West Virginia Code of State Rules › Agency 64 - Health › Title 64 - LEGISLATIVE RULE WEST VIRGINIA DEPARTMENT OF HEALTH AND HUMAN RESOURCES › Series 64-47 - Sewage Treatment and Collection System Design Standards › Section 64-47-5 - Sewage Treatment Works

Current through Register Vol. XLI, No. 28, July 12, 2024
5.1.
				General.
5.1.a. The design of sewage
				treatment plants shall be to provide for an estimated population on July 1,
2042
. The design of all treatment plants shall be so
				that their capacity can readily be increased except when circumstances preclude
				the probability of expansion.
5.1.b. Plant Location. A sewage treatment
				plant site shall be as far as practical from any present area being built-up or
				any area that shall probably be built up within a reasonable future period.
				There shall be a buffer zone as indicated in Table 64-47-E. at the end of this
				rule, from any surrounding occupied structure to any new plant site. These
				buffer zone requirements do not apply to existing treatment works that are
				being upgraded or expanded. The direction of prevailing winds shall be
				considered when selecting the plant site. The location of the plants
				operational units shall be at an elevation that is not subject to the 100-year
				flood or shall otherwise be adequately protected against 100-year flood damage.
				The plant shall remain fully operational during a 25-year flood. The plant
				shall be readily accessible in all seasons. The site shall be of sufficient
				size to accommodate expansion or addition of facilities to increase the degree
				of treatment.
5.1.b.1. The Commissioner may
				wave buffer zone requirements shown in Table 64-47-E. upon receipt of a written
				request by the applicant and a detailed review by the Commissioner to determine
				any public health impact. Health, safety, and nuisance considerations shall be
				the basis of establishing a buffer zone.
5.1.b.2. The distances set forth in Table
				64-47-E. are distances to sewage treatment units such as aeration basins,
				clarifiers, sludge holding tanks, chlorination basins, chlorinator rooms,
				blower houses and other units as stated in Table 64-47-E. Other buildings that
				may be part of the plant but are only used for storage or as a laboratory and
				do not contain chlorine cylinders or blowers, shall not be considered a sewage
				treatment unit and shall not be subject to buffer zone requirements.
5.1.c. Quality of Effluent.
5.1.c.1. Surface Water Discharge. The stream
				standards and water quality criteria established by the water resources board
				and effluent limitations established by the division of water resources shall
				be the basis of the required degree of wastewater treatment. The Commissioner
				may establish more stringent requirements if the location of a public water
				supply intake, a recreational water use area, or an aquaculture is downstream
				from the discharge point.
5.1.c.2.
				Land Discharge. See subsection 5.19 of this rule.
5.1.c.3. New Processes, Methods and
				Equipment. The policy of the Commissioner is to encourage the development of
				new processes, methods, and equipment for sewage treatment. The Commissioner
				may require the following:
5.1.c.3.A.
				Monitoring observations, including test results and engineering evaluations,
				demonstrating the efficiency of these processes;
5.1.c.3.B. Detailed description of the test
				methods;
5.1.c.3.C. Testing,
				including appropriately composited samples, under various ranges of strength
				and flow rates, including daily variations, and waste temperatures over a
				sufficient length of time to demonstrate performance under climatic and other
				conditions that the system may encounter in the area of the proposed
				installations;
5.1.c.3.D. Testing
				and evaluations made under the supervision of a competent process engineer
				other than those employed by the manufacturer or developer; and
5.1.c.3.E. A performance bond.
5.1.d. Design.
5.1.d.1. Industrial Wastes. When treating
				industrial and institutional wastes in a sewage treatment works, the character
				of the wastes in the design of the plant shall be considered. In these cases,
				the Commissioner may require treatability studies on the composite wastewater
				prior to the plant design.
5.1.d.2.
				Hydraulic Loading. The design of treatment plant units shall be based on the
				average rate of sewage flow per 24 hours, except where there are notations of
				significant deviations from the normal daily flow pattern.
5.1.d.3. Existing Sewage Systems. When there
				are existing sewers, there shall be a determination as to the volume and
				strength of sewage flow. Obtaining these data shall be from actual flow
				measurements, preferably for both wet and dry weather periods. There shall be
				laboratory analysis made on flow proportional composite samples taken over
				24-hour periods. The design of plans and specifications for sewage works to
				serve existing sewage systems shall be on the basis of characteristics and
				strength of sewage as shown by results of composite samples examined and
				gaugings of the present flow plus allowance for estimated increase in
				population. In addition, they shall include non-excessive
				infiltration/inflow.
