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HomeMy WebLinkAboutMINUTES - 06071994 - 1.7 (2) y f 1.67 through 1.70 THE BOARD OF SUPERVISORS OF CONTRA COSTA COUNTY, CALIFORNIA Adopted this Order on June 7,1994, by the following vote: AYES: Supervisors Smith, DeSaulnier, Torlakson and Bishop NOES: None ABSENT: Supervisor Powers ABSTAIN: None SUBJECT: CORRESPONDENCE Item No. 1.67 LETTER dated May 20, 1994, from D. Babb, Property Tax Assistance Co., Inc., 2570 Appian Way, Suite 100, Pinole 94564, amending the claim for property taxes filed on behalf of Odama Danville, Ltd. ***REFERRED TO ASSESSOR,TREASURER-TAX COLLECTOR,AND COUNTY COUNSEL 1.68 LETTER dated May 23, 1994, from S. Gordon, 2579 Patra Drive, El Sobrante 94803, requesting investigation of a possible zoning violation on Patra Drive, El Sobrante. ***REFERRED TO BUILDING INSPECTOR 1.69 LETTERS dated May 25, 1994, from R. Lewis, Chair, Riverview Board of Fire Commissioners, 1500 West Fourth Street, Antioch 94509, relative to membership on the Countywide Fire Commission and the status of the proposed new fire station on West Leland Road, Pittsburg. ***REFERRED TO COUNTY FIRE CHIEF 1.70 LETTER dated May 24, 1994, from S. Bilson, Chairman & CEO, ReWater, 438 Addison Avenue,Palo Alto 94301, California,transmitting a copy of the March 8, 1994, amendment to the California Plumbing Code entitled Appendix J, which allows greywater systems for subsurface irrigation, and suggesting that the Board adopt it as the County Code. ***REFERRED TO DIRECTOR,BUILDING INSPECTION, COUNTY COUNSEL AND COUNTY HEALTH OFFICER. cc: Correspondents I hereby certify that this is a true and correct copy of Assessor an action taken and entered on the minutes of the Treasurer-Tax Collector. Board of Sup isors on the date shor�nn,,� ATTESTED: �J4v. 14 C(!t County Counsel of SupHIL ervisors and County of the Btrard Building Inspector �� (� or Fire Chief B� y ,Deputy Health Officer 1. 76 438 Addison Avenue VVV EATER Palo Alto,California 94301 S Y S T E M S, 1 N C. Tel:415-324-1307 Fax:415-321-7868 =E RECEIVED May 24, 1994 EMAN6 1994 Contra Costa Board of Supervisors 651 Pine Street, Room 106 CLERK BOARD OF SUPERVISORS Martinez, CA 94553 CONTRA COSTA CO. Dear Board of Supervisors: We would like you to adopt as your own code the enclosed March 8, 1994, amendment to the California Plumbing Code entitled Appendix J, which allows greywater systems for subsurface irrigation. By adopting this code now, your building inspectors can cooperate with homeowners wishing to install such systems before the hot summer months. Greywater systems are new to inspectors, and their inclination is to refuse to even consider approving such devices and methods. Appendix J is a comprehensive amendment written by the California Department of Water Resources in consultation with the Department of Health Services. It took those agencies over a year and a half to write it, and it provides health and safety protections in all circumstances, while maximizing water reuse. Under Appendix J, homeowners with a greywater system will reuse about half of their water, cut their water costs in half, and reduce their sewage flows about half. As the sponsoring company of the legislation which resulted in Appendix J, ReWater Systems, Inc., welcomes the opportunity to assist your understanding of this new way to conserve water and costs. Sincerely, Wc,,ti • Stephen Wm. Bilson Chairman&CEO G� % California Plumbing Code Title 24, Part 5, California Administrative Code APPENDIX J GRAYWATER SYSTEMS FOR SINGLE FAMILY DWELLINGS Section J-1 Graywater Systems. (General) (a) The provisions of this Appendix shall apply to the construction, alteration and repair of graywater systems for subsurface landscape irrigation. Installations shall be allowed only in single family dwellings. The system shall have no connection to any potable water system and shall not result in any surfacing of the graywater. Except as otherwise provided for in this.Appendix,the provisions of the Uniform Plumbing Code (UPC) shall be applicable to graywater installations. (b) The type of system shall be determined on the basis of location, soil type, and ground water level and shall be designed to accept all graywater connected to the system from the residential building. The system shall discharge into subsurface irrigation fields and may include surge tank(s) and appurtenances, as required by the Administrative Authority. (c) No graywater system, or part thereof, shall be located on any lot other than the lot which is the site of the building or structure which discharges the graywater; nor