Chapter 590. Waterworks Regulations

(Repealed.)

(Repealed.)

All components, materials, and products that will be in contact with source water, partially treated water, finished water, or water treatment chemicals shall comply with NSF/ANSI/CAN Standard 61-2020.Statutory Authority§§ 32.1-12 and 32.1-170 of the Code of Virginia.

A. Preference shall be given to the best available sources of supply that present minimal risks of contamination from point and nonpoint pollution sources that contain a minimum of impurities that may be hazardous to health and that give the greatest potential of ensuring a suffi…

A. A surface water source includes all tributary streams and drainage basins, natural lakes, and artificial reservoirs or impoundments above the point of water supply intake. 1. The quantity of water at the source shall: a. Be adequate to supply the water demand of the service ar…

A. A groundwater source includes all water obtained from drilled wells and springs. Wells and springs shall be protected from contamination during construction. All wells intended to serve a waterworks shall be constructed by a certified water well system provider. All wells shal…

A. The design of water treatment facilities shall depend upon the evaluation of the nature and quality of the particular source water to be treated and the required quality of the finished water. Treatment process selection shall follow the requirements of 12VAC5-590-680. B. The …

A. Plans and specifications shall be submitted for evaluation and approval, as required in Part I (12VAC5-590-200 through 12VAC5-590-220), and shall include: 1. Descriptions of feed equipment, including maximum and minimum feed ranges; 2. Location of feeders, piping layout, and p…

A. Conventional filtration treatment is generally used for surface water sources. It is defined as a series of four processes: coagulation, flocculation, sedimentation, and filtration. The specific design parameters shall consider the water supply characteristics and variability …

(Repealed.)

A. Rapid mixing is the rapid dispersion of chemicals throughout the water to be treated, usually by violent agitation, to promote coagulation. 1. Rapid mix basins or inline static mixers shall be provided. 2. Basins shall be equipped with mechanical mixing devices. Other arrangem…

A. The water treatment plant capacity, source water quality, and filtration process used shall be considered in determining the number and design of sedimentation basins. B. The minimum settling time shall be four hours for water treatment plants employing rapid rate gravity filt…

A. Solids contact units shall be acceptable for combined flocculation and clarification where source water characteristics are not variable and flow rates are uniform. When approved, these units shall be designed for the maximum uniform rate and shall be adjustable to changes in …

A. At least two gravity filter units shall be provided in conventional filtration treatment plants and direct filtration treatment plants. B. Filter loading rates shall not exceed 2.0 gpm/ft2 of filter area for rapid rate filters and shall not exceed 4.0 gpm/ft2 for high rate fil…

A. Direct filtration is defined as a series of treatment processes, including coagulation and filtration but excluding sedimentation. Direct filtration shall be considered only for treatment of high quality and seasonally consistent surface water sources or GUDI sources. B. An in…

A. Diatomaceous earth filtration shall be limited to treatment of a surface water source, a GUDI source, or both with low turbidity and low bacterial contamination, and may be used for iron removal from groundwater. B. Pilot plant study. Installation of a diatomaceous earth filtr…

A. Slow sand filters shall be approved only after a pilot study demonstrates that the water supply contains sufficient nutrients for use of this treatment technology. B. At least two filters shall be provided. In all cases, the filters shall be capable of meeting the design maxim…

A. Applicability. This section pertains to the use of membrane filtration as follows: 1. For pathogen and turbidity log removal credits in accordance with Table 500.1 in 12VAC5-590-500, the use of MF and UF are allowed. 2. For softening, total dissolved solids (TDS) removal, orga…

A. Bag or cartridge filtration shall be limited to treating a surface water source, a GUDI source, or both with low turbidity. B. A pilot plant study shall be conducted on the water to be treated before the installation of a bag or cartridge filter system. C. Bag and cartridge fi…

(Repealed.)

A. Pre-engineered package treatment units are defined as predesigned, factory built, and transported virtually assembled to the operation site. The provisions of 12VAC5-590-290 shall apply. B. General design considerations. 1. A rapid mix unit process shall be provided. The desig…

A. The softening design selected shall be based upon the mineral qualities of the source water and the desired finished water quality in conjunction with requirements for disposal of sludge or brine water, cost of the plant, cost of the chemicals, and the plant location. B. Iron,…

A. Aeration treatment is acceptable for oxidation, separation of gases, or for taste and odor control. General design requirements include the following: 1. The aerated water shall be chlorinated following aeration. 2. The equipment shall incorporate materials resistant to deteri…

A. Iron and manganese control, as used in this section, refers solely to treatment processes designed specifically for this purpose. The treatment process used will depend upon the character of the source water. The selection of one or more treatment processes shall meet specific…

A. The board recommends that all community waterworks in Virginia be optimally fluoridated. Fluoridation feed systems shall be designed to deliver the optimum fluoride ion concentration as determined by the U.S. Department of Health and Human Services. B. Fluoride compounds. Comm…

A. Fluoride removal may be accomplished by blending with a different quality water or by removal treatment. Where fluoride removal is required, the treatment units shall be designed to achieve a finished water fluoride concentration that is below the SMCL. B. Blending. Blended wa…

A. Water that is unstable due either to natural causes or to the treatment applied to the water shall be stabilized. B. Deposition of calcium carbonate film. The desired calcium carbonate film may be obtained by using either soda ash or caustic soda when the alkalinity of the wat…

A. The continuous or periodic treatment of source waters with copper sulfate and other copper compounds to kill algae or other growths shall be controlled to prevent a copper concentration in excess of 1.0 mg/L, as copper, in the finished water leaving the treatment plant. B. Sur…

(Repealed.)

A. Processes for the removal of radionuclides specified as BAT are identified in 40 CFR 141.66. The specific process and equipment proposed for removal of radionuclides shall to the satisfaction of the department have a demonstrated history of successful performance with similar …

(Repealed.)

A. Granular activated carbon (GAC) contactors may be used to adsorb natural organic compounds, taste and odor compounds, and SOCs. The most common applications of GAC contactors in drinking water treatment plants are (i) post-filtration adsorption and (ii) filtration-adsorption, …

A. With the exception of sanitary sewage and flows recycled through the water treatment system, the wastes generated during the operation of water filtration plants constitute industrial wastes and are subject to the State Water Control Law (Chapter 3.1 (§ 62.1-44.2 et seq.) of T…