New Mexico Administrative Code › Title 20 - ENVIRONMENTAL PROTECTION › Chapter 6 - WATER QUALITY › Part 4 - STANDARDS FOR INTERSTATE AND INTRASTATE SURFACE WATERS › Section 20.6.4.7 - DEFINITIONS

Current through Register Vol. 35, No. 13, July 16, 2024
Terms defined in the New Mexico Water Quality Act, but not
				  defined in this part will have the meaning given in the Water Quality
				  Act.
A.
Terms beginning with
				numerals or the letter "A," and abbreviations for units.
(1)
"4Q3"
means the critical low
				flow as determined by the minimum average flow over four consecutive days that
				occurs with a frequency of once in three years.
(2)
"4T3 temperature"
means the
				temperature not to be exceeded for four or more consecutive hours in a 24-hour
				period on more than three consecutive days.
(3)
"6T3 temperature"
means the
				temperature not to be exceeded for six or more consecutive hours in a 24-hour
				period on more than three consecutive days.
(4)
Abbreviations
used to
				indicate units are defined as follows:
(a)
"cfu/100 mL"
means colony-forming units per 100 milliliters; the
				results for
E. coli
may be reported as either colony forming
				units (CFU) or the most probable number (MPN), depending on the analytical
				method used;
(b)
"cfs"
means cubic feet per second;
(c)
"µg/L"
means micrograms per liter, equivalent to parts per
				billion when the specific gravity of the solution equals 1.0;
(d)
"µS/cm"
means
				microsiemens per centimeter; one µS/cm is equal to one
				µmho/cm;
(e)
"mg/kg"
means milligrams per kilogram, equivalent to parts per
				million;
(f)
"mg/L"
means milligrams per liter, equivalent to parts per million when the specific
				gravity of the solution equals 1.0;
(g)
"MPN/100 mL"
means most
				probable number per 100 milliliters; the results for
E. coli
may be reported as either CFU or MPN, depending on the analytical method
				used;
(h)
"NTU"
means
				nephelometric turbidity unit;
(i)
"pCi/L"
means picocuries per liter;
(j)
"pH"
means the measure of
				the acidity or alkalinity and is expressed in standard units (su).
(5)
"Acute toxicity"
means toxicity involving a stimulus severe enough to induce a response in 96
				hours of exposure or less. Acute toxicity is not always measured in terms of
				lethality, but may include other toxic effects that occur within a short time
				period.
(6)
"Adjusted gross
				alpha"
means the total radioactivity due to alpha particle emission as
				inferred from measurements on a dry sample, including radium-226, but excluding
				radon-222 and uranium. Also excluded are source, special nuclear and by-product
				material as defined by the Atomic Energy Act of 1954.
(7)
"Aquatic life"
means any
				plant or animal life that uses surface water as primary habitat for at least a
				portion of its life cycle, but does not include avian or mammalian
				species.
(8)
"Attainable
				Use"
means a use that is achievable by the imposition of effluent limits
				required under sections 301(b) and 306 of the federal Clean Water Act and
				implementation of cost-effective and reasonable best management practices for
				nonpoint source control. An attainable use may or may not have criteria as
				stringent as the criteria for the designated use.