ménitoring for 15.501 to required to be taken by § 141.21 (b), pro- 18.101 to micasurement. 4 ‘the approval of the State, substitute the not more than 75 percent of the samples vided that the supplier chlorine residual samples are representative of within the distribution of water takes at points which the conditions system at the frequency of at least four for cach sub- stituted microbiological sample. There shall be at least daily determinations of chlorine residual. Measurements shall be made in accordance with “Standard Methods,” 13th Ed., pp 129-132. When 12.901 to 14,601 to }6:007 [© 18.901 19,801 20,701 21,501 to to to to 22,301 to 18 3 21 22 23 24 25 26 27 an 33,001 to 37,000 40 25,001 to 28.000 28,001 to 33.000 37.001 to 41,000 41,001 to 46,000 46,001 to 50,000 4900 or fewer persons, the supplier may, _.__.. 70,001 to 76.000 _...... with the approval of the State, make a total substitution of chlorine residual measurement for the samples required to 17 oar a 2 oa oot te 95'000 the supplier af water exercises the option provided in this paragraph (1), he shall maintain no less than 0.2 mg/1 free chlorine in the public water distribution sysrem. . . ) For public water systems serving 13 89.001 10 54.000 59,001 to 64,000 64.001 to 70,000 76,001 to 83,000 83,001 to 90,000 90,001 to 96,000 30 35 45 50 55 so 70 15 20 85 90 95 be taken by § 141.21(b): Provided, That pooor to 1008wnnnnn ee sentative of the conditions within the distribution system at the rate of one igg‘o901 to 220:000_................ ne 929.001 to 280000... -* 350 the supplier of water takes chlorine residual samples at points which are repre- per day for each microbiological sample required to be ‘taken. per month-under . 0 T8000 — = tee'pot * ioe pone -- 109 -ceceen u 250,001 to 290,000... --- 169 290,001 to 320,000__...-..--_-..---- n- 170 FEDERAL REGISTER, VOL. 40, NO. 51—FRIDAY, MARCH 14, 1975 18410