shall any graywater system or part thereof be located at any point having less than the minimum distances indicated in Table J-1. (d) No permit for any graywater system shall be issued until a plot plan with appropriate data satisfactory to the Administrative.Authority has been submitted and approved. When there is insufficient lot area or inappropriate soil conditions for adequate absorption of the graywater, as determined by the Administrative Authority, no graywater system shall be permitted. The Administrative Authority is a city or county. (e) No permit shall be issued for a graywater system which would adversely impact a geologically sensitive area, as determined by the Administrative Authority. (f) Private sewage disposal systems existing or to be constructed on the premises shall comply with Appendix I of this code or applicable local ordinance. When abandoning underground tanks, Section 1119 of the UPC shall apply. Also, appropriate clearances from graywater systems shall be maintained as provided in Table J-1. The capacity of the private sewage disposal system,including required future areas, shall not be decreased by the existence or proposed installation of a graywater system servicing the premises. (g) Installers of graywater systems shall provide an operation and maintenance manual, acceptable to the Administrative Authority, to the owner of each system. Graywater systems require regular or periodic maintenance. (h) The Administrative Authority shall provide the applicant a copy of this Appendix. Section J-2 Definitions. Graywater is untreated household waste water which has not come into contact with toilet waste. Graywater includes used water from bathtubs, showers,bathroom wash basins, and water from clothes washing machines and laundry tubs. It shall not include waste water from kitchen sinks, dishwashers or laundry water from soiled diapers. Surfacing of graywater means the ponding, running off, or other release of graywater from the land surface. 1 March 8, 1994 Section J-3 Permit. It shall be unlawful for any person to construct, install or alter, or cause to be constructed, installed or altered any graywater system in a building or on a premises without first obtaining a permit to do such work from the Administrative Authority. Section J-4 Drawings and Specifications. The Administrative Authority may require any or all of the following information to be included with or in the plot plan before a permit is issued for a graywater system: (a) Plot plan drawn to scale completely dimensioned, showing lot lines and structures, direction and approximate slope of surface, location of all present or proposed retaining walls, drainage channels,water supply lines,wells,paved areas and structures on the plot, number of bedrooms and plumbing fixtures in each structure, location of private sewage disposal system and 100% expansion area or building sewer connecting to public sewer, and location of the proposed graywater system. (b) Details of construction necessary to ensure compliance with the requirements of this Appendix together with a full description of the complete installation including installation methods, construction and materials as required by the Administrative Authority. (c) A log of soil formations and ground water level as determined by test holes dug in close proximity to any proposed irrigation area, together with a statement of water absorption characteristics of the soil at the proposed site as determined by approved percolation tests. In lieu of percolation tests, the Administrative Authority may allow the use of Table J-2, an infiltration rate designated by the Administrative Authority,or an infiltration rate determined by a test approved by the Administrative Authority. Section J-5 Inspection and Testing. (a) Inspection 1. All applicable provisions of this Appendix and of Section 318 of the UPC shall be complied with. 2. System components shall be properly identified as to manufacturer. 3.. Surge tanks shall be installed on dry,level,well-compacted soil if in a drywell,or on a level, 3" concrete slab or equivalent, if above ground. 4. Surge.tanks shall be anchored against overturning. 5. If the irrigation design is predicated on soil tests,the irrigation field shall be installed at the same location and depth as the tested area. 6. Installation shall conform with the equipment and installation methods identified in the approved plans. 