Virginia Administrative Code › Title 12 - HEALTH › Agency 5 - DEPARTMENT OF HEALTH › Chapter 590 - WATERWORKS REGULATIONS › Section 12VAC5-590-401 - Enhanced filtration and disinfection for Cryptosporidium treatment techniques

Current through Register Vol. 40, No. 24, July 15, 2024
A. A
				waterworks using a surface water source, a GUDI source, or both shall comply
				with the requirements of this section based on their population or if the
				waterworks is a wholesaler, based on the population of the largest waterworks
				in the combined distribution system.
B. The owner shall conduct an initial and a
				second round of source water monitoring for each water treatment plant that
				treats a surface water source, a GUDI source, or both. This monitoring may
				include sampling for Cryptosporidium, E. coli, and turbidity to determine what
				level, if any, of additional Cryptosporidium treatment is required.
1. Initial round of source water monitoring.
				The owner shall conduct the following monitoring on the schedule in subdivision
				B 3 of this section unless the monitoring avoidance criteria in subdivision B 4
				of this section are met.
a. The owner of a
				waterworks serving at least 10,000 people shall sample the source water for
				Cryptosporidium, E. coli, and turbidity at least monthly for 24
				months.
b. The owner of a
				waterworks serving fewer than 10,000 people:
(1) Shall sample the source water for E. coli
				at least once every two weeks for 12 months, or
(2) May avoid E. coli monitoring if the owner
				notifies the department that the owner will monitor for Cryptosporidium as
				described in subdivision B 1 c of this section. The owner shall notify the
				department no later than three months before the date at which the owner is
				otherwise required to start E. coli monitoring.
c. The owner of a waterworks serving fewer
				than 10,000 people shall sample the source water for Cryptosporidium at least
				twice per month for 12 months or at least monthly for 24 months if the owner
				meets one of the following, based on monitoring conducted under subdivision B 1
				b of this section:
(1) For a waterworks using
				source water from a lake or reservoir, the annual mean E. coli concentration is
				greater than 10 E. coli/100 mL.
(2)
				For a waterworks using source water from flowing stream, the annual mean E.
				coli concentration is greater than 50 E. coli/100 mL.
(3) The waterworks does not conduct E. coli
				monitoring as described in subdivision B 1 b of this section.
(4) The waterworks using a GUDI source shall
				comply with the requirements of this subdivision B 1 c based on the E. coli
				level that applies to the nearest surface water body. If no surface water body
				is nearby, the waterworks shall comply based on the requirements that apply to
				a waterworks using source water from a lake or reservoir.
d. For the waterworks serving fewer than
				10,000 people, the department may approve monitoring for an indicator other
				than E. coli under subdivision B 1 b (1) of this section. The department also
				may approve an alternative to the E. coli concentration in subdivision B 1 c
				(1), B 1 c (2), or B 1 c (4) of this section to trigger Cryptosporidium
				monitoring. This approval by the department shall be provided to the owner in
				writing and shall include the basis for the department's determination that the
				alternative indicator or trigger level will provide a more accurate
				identification of whether a waterworks will exceed the Bin 1 Cryptosporidium
				level in subdivision B 1 a of this section.
e. The waterworks may sample more frequently
				than required under this section if the sampling frequency is evenly spaced
				throughout the monitoring period.