N.M. Admin. Code § 20.6.2.3103 - STANDARDS FOR GROUND WATER OF 10,000 mg/l TDS CONCENTRATION OR LESS

The following standards are the allowable pH range and the maximum allowable concentration in ground water for the contaminants specified unless the existing condition exceeds the standard or unless otherwise provided in Subsection E of Section 20.6.2.3109 NMAC. Regardless of whether there is one contaminant or more than one contaminant present in ground water, when an existing pH or concentration of any water contaminant exceeds the standard specified in Subsection A, B, or C of this section, the existing pH or concentration shall be the allowable limit, provided that the discharge at such concentrations will not result in concentrations at any place of withdrawal for present or reasonably foreseeable future use in excess of the standards of this section. These standards shall apply to the dissolved portion of the contaminants specified with a definition of dissolved being that given in the publication "methods for chemical analysis of water and waste of the U.S. environmental protection agency," with the exception that standards for mercury, organic compounds and non-aqueous phase liquids shall apply to the total nonfiltered concentrations of the contaminants. If the secretary determines that there is a reasonable probability of facilitated contaminant transport by colloids or organic macromolecules, or that proper filtration procedures are not being followed, the discharger may be required to test for both filtered and nonfiltered portions of inorganic contaminants to develop appropriate protocol for monitoring contaminants that have the potential to migrate through the aquifer.

A. Human Health Standards

(1) Numerical Standards

(a) Antimony (Sb) (CAS 7440-36-0)............0.006 mg/1

(b) Arsenic (As) (CAS 7440-38-2)............0.01 mg/l

(c) Barium (Ba) (CAS 7440-39-3)...............2 mg/l

(d) Beryllium (be) (CAS 7440-41-7)........0.004 mg/l

(e) Cadmium (Cd) (CAS 7440-43-9)...........0.005 mg/l

(f) Chromium (Cr) (CAS 7440-47-3)....... ....0.05 mg/l

(g) Cyanide (CN) (CAS 57-12-5)..............0.2 mg/l

(h) Fluoride (F) (CAS 16984-48-8)............1.6 mg/l

(i) Lead (Pb) (CAS 7439-92-1)..........0.015 mg/l

(j) Total Mercury (Hg) (CAS 7439-97-6)...........0.002 mg/l

(k) Nitrate (NO₃ as N) (CAS 14797-55-8)............10.0 mg/l

(l) Nitrite (NO₂ as N) (CAS 10102-44-0)...........1.0 mg/l

(m) Selenium (Se) (CAS 7782-49-2)............0.05 mg/l

(n) Silver (Ag) (CAS 7440-224)............0.05 mg/l

(o) Thallium (Tl) (CAS 7440-28-0).............0.002 mg/l

(p) Uranium (U) (CAS 7440-61-1)............0.03 mg/l

(q) Radioactivity: Combined Radium-226 (CAS 13982-63-3) and Radium-228 (CAS 15262-20-1)...........5 pCi/l

(r) Benzene (CAS 71-43-2).............0.005 mg/l

(s) Polychlorinated biphenyls (PCB's) (CAS 1336-36-3).0.0005 mg/l

(t) Toluene (CAS 108-88-3)..................1 mg/l

(u) Carbon Tetrachloride (CAS 56-23-5)...........0.005 mg/l

(v) 1,2-dichloroethane (EDC) (CAS 107-06-2).......0.005 mg/l

(w) 1,1-dichloroethylene (1,1-DCE) (CAS 75-35-4).....0.007 mg/l

(x) tetrachloroethylene (PCE) (CAS 127-18-4).....0.005 mg/l

(y) trichloroethylene (TCE) (CAS 79-01-6).........0.005 mg/l

(z) ethylbenzene (CAS 100-41-4).............0.7 mg/l

(aa) total xylenes (CAS 1330-20-7)........................0.62 mg/l

(bb) methylene chloride (CAS 75-09-2)............0.005 mg/l

(cc) chloroform (CAS 67-66-3).................0.1 mg/l

(dd) 1,1-dichloroethane (CAS 75-34-3)..............0.025 mg/l

(ee) ethylene dibromide (EDB) (CAS 106-93-4)......0.00005 mg/l

(ff) 1,1,1-trichloroethane (CAS 71-55-6)..............0.2 mg/l

(gg) 1,1,2-trichloroethane (CAS 79-00-5).............0.005 mg/l

(hh) 1,1,2,2-tetrachloroethane (CAS 79-34-5).............0.01 mg/l

(ii) vinyl chloride (CAS 75-01-4)..............0.002 mg/l

(jj) PAHs: total naphthalene (CAS 91-20-3) plus monomethylnaphthalenes .0.03 mg/l