5.1.d.4. New
				Sewage Systems. For the construction of new sewers, design plans for sewage
				treatment works shall be made on the basis of 70 gallons per capita per day or
				estimates based upon a minimum one yearfully documented analysis of water use
				records adjusted for consumption and losses.
5.1.d.5. Organic Loading. Computation of the
				design organic loading shall be in the same manner used in determining design
				flow. Generally, computation of organic loading shall be at 0.17 pounds of
				five-day BOD per person per day. For package sewage treatment plants,
				recirculating sand filter systems, stabilization ponds, aerated ponds, and
				individual sewer systems, treating 50,000 G.P.D. or less, the organic loading
				design shall increase if proposing garbage grinders.
5.1.d.6. Conduits. The design of all piping
				and channels shall be to carry the maximum expected flows. The design of the
				incoming sewer shall be for free discharge. Filleting bottom corners of the
				channels is required. Eliminating pockets and corners where solids can
				accumulate is also required. There shall be suitable gates in channels to seal
				off unused sections that might accumulate solids. The use of shear gates or
				stop planks shall receive approval when using them in place of gate valves or
				sluice gates.
5.1.d.7. Arrangement
				of Units. Arrangement of component parts of the plant shall be for greatest
				operating convenience, flexibility, economy, and so as to facilitate
				installation of future units. There shall be multiple treatment units for
				plants greater than 100,000 gallons in size. There shall be a provision for
				appurtenances in such a manner that it is possible to temporarily take any unit
				of service. The remainder of the plant shall be operational with the unit or
				units out of service. In the case of oxidation ditches, if multiple rotors
				exist, the above requirements shall be met.
5.1.e. Miscellaneous.
5.1.e.1. Provisions for Taking Units Out of
				Service. Diversion piping and structures shall be properly located and arranged
				so that it is possible to independently remove either dual or multiple units of
				the plant from service for inspection, maintenance, and repairs.
5.1.e.2. Dewatering. There shall be means to
				dewater each unit. The possible need for hydrostatic pressure relief devices
				shall be considered.
5.1.e.3.
				Construction Materials. Because of the possible presence of hydrogen sulfide
				and other corrosive gases, greases, oils, and similar constituents frequently
				present in sewage, the materials selected for use in sewage treatment works
				shall be considered. This is particularly important in the selection of metals
				and paints. It is essential to avoid using dissimilar metals to minimize
				galvanic action. Cathodic protection is a requirement for all steel
				tanks.
5.1.e.4. Covering Units. The
				use of properly vented covers shall receive approval.
5.1.e.5. Painting. It is important to avoid
				the use of paints containing lead or mercury. In order to facilitate
				identification of piping, this rule suggests that the different lines be
				color-coded. The contents shall be stenciled on the piping in a contrasting
				color. The color scheme is only required for plants of over 100,000 gallons in
				size. For purposes of standardization, Table 64-47-F. at the end of this rule
				contains the recommended color scheme.
5.1.e.6. Operating Equipment. The
				specifications shall include a complete outfit of tools and accessories for the
				plant operator's use, such as squeegees, wrenches, valve keys, rakes, shovels,
				etc. A portable pump is recommended. There shall be readily accessible storage
				space and work bench facilities and consideration given to provision of a
				garage area that would also provide space for large equipment, maintenance, and
				repair.
5.1.e.7. Grading and
				Landscaping. There shall be concrete, asphalt or gravel walkways for access to
				all units. Where possible, it is important to avoid steep slopes to prevent
				erosion. Surface water shall not drain into any unit. There shall be particular
				care taken to protect trickling filter beds, sludge beds, and intermittent sand
				filters from surface water. There shall be a provision for landscaping,
				particularly when a plant location must be near residential areas.
5.1.f. Plant Outfalls.
5.1.f.1. Outlet. The outfall sewer, where
				practical, shall extend to the low water level of the receiving body of water
				in a manner to insure satisfactory dispersion of the effluent. It shall not
				have its outlet submerged and there must be provisions for taking samples of
				the effluent discharge. This rule permits the use of headwalls where adequate
				dispersion is obtained without carrying the outfall into the stream.