7. Graywater stub-out plumbing may be allowed for future connection prior to the installation of irrigation lines and landscaping. Stub-out shall be permanently marked "GRAYWATER STUB-OUT,DANGER-UNSAFE WATER' (b) Testing 1. Surge tanks shall be filled with water to the overflow line prior to and during inspection. All seams and joints shall be left exposed and the tank shall remain watertight. 2. A flow test shall be performed through the system to the point of graywater irrigation. All lines and components shall be watertight. Section J-6 Procedure for Estimating Graywater Discharge. The Administrative Authority may utilize the graywater discharge procedure listed below, water use records,or calculations of local daily per person interior water use: 2 March 8, 1994 . .. •tit 1 �a)' The number of occupants of each dwelling unit shall be calculated as follows: First Bedroom 2 occupants Each additional bedroom 1 occupant (b) The estimated graywater flows for each occupant shall be calculated as follows: Showers,bathtubs and wash basins 25 GPD/occupant. Laundry 15 GPD/occupant. (c) The total number of occupants shall be multiplied by the applicable estimated graywater discharge as provided above and the type of fixtures connected to the graywater system. Section J-7 Required Area of Subsurface Irrigation. Each irrigation zone shall have a minimum effective irrigation area for the type of soil and infiltration rate to distribute all graywater produced daily,pursuant to Section J-6, without surfacing. The required irrigation area shall be based on the estimated graywater discharge, pursuant to Section J-6 of this Appendix, size of surge tank, or a method determined by the Administrative Authority. Each proposed graywater system shall include at least two irrigation zones and each irrigation zone shall be in compliance with the provisions of this Section. If the mini-leachfield irrigation system is used, the required square footage shall be determined from Table J-2, or equivalent, for the type of soil found in the excavation. The area of the irrigation field shall be equal to the aggregate length of the perforated pipe sections within the irrigation zone times the width of the proposed mini-leachfield trench. No irrigation point shall be within five vertical feet of highest known seasonal groundwater nor where graywater may contaminate the ground water or ocean water. The applicant shall supply evidence of ground water depth to the satisfaction of the Administrative Authority. Section J-8 Determination of Irrigation Capacity. (a) In order to determine the absorption quantities of questionable soils other than those listed in Table J-2, the proposed site may be subjected to percolation tests acceptable to the Administrative Authority or determined by the Administrative Authority. (b) When a percolation test is required,no mini-leachfield system or subsurface drip irrigation system shall be permitted if the test shows the absorption capacity of the soil is less than 60 minutes/inch or more rapid than 5 minutes/inch, unless otherwise permitted by the Administrative Authority. (c) The irrigation field size may be computed from Table J-2, or determined by the Administrative Authority or a designee of the Administrative Authority. Section J-9 Surge Tank Construction. (FIG. 1,2,3 &.4) (a) Plans for surge tanks shall be submitted to the Administrative Authority for approval. The plans shall show the data required by the Administrative Authority and may include dimensions,structural calculations,and bracing details. (b) Surge tanks shall be constructed of solid, durable materials,not subject to excessive corrosion or decay and shall be watertight. (c) Surge tanks shall be vented as required by Chapter 5 of this Code and shall have a locking, gasketed access opening, or approved equivalent, to allow for inspection and cleaning. (d) Surge tanks shall have the rated capacity permanently marked on the unit. In addition, "GRAYWATER IRRIGATION SYSTEM,DANGER-UNSAFE WATER"shall be permanently marked on the surge tank. 3 March 8, 1994 s . (e) Surge tanks installed above ground shall have a drain and overflow, separate from the line connecting the tank with the irrigation fields. The drain and overflow shall have a permanent connection to a sewer or to a septic tank, and shall be protected against sewer line backflow by a backwater valve. The overflow shall not be equipped with a shut-off valve. (f) The overflow and drain pipes shall not be less in diameter than the inlet pipe. The vent size shall be based on the total graywater fixture units,as outlined in UPC Table 4-3 or local equivalent. Unions or equally effective fittings shall be provided for all piping connected to the surge tank. (g) Surge tanks shall be structurally designed to withstand anticipated loads. Surge tank covers shall be capable of supporting an earth load of not less than 300 pounds per square foot when the tank is designed for underground installation. (h) Surge tanks may be installed below ground in a dry well on compacted soil,or buried if the tank design is approved by the Administrative Authority. The system shall be designed so that the tank overflow will gravity drain to a sanitary sewer line or septic tank. The tank must be protected against sewer line backflow by a backwater valve. (i) Materials 1. Surge tanks shall meet nationally recognized standards for non-potable water and shall be approved by the Administrative Authority. 