12VAC5-590-340: Compliance standards

A. All physical, chemical, bacteriological, or radiological analyses for the purpose of demonstrating compliance with the requirements of this chapter shall be performed by laboratories that have received certification by EPA or DCLS as specified in 12VAC5-590-440. The owner is responsible for the collection and submission of all samples. The department may require sampling and testing that exceeds the minimal requirements specified in this chapter. A sample is deemed to have been collected only when its results are made known to the department.

B. Specific limits. No attempt has been made to prescribe specific limits for every contaminant that might occur in a water supply or a waterworks. Although the need exists for continued attention to the entry of chemical, physical, bacteriological, and radiological substances into drinking water, the limits are confined to substances recognized as being detrimental to the health or well-being of the consumer or that cause significant degradation of the usefulness of the water. Limits for innumerable substances would require an impossible burden of analytical examination. The specific limits included in this chapter are listed in Tables 340.1 through 340.7.

C. Compliance is determined:

1. Based on sample results or calculated averages, where appropriate, rounded to the same number of significant figures as the PMCL, SMCL, AL, or MRDL of the contaminant in question, or

2. By the application of the specific treatment technique for particular contaminants (see 12VAC5-590-391).

TABLE 340.1

Inorganic Chemicals

SUBSTANCE

PMCL (mg/L)

Antimony

0.006

Arsenic

0.010a

Asbestos

7 million fibers/liter (longer than 10 µm)

Barium

2

Beryllium

0.004

Cadmium

0.005

Chromium

0.1

Cyanide (as free Cyanide)

0.2

Fluoride

4.0b

Mercury

0.002

Nickel

No limits designated

Nitrate (as N)

10c

Nitrite (as N)

1.0c

Total Nitrate and Nitrite (as N)

10c

Selenium

0.05

Thallium

0.002

SUBSTANCE

SECONDARY MAXIMUM CONTAMINANT LEVEL (mg/L)

Aluminum

0.05-0.2d

Chloride

250c

Copper

1.0

Corrosivity

Noncorrosive

Fluoride

2.0

Foaming agents

0.5e

Iron

0.3

Manganese

0.05

Silver

0.1

Sodium

No limits designatedf

Sulfate

250c

Zinc

5

SUBSTANCE

ACTION LEVEL (mg/L)

Lead

0.015

Copper

1.3

aArsenic sampling results shall be reported to the nearest 0.001 mg/L.

bThe fluoride PMCL applies only to community waterworks.

cSignificant figures are noted as shown. For values with trailing zeros, significant figures are noted as shown. The limits for nitrate and nitrate-nitrite have two significant figures. The limits for chloride and sulfate have three significant figures.

dVarying water quality and treatment situations necessitates a flexible range for the aluminum SMCL. The owner is encouraged to maintain an aluminum concentration as low as possible. If the aluminum concentration in the finished water causes discoloration, then the owner is urged to contact the department.

eConcentrations reported in terms of Methylene Blue Active Substances.

fMonitoring and reporting in accordance with 40 CFR 141. 41 and 12VAC5-590-372 D 6.

TABLE 340.2

Organic Chemicals

SUBSTANCE

PMCL (mg/L)

VOC

Benzene

0.005

Carbon tetrachloride

0.005

Chlorobenzene (also called Monochlorobenzene)

0.1

o-Dichlorobenzene

0.6

p-Dichlorobenzene

0.075

1,2-Dichloroethane (also called Ethylene dichloride)

0.005

1,1-Dichloroethylene (also called Dichloroethene)

0.007

cis-1,2-Dichloroethylene

0.07

Trans-1,2-Dichloroethylene

0.1

Dichloromethane (also called Methylene chloride)

0.005

1,2-Dichloropropane

0.005

Ethylbenzene

0.7

Styrene

0.1

Tetrachloroethylene (PCE) (also called Perchloroethylene)

0.005

Toluene

1

1,2,4-Trichlorobenzene

0.07

1,1,1-Trichloroethane

0.2

1,1,2-Trichloroethane

0.005

Trichloroethylene (TCE)

0.005

Vinyl Chloride

0.002

Xylene (total)

10a

SOC

Acrylamide

TTb

Alachlor (also called Lasso)

0.002

Atrazine

0.003

Benzo(a)pyrene

0.0002

Carbofuran

0.04

Chlordane

0.002

Dalapon

0.2

Di(2-ethylhexyl)adipate (also called Bis(2-ethylhexyl)adipate)

0.4

Di(2-ethylhexyl)phthalate (also called Bis(2-ethylhexyl)phthalate)

0.006

1,2-Dibromo-3-chloropropane (DBCP)

0.0002

2,4-Dichlorophenoxyacetic Acid (2,4-D)

0.07

Dinoseb

0.007

Diquat

0.02

Endothall

0.1

Endrin

0.002

Epichlorohydrin

TTb

Ethylene dibromide (EDB) (also called 1,2-Dibromoethane)

0.00005

Glyphosate

0.7

Heptachlor

0.0004

Heptachlor epoxide

0.0002

Hexachlorobenzene

0.001

Hexachlorocyclopentadiene

0.05

Lindane (also called gamma-HCH and gamma BHC)

0.0002

Methoxychlor

0.04

Oxamyl (Vydate)

0.2

Pentachlorophenol (PCP)

0.001

Picloram

0.5

Polychlorinated biphenyls (PCBs)

0.0005

Simazine

0.004

2,3,7,8-TCDD (Dioxin)

3 X 10-8

Toxaphene

0.003

2,4,5-Trichlorophenoxypropionic Acid (2,4,5-TP or Silvex)

0.05

aThe limit for xylene has two significant figures.

bEach waterworks must certify annually to the department that when acrylamide and epichlorohydrin are used to treat water, the combination (or product) of dose and monomer level does not exceed the levels specified as follows: (i) acrylamide = 0.05% dosed at 1 mg/L (or equivalent) and (ii) epichlorohydrin = 0.01% dosed at 20 mg/L (or equivalent). The certification shall be in writing, using third-party certification approved by the department or the manufacturer's certification.