(kk) benzo-a-pyrene (CAS 50-32-8)............0.0002 mg/l

(ll) cis-1,2-dichloroethene (CAS 156-59-2)............0.07 mg/l

(mm) trans-1,2-dichloroethene (CAS 156-60-5)............0.1 mg/l

(nn) 1,2-dichloropropane (PDC) (CAS 78-87-5)..........0.005 mg/l

(oo) styrene (CAS 100-42-5).....................0.1 mg/l

(pp) 1,2-dichlorobenzene (CAS 95-50-1)...............0.6 mg/l

(qq) 1,4-dichlorobenzene (CAS 106-46-7)..............0.075 mg/l

(rr) 1,2,4-trichlorobenzene (CAS 120-82-1).............0.07 mg/l

(ss) pentachlorophenol (CAS 87-86-5)...............0.001 mg/l

(tt) atrazine (CAS 1912-24-9).................0.003 mg/l

(2) Standards for Toxic Pollutants. A toxic pollutant shall not be present at a concentration shown by credible scientific data and other evidence appropriate under the Water Quality Act, currently available to the public, to have potential for causing one or more of the following effects upon exposure, ingestion, or assimilation either directly from the environment or indirectly by ingestion through food chains:

(1) unreasonably threatens to injure human health, or the health of animals or plants which are commonly hatched, bred, cultivated or protected for use by man for food or economic benefit; as used in this definition injuries to health include death, histopathologic change, clinical symptoms of disease, behavioral abnormalities, genetic mutation, physiological malfunctions or physical deformations in such organisms or their offspring; or

(2) creates a lifetime risk of more than one cancer per 100,000 exposed persons.

(3) Standards for Non-Aqueous Phase Liquids. Non-aqueous phase liquid shall not be present floating atop of or immersed within ground water, as can be reasonably measured.

B. Other Standards for Domestic Water Supply

(1) Chloride (Cl) (CAS 16887-00-6).....................250.0 mg/l

(2) Copper (Cu) (CAS 7440-50-8)......................1.0 mg/l

(3) Iron (Fe) (CAS 7439-89-6)......................1.0 mg/l

(4) Manganese (Mn) (CAS 7439-96-5)..................0.2 mg/l

(5) Phenols...........................0.005 mg/l

(6) Sulfate (SO₄) (CAS 14808-79-8)...................600.0 mg/l

(7) Total Dissolved Solids (TDS) TDS..................1000.0 mg/l

(8) Zinc (Zn) (CAS 7440-66-6)........................10.0 mg/l

(9) pH...........................between 6 and 9

(10) Methyl tertiary-butyl ether (MTBE) (CAS 1634-04-4)..........0.1 mg/l

C. Standards for Irrigation Use - Ground water shall meet the standards of Subsection A, B, and C of this section unless otherwise provided.

(1) Aluminum (Al) (CAS 7429-90-5)..................5.0 mg/l

(2) Boron (B) (CAS 7440-42-8).....................0.75 mg/l

(3) Cobalt (Co) (CAS 7440-48-4)...................0.05 mg/l

(4) Molybdenum (Mo) (CAS 7439-98-7)..................1.0 mg/l

(5) Nickel (Ni) (CAS 7440-02-0)......................0.2 mg/l

D. For purposes of application of the amended numeric standards for arsenic, cadmium, lead, combined radium-226 & radium-228; benzene, PCBs, carbon tetrachloride, EDC, PCE, TCE, ethylbenzene, methylene chloride, EDB, 1,1,2-trichloroethane and benzo-a-pyrene, to past and current water discharges (as of July 1, 2017), the new standards will not become effective until July 1, 2020. With regard to sites for which the secretary has approved an abatement completion report as of the effective date of this rule pursuant to 20.6.2.4112 NMAC, the amended numeric standards for arsenic, cadmium, lead, combined radium-226 & radium-228; benzene, PCBs, carbon tetrachloride, EDC, PCE, TCE, ethylbenzene, methylene chloride, EDB, 1,1,2-trichloroethane and benzo-a-pyrene shall not apply unless the secretary notifies the responsible person that the site is a source of these contaminants in ground water that pose a hazard to public health.

Notes

N.M. Admin. Code § 20.6.2.3103

2-18-77, 1-29-82, 11-17-83, 3-3-86, 12-1-95; 20.6.2.3103 NMAC - Rn, 20 NMAC 6.2.III.3103, 1-15-01; A, 9-26-04, Amended by New Mexico Register, Volume XXIX, Issue 23, December 11, 2018, eff. 12/21/2018

For purposes of application of the amended numeric uranium standard to past and current water discharges (as of 9-26-04), the new standard will not become effective until June 1, 2007. For any new water discharges, the uranium standard is effective 9-26-04.