5.1.f.2. Design and Construction. The
				construction of the outfall sewer shall be as to protect it against the effects
				of flood water, ice, or other hazards as to reasonably insure its structural
				stability and freedom from stoppage.
5.1.g. Essential Facilities.
5.1.g.1. Emergency Power.
5.1.g.1.A. General. All sewage treatment
				facilities greater than 100,000 gallons in size that require electrical power,
				shall have an alternate source of electric power to allow continuity of
				operation during power failures, except as noted below. Methods of providing
				alternate sources include:
5.1.g.1.A.1. The
				connection of at least two independent public utility sources, such as
				substations. This rule recommends a power line from each substation, and it
				shall be a requirement unless the reviewing agency receives verifying
				documentation and approves that a duplicate line is not necessary to minimize
				water quality violations;
5.1.g.1.A.2. Portable or in-place internal
				combustion engine equipment that shall generate electrical or mechanical
				energy; and
5.1.g.1.A.3. Portable
				pumping equipment when only emergency pumping is required.
5.1.g.1.B. Power for Aeration. Standby
				generating capacity is not a requirement for aeration equipment used in the
				activated sludge process. When power outages of four hours or more are common,
				auxiliary power for minimum aeration of the activated sludge is a requirement.
				The reviewing authority may require full power generating capacity on certain
				critical stream segments.
5.1.g.1.C. Power for Disinfection. There
				shall be continuous disinfection, when required, during all power
				outages.
5.1.g.2.
				Electrical Equipment. The location of all electrical equipment such as motors
				and local controls, and electrical conduits shall either be at an elevation
				above the 100-year flood level or be of waterproof design. There shall be
				adequate protection for all outdoor equipment from the weather. Motors located
				indoors, and near liquid handling piping and equipment, shall be of splashproof
				design. All electrical wires in underground conduits or in conduits that can
				flood shall have water resistant insulation as identified in the National
				Electrical Code.
5.1.g.3. Water
				Supply.
5.1.g.3.A. General. There shall be an
				adequate supply of drinking water for use in the laboratory and general
				cleanliness around the plant. No piping or other connections shall exist in any
				part of the treatment works that, under any condition, might cause the
				contamination of a drinking water supply. There shall be an examination of the
				chemical quality for suitability for the intended use in heat exchangers,
				chlorinators, and other units.
5.1.g.3.B. Direct Connections. The drinking
				water supply line to each treatment plant shall have, as a minimum, an approved
				reduced pressure type backflow preventer. The installation of these devices
				shall be in a location to prevent flooding, corrosion and allow for adequate,
				quick service and periodic inspections. Installation in below-grade meter type
				vaults is not acceptable. All water supply take-off points shall follow the
				devices and, there shall be no allowance for extension of this line to serve
				the public.
5.1.g.3.C. Indirect
				Connection. When using a potable water supply for any purpose in a plant, there
				shall be provisions for a break tank, pressure pump, and pressure tank. Water
				shall discharge to the break tank through an air-gap at least six inches above
				the maximum flood line or the spill line of the tank, whichever is higher.
				There shall be a permanently posted sign at every hose bibb, faucet, or stop
				clock located on the water system beyond the break tank to indicate that the
				water is not safe for drinking.
5.1.g.3.D. Separate Drinking Water Supply.
				When it is not possible to provide drinking water from a public water supply,
				there shall be a separate well. Location, construction, and testing of the well
				shall comply with requirements of the Bureau. Requirements governing the use of
				the supply are those contained in subparagraphs 5.1.g.3.B. and 5.1.g.3.C. of
				this rule. Prior to construction, an applicant shall obtain approval of the
				supply from the Commissioner.
5.1.g.3.E. Separate Non-Drinking Water
				Supply. When there is a provision for a separate non-drinking water supply,
				there shall be posting of a permanent sign indicating the water is not safe for
				drinking to stop cocks, hose bibbs, and other water outlets.
5.1.g.4. Sanitary Facilities. All
				sewage treatment plants with laboratory facilities shall have a shower, toilet,
				and lavatory. There shall also be a provision for locker facilities.
5.1.g.5. Sewage Flow Measurement. There shall
				be facilities for measuring the volume of sewage flows at all treatment works
				greater than 100,000 gallons in size. All plants having a capacity of greater
				than 100,000 gallons per day shall equip indicating, recording, and totalizing
				equipment for effluent flow measurement.
