12 Va. Admin. Code § 5-630-431

Current through Register Vol. 41, No. 8, December 2, 2024

Section 12VAC5-630-431 - Water quality

A. Class IV wells exempt. The water quality requirements contained in this section apply to Class III private wells. Class IV private wells (wells not constructed as a source of water for human consumption) are not subject to water quality requirements.

B. Sample tap. A sample tap shall be provided at or near the water entry point into the system so that samples may be taken directly from the source; this requirement may be met by utilizing the first tap on a line near where the plumbing enters the house (may be a hose bib), provided the tap precedes any water treatment devices.

C. Disinfection. The entire water system, including the well, shall be disinfected prior to use pursuant to 12VAC5-630-430.

D. Sampling. After operating the well to remove any remaining disinfectant, a sample of the water from the well shall be collected for bacteriological examination. The sample may be collected by the owner, water well systems provider, or other person in accordance with procedures established by the department and provided the sample is submitted to a private laboratory accredited by the Department of General Services, Division of Consolidated Laboratory Services, for analysis.

E. Test interpretation. A Class III private well shall be considered satisfactory if the water sample tests negative for coliform organisms as described in subdivision 1 or 2 of this subsection. Sources with positive counts shall be tested as described in subdivision 3 of this subsection to determine if the water supply is amenable to continuous disinfection. Samples that exhibit confluent growth shall be considered inconclusive and another sample shall be collected.

1. When a private well has no unsatisfactory water sample within the previous 12 months, one water sample which tests negative for coliform bacteria shall be considered satisfactory for coliform organisms.

2. When a private well has had one or more positive water samples within the past 12 months for coliform bacteria, at least two consecutive samples must be collected and found negative for coliform organisms before the supply may be considered satisfactory for coliform organisms. The samples must be collected at least 24 hours apart and the well may not be disinfected between samples.

3. When a private well does not test satisfactory for coliform organisms, continuous disinfection may be recommended to the homeowner if the water supply is found to be suitable for continuous disinfection. A minimum of 10 independent samples shall be collected and tested for total coliform using an MPN methodology. To be independent, samples shall be collected no less frequently than one sample per day. The geometric mean of the samples shall be calculated and if the result is less than 100 organisms per 100 ml, the supply shall be considered satisfactory for continuous disinfection.

F. Water treatment. If tests indicate that the water samples test positive for coliform organisms and do not meet the standards described in this section and no other approved source is available, adequate methods of water treatment shall be applied. The treatment device shall be demonstrated to be effective pursuant to subdivision E 3 of this section prior to the issuance of an inspection statement. The district or local health department shall be consulted when treatment is necessary.

G. Conversion of Class IV well to Class III potable well. In order to convert an existing Class IV to a Class III well, the owner shall provide the following information to the local health department.

1. A complete application indicating the intent to convert the well classification.

2. A copy of the existing uniform water well completion report documenting that the well meets Class IIIA, Class IIIB, or Class IIIC construction standards in accordance with this chapter.

3. Confirmation that the well meets separation distance criteria for Class III wells listed on Table 1 of 12VAC5-630-380.

4. A negative bacteria water sample in accordance with subsections D, E, and F of this section.

12 Va. Admin. Code § 5-630-431

Derived from Virginia Register Volume 41, Issue 04, eff. 11/6/2024.

Statutory Authority: §§ 32.1-12 and 32.1-176 of the Code of Virginia.