2. Steel surge tanks shall be protected from corrosion,both externally and internally,by an approved coating.or by other acceptable means, Section J-10 Valves and Piping. (FIG. 1,2,3 &4) Graywater piping discharging into a surge tank or having a direct connection to a sanitary drain or sewer piping shall be downstream of an approved waterseal type trap(s). If no such trap(s) exists, an approved vented running trap shall be installed upstream of the connection to protect the building from any possible waste or sewer gasses. All graywater piping shall be marked or shall have a continuous tape marked with the words "DANGER-UNSAFE WATER." All valves, including the three-way valve,shall be readily accessible and shall be approved by the Administrative Authority. A backwater valve,installed pursuant to this Code,shall be provided on all surge tank drain connections to.the sanitary drain or sewer piping. Section J-11 Irrigation Field Construction. The Administrative Authority may permit subsurface drip irrigation,mini-leachfield or other equivalent irrigation methods which discharge graywater in a manner which ensures that the graywater does not surface. Design standards for subsurface drip irrigation systems and mini-leachfield irrigation systems follow: . f- (a) Standards for a subsurface drip irrigation system are: 1. Minimum 140-mesh(115 micron) one inch filter with a capacity of 25 gallons per minute, or equivalent,filtration shall be used. The filter back-wash and flush discharge shall be caught,contained and disposed of to the sewer system,septic tank,or with approval of the Administrative Authority,a separate mini-leachfield sized to accept all the back-wash and flush discharge water. Filter backwash water and flush water shall not be used for any purpose. Sanitary procedures shall be followed when handling filter back-wash and flush discharge or graywater. 2. Emitters shall have a minimum flow path of 1200 microns and shall have a coefficient of. manufacturing variation (Cv) of no more than seven percent. Irrigation system design 4 March 8, 1994 ► 1 shall be such that emitter flow variation shall not exceed plus or minus ten percent. Emitters shall be recommended by the manufacturer for subsurface use and graywater use, and shall have demonstrated resistance to root intrusion. For emitter ratings refer to: Irrigation Equipment Performance Report, Drip Emitters and Micro-Sprinklers, Center for Irrigation Technology, California State University, 5730 N. Chestnut Avenue, Fresno, California 93740-0018. 3. Each irrigation zone shall be designed to include no less than the number of emitters specified in Table J-3, or through a procedure designated by the Administrative Authority. Minimum spacing between emitters is 14 inches in any direction. 4. The system design shall provide user controls, such as valves,switches, timers, and other controllers as appropriate, to rotate the distribution of graywater between irrigation zones. 5. All drip irrigation supply lines shall be PVC class 200 pipe or better and schedule 40 fittings. All joints shall be properly glued, inspected and pressure tested at 40 psi, and shown to be drip tight for five minutes,before burial. All supply lines will be buried at least eight inches deep. Drip feeder lines can be poly or flexible PVC tubing and shall be covered to a minimum depth of nine inches. 6. Where pressure at the discharge side of the pump exceeds 20 pounds per square inch (psi), a pressure reducing valve able to maintain downstream pressure no greater than 20 psi shall be installed downstream from the pump and before any emission device. 