5.1.g.6. Floor Slope. There shall be adequate
				floor surface slope to a point of drainage.
5.1.g.7. Stairways. The installation of
				stairways shall be with a slope of 30 to 35 degrees from the horizontal to
				facilitate carrying samples, tools, and other necessaries. All risers in a
				stairway should be of equal height. All stairways shall have
				handrails.
5.1.h. Safety.
				Following are the minimum requirements for all plants:
5.1.h.1. Enclosure of the wastewater
				treatment works with a minimum six feet high chain link fence with a locked
				entrance gate designed to discourage the entrance of unauthorized persons and
				animals. In lieu of a chain link fence, a barbed wire fence with a locked
				entrance gate can enclose natural systems, such as stabilization ponds,
				polishing ponds, and wetlands.
5.1.h.2. There shall be handrails, grating,
				and guardrails installed for safety when installed in open basins, screen
				channels, mechanical equipment, and other hazardous places. For all extended
				aeration plants of 50,000 gallons per day or less grating is a
				requirement.
5.1.h.3. Provision of
				first-aid equipment.
5.1.h.4.
				Posting of "No Smoking" signs in hazardous locations.
5.1.h.5. Provision of protective clothing and
				equipment such as SCBA's, atmospheric testers and gloves.
5.1.h.6. Provision of portable blower and
				sufficient hose.
5.1.h.7. There
				shall be explosion proof electrical equipment and non-sparking tools in work
				areas where hazardous conditions may exist, such as digester vaults and other
				locations where potentially explosive atmospheres of flammable gas or vapor
				accumulate.
5.1.h.8. Proper
				grounding and insulation of all electrical wiring is a requirement. There shall
				be no part of the plant piping used for grounding.
5.1.h.9. There shall be a provision for
				portable lighting equipment.
5.1.h.10. All manhole steps shall have
				slip-proof rungs and the steps shall be of the railroad type that shall help
				prevent foot slippage off the ends of the rungs.
5.1.h.11. There shall be a provision for
				separate storage located remotely from the plant for flammable and hazardous
				material.
5.1.h.12. The location of
				heating devices with open flames shall be in separate rooms with outside
				entrances and at grade or above.
5.1.h.13. Installation of particular safety
				precautions for gas-collection piping is a requirement.
5.1.h.14. There shall be adequate
				ventilation.
5.1.h.15. Chlorinator
				rooms and chlorine storage areas shall have heat, light, and a ventilation fan
				that is capable of being turned on from outside the room. The room shall be at
				grade or above. There shall be a provision a viewing window from the plant
				interior; and
5.1.h.16. The
				treatment works shall comply with the provisions of the Occupational Safety and
				Health Act (OSHA).
5.1.i.
				Laboratory Space. All treatment works shall have facilities, either contractual
				or on-site, for making the necessary analytical determinations and operating
				control tests. When using an on-site laboratory, isolation shall be done to
				render the laboratory reasonably free from the adverse effects of noise, heat,
				vibration, and dust. Minimum laboratory space for facilities not performing BOD
				and suspended solids testing on-site shall be 100 square feet floor space with
				35 square feet bench area. Facilities providing on-site BOD, suspended solids,
				and fecal coliform analysis shall provide a minimum of 400 square feet of floor
				space and 150 square feet of bench space. If more than two persons shall be
				working in the laboratory at any given time, there shall be a provision of 100
				square feet of additional space for each additional person. Advanced wastewater
				treatment plants shall provide a minimum of 100 additional square feet of floor
				space with proportionate increase in bench space. Lists of laboratory equipment
				shall be compiled from USEPA approved latest edition of Standard Methods for
				the Examination of Water & Wastewater, by APHA - AWWA - WPCF.
5.1.j. Laboratory Equipment. All treatment
				works shall have laboratory equipment determined by the commissioner based upon
				type and complexity of the treatment process. However, all extended aeration
				treatment plants of 100,000 gallons per day or less shall have the following:
5.1.j.1. A test kit for pH and for chlorine
				residual. This test kit shall be of the comparator type as manufactured by
				Hach, Taylor, Hellige, or Wyandotte;
5.1.j.2. Two one-liter graduated
				beakers;
5.1.j.3. A secchi disk;
				and
5.1.j.4. A squeegee with proper
				length of handle, five-quart bucket and rubber gloves.