Virginia Administrative Code › Title 12 - HEALTH › Agency 5 - DEPARTMENT OF HEALTH › Chapter 630 - PRIVATE WELL REGULATIONS › Part III - Design and Construction Criteria › Article 1 - General Requirements › Section 12VAC5-630-370 - Water quality and quantity

Current through Register Vol. 40, No. 24, July 15, 2024
A.
					 Class IV wells exempt. The water quality requirements contained in this section
					 apply only to Class III private wells. Class IV private wells (wells not
					 constructed as a source of drinking water) are not subject to any quality
					 requirements. These regulations contain no well yield requirements. See
					 12VAC5-630-460 for suggested
					 minimum well yields for residential supplies.
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 (12VAC5-630-430 and
					 12VAC5-630-470 ).
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, well driller, or other person in accordance with procedures established
					 by the department and provided the sample is submitted to a private laboratory
					 certified 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(s) test(s) negative
					 for coliform organisms as described in subdivision 1 or 2 below. Sources with
					 positive counts shall be tested as described in subdivision 3 below to
					 determine if the water supply is amenable to continuous disinfection
					 (chlorination). Samples that exhibit confluent growth shall be considered
					 inconclusive and another sample shall be collected.
1. Where 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. Where 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 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 samples shall be collected and tested for total
					 coliform using an MPN methodology. 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.