7. Each irrigation zone shall include an automatic flush valve/vacuum breaker to prevent back syphonage of water and soil. (b) Standards for the mini-leachfield system are: (FIG. 5) 1. Perforated sections shall be a minimum 3-inch diameter and shall be constructed of perforated high density polyethylene pipe, perforated ABS pipe, perforated PVC pipe, or other approved materials,provided that sufficient openings are available for distribution of the graywater into the trench area. Material, construction and perforation of the piping shall be in compliance with the appropriate absorption field drainage piping standards and shall be approved by the Administrative Authority. 2. Clean stone, gravel,or similar filter material acceptable to the Administrative Authority, and varying in size between 3/4 inch to 21/2 inches shall be placed in the trench to the depth and grade required by this Section. Perforated sections shall be laid on the filter material in an approved manner. The perforated sections shall then be covered with filter material to the minimum depth required by this Section. The filter material shall then be covered with landscape filter fabric or similar porous material to prevent closure of voids with earth backfill. No earth backfill shall be placed over the filter material cover until after inspections and acceptance. . 3. Irrigation fields shall be constructed as follows: MINIMUM MAXIMUM Number of drain lines per irrigation zone 1 --- Length of each perforated line --- 100 feet Bottom width of trench 6 inches 18 inches Total depth of trench 17 inches 18 inches Spacing of lines, center to center 4 feet --- Depth of earth cover of lines 9 inches --- Depth of filter material cover of lines 2 inches --- Depth of filter material beneath lines 3 inches --- Grade of perforated lines level 3 inches/100 feet 5 March 8, 1994 . , . . Section J-12 Special Provisions . (a) Other collection and distribution systems may be approved by the Administrative Authority as allowed by Section.201 of the UPC. (b) Nothing contained in this Appendix shall be construed to prevent the Administrative Authority from requiring compliance with stricter requirements than those contained herein, where such stricter requirements are essential in maintaining safe and sanitary conditions or from prohibiting graywater systems. Section J-13 Health and Safety (a) Graywater may contain fecal matter as a result of bathing and/or washing of diapers and undergarments. Water containing fecal matter, if swallowed, can cause illness in a susceptible person. (b) Graywater shall not include laundry water from soiled diapers. (c) Graywater shall not be applied above the land surface or allowed to surface and shall not be discharged directly into or reach any storm sewer system or any water of the United States. (d) Graywater shall be not be contacted by humans, except as required to maintain the graywater treatment and distribution system. (e) Graywater shall not be used for vegetable gardens. 6 March 8, 1994 , Table J-1 Location of Graywater System Minimum Horizontal Distance (in feet)From Surge Tank Irrigation Field Buildings or structures' S ft' 8 ft' Property line adjoining private property 5 ft 5 ft Water supply wells4 50 ft 100 ft . Streams and lakes4 50 ft 50 ft Seepage pits or cesspools 5 ft 5 ft Disposal field& 100% expansion area 5 ft 4 ft5 Septic tank 0 ft 5 ft6 On-site domestic water service line 5 ft 5 ft' Pressure public water main loft 10 ft, Water ditches 50 ft 50 ft Notes: When mini-leach fields are installed in sloping ground, the minimum horizontal distance between any part of the distribution system and ground surface shall be fifteen feet. 1. Including porches and steps,whether covered or uncovered,but does not include car ports,covered walks, driveways and similar structures. 2. The distance may be reduced to zero feet for above ground tanks if approved by the Administrative Authority. 3. The distance may be reduced to two feet, with a water barrier,by the Administrative Authority, upon consideration of the soil expansion index. 4. Where special hazards are involved,the distance may be increased by the Administrative Authority. 5. Applies to the mini-leachfield type system only. Plus two feet for each additional foot of depth in excess of one foot below the bottom of the drain line. 6. Applies to mini-leachfield type system only. 7. A two foot separation is required for subsurface drip systems. 8. For parallel construction or for crossings,approval by the Administrative Authority shall be required. Table J-2 Mini-Leach Field Design Criteria of Six Typical Soils. Type of Soil Minimum sq. ft. of irrigation Maximum absorption capacity, area per 100 gallons of estimated minutes per inch,of irrigation graywater discharge per day. area for a 24-hour period. 