TABLE 340.3

Physical Quality

PARAMETER

STANDARD

CONCENTRATION

Color

SMCL

15 Color Units (CU)

Odor

SMCL

3 Threshold odor numbers

pH

SMCL

6.5-8.5

Total dissolved solids (TDS)

SMCL

500 mg/La

Turbidity

Treatment Technique

See 12VAC5-590-395 A 2 bb

aTDS has three significant figures.

bOperational goal: Surface water treatment plants with gravity flow granular media filters are capable of producing filtered water with a turbidity consistently less than 0.10 NTU. Therefore, for water treatment plants, the operational goal for filter effluent turbidity for each filter, before any post-filtration chemical addition, is 0.10 NTU.

TABLE 340.4

Radiological Quality

PARAMETER

PMCL

Combined radium-226 and radium-228.

5 pCi/L

Gross alpha particle activity (excluding Radon and Uranium)

15 pCi/L

Beta particle and photon radioactivity.

4 mrem/yr a, b

Uranium

30 µg/Lc

aThe average annual concentration of beta particle and photon radioactivity from man-made radionuclides in drinking water shall not produce an annual dose equivalent to the total body or any internal organ greater than 4 mrem/year.

bExcept for the radionuclides listed in Schedule I, the concentration of man-made radionuclides causing 4 mrem total body or organ dose equivalents shall be calculated on the basis of a 2 liter per day drinking water intake using the 168-hour data listed in "Maximum Permissible Body Burdens and Maximum Permissible Concentrations of Radionuclides in Air and in Water for Occupational Exposure," NBS Handbook 69 issued June 5, 1959, and amended August 1963, U.S. Department of Commerce. If two or more radionuclides are present, the sum of their annual dose equivalent to the total body or to any organ shall not exceed 4 mrem/year.

cThe limit for uranium has two significant figures.

Schedule 1

Average annual concentrations assumed to produce a total body organ dose of 4 mrem/year.

RADIONUCLIDE

CRITICAL ORGAN

pCi/L

Tritium

Total Body

20,000d

Strontium-90

Bone Marrow

8

dThe limit for tritium has five significant figures.

TABLE 340.5

Microbial Contaminants

CONTAMINANT

PMCL or TT

Cryptosporidium

TT

Minimum 99% (2-log) removal plus additional log removal or inactivation based upon bin classification in 12VAC5-590-401 D.

Giardia lamblia

TT

99.9% (3-log) removal or inactivation.

Viruses

TT

99.99% (4-log) removal or inactivation

Legionella

TT

No limit, but if Giardia lamblia and viruses are removed or inactivated, according to the treatment techniques in 12VAC5-590-395, Legionella will also be controlled.

Heterotrophic plate count (HPC)

TT

No more than 500 bacterial colonies per milliliter. (HPC is not a contaminant, it is an analytic method used to measure a variety of bacteria found in water.)

Escherichia coli (E. coli)

PMCL

(1) Any E. coli-positive repeat sample following a total coliform-positive routine sample.

(2) Total coliform-positive repeat sample following an E. coli-positive routine sample.

(3) Failure to collect all require repeat samples following an E. coli-positive routine sample.

(4) Failure to test for E. coli when any repeat sample tests positive for total coliform.

TABLE 340.6

Disinfection Byproducts

PARAMETER

PMCL (mg/L)

TTHM

Bromodichloromethane

Bromoform

Chloroform

Dibromochloromethane

0.080a

HAA5

Bromoacetic acid

Dibromoacetic acid

Dichloroacetic acid

Monochloroacetic acid

Trichloroacetic acid

0.060a

Bromate

0.010a

Chlorite

1.0a

aThe limits for TTHM, HAA5, and bromate have three significant figures. The limit for chlorite has two significant figures.

TABLE 340.7

Maximum Residual Disinfectant Level Goals (MRDLG) and Maximum Residual Disinfectant Levels (MRDL) for Disinfectants

RESIDUAL DISINFECTANT

MRDLG and MRDL (mg/L)

Chlorine

4.0 (as Cl2)a

Chloramines

4.0 (as Cl2)a

Chlorine Dioxide

0.8 (as ClO2)

aChlorine and chloramines have two significant figures.

D. Notwithstanding the MRDLs in Table 340.7, an owner may increase the residual disinfectant level of chlorine or chloramines (but not chlorine dioxide) in the distribution system to a level and for a time necessary to protect public health. This may include specific microbiological contamination problems caused by circumstances such as distribution line breaks, storm runoff events, water supply contamination events, or cross-connection events.