1. Coarse sand or gravel 20 5 2. Fine sand 25 12 3. Sandy loam 40 18 4. Sandy clay 60 24 5. Clay with considerable sand or gravel 90 48 6. Clay with small amount of sand or gravel 120 60 Table J-3 Subsurface Drip Design Criteria of Six Typical Soils. Type of Soil Maximum emitter Minimum number of emitters discharge(gal/day) per gpd of graywater production 1. Sand 1.8 .6 2. Sandy loam 1.4 .7 3. Loam 1.2 .9 4. Clay loam .9 1.1 5. Silty clay .6 1.6 6. Clay .5 2.0 Use the daily graywater flow calculated in Section J-6 to determine the number of emitters per line 7 March 8, 1994 P GRAYWATER SYSTEM Single Tank - Gravity (conceptual) Screened vents 3/32"mesh Vent shall be within / trap arm distance of VTR or 10'above grade Union or equal(TYP) running trap (support required) Locking Cover(access) 3-way valve Graywater / Inlet _ Approved water tight tank source 0 O O 0 1/4"/FT / Overflow Graywater Fullway Valve Vented running trap, (no Valve Irrigation System if required San Tee Fullway Valv Danger Grade Unsafe Water Grade Wye& 1/8 Bend � Drain(N.C.) � � Backwater Valve / To Irrigation system C/O 3"Concrete Pad or equivalent Minimum of two 1/4"/FT irrigation lines required To building drain,sewer, or septic tank,if any Abbreviations C/O Cleanout N.C. Normally Closed VTR Vent Thru Roof California Plumbing Code Figure 1 Appendix J Date: March 1994 Revised: Final f � GRAYWATER SYSTEM Single Tank Pumped (conceptual) Screened vents 3/32"or less Vent shall be within \ / Approved water tight tank with locking cover trap arm distance of VTR or 10'above grade pp g g running trap (support required) \ Backwater Valve 3-way valve JLL Graywater I Inlet Shut-off valve source / O 1/4"/Fr / 1 / Union or equal Overflow Gra'water Vented running trap, (no Valve Irrigation System if required Fullway DangerGrade San Tee\ Valy U We� er Grade\ — / Wye& 1/8 Bend Drain(N.C.) � ======I I C/O 3"Concrete Pad To Irrigation system 1/4"/FF Backwater Valve or equivalent Minimum of two To building drain, Pump irrigation lines required sewer,or septic tank Abbreviations C/O Cleanout N.C. Normally Closed VTR Vent Thru Roof California Plumbing Code Figure 2 Appendix J Date: March 1994 Revised: Final 3 t• • Sr GRAYWATER SYSTEM Multiple Tank (conceptual) Screened vents 3132"mesh Vent shall be within trap arm /� distance of ~ �" running trap VTR or 10'above grade (support required) 6"above top of highest tank Union or equal 3-way valve Locking Cover Graywater ` Inlet source M eApproved water tight tank overflow Graywater Overflow Graywater Fullway Valve Vented running trap, (no valve) Irrigation System (no Valve) Irrigation System if required Danger Danger Grade San Tee . _ Unsafe Water Unsafe Water Grade Wye& 1/8 Bend Drain(N.C.) C!Q ` ,� To Irrigation system �» 1/4"/FT Backwater Valve 3"Concrete Pad Minimum of two irrigation To building drain, or equivalent lines required sewer,or septic tank Abbreviations C/O Cleanout N.C. Normally Closed VTR Vent Thru Roof California Plumbing Code Figure 3 Appendix J Date: March 1994 Revised: Final V 1 • tY A GRAYWATER SYSTEM Underground Tank (conceptual) Vent shall be within trap arm distance of running trap Screened vent 3/32"mesh VTR or 10'above grade (support required) Backwater Valve Vented running trap, Union or equal Shut-off valve if required 3-way valve Inlet Graywater To Irrigation system source 1/4°/F1 I ' I Minimum of two irrigation lines required own Grade\\ Iv; Q Wye& 1/8 Bend ` y Locking cover Backwater Valve 1/4"/Fr / 4-11 Overflow / Water tight tank approved 1/4"/Fr C/O (no vent) 1 / for underground use To building drain, r1 r`1 sewer,or septic tank \ / Pump Capped drain Sign on top of tank Graywater Irrigation System DANGER UNSAFE WATER Abbreviations C/O Cleanout VTR Vent Thru.Roof California Plumbing Code Figure 4 Appendix J Date: March 1994 Revised: Final Y y ' GRAYWATER SYSTEM Irrigation Layout (conceptual). To public vent Thru Roof sewer b PL x Min PL PL " 5'Min Distributing valve pr perry Line Nb Drip irrigation zone Note: each irrigation zone shall have a minimum effec- tive irrigation area based on Section J-7.. Soil Gravel Grade filter fabric 2" •�.• .'� " : .'� or equivalent 17„ Min. 3” %i `•` �. 3"(minimum)perforated pipe section California Plumbing Code Figure 5 Appendix � Date: March 1994 Revised: Final t . r �. .'►•rte. t?O t•1 ReuseR or lose Your home produces enough water to irrigate ' -• - ' most of your landscape. R s Discover ReWater System . The state approved technology that automatically reuses shower,tubs and clothes washer water for your landscape irrigation. Benefits to You: Enjoy long showers knowing the water is going into your landscape. Economic Permanently reduce your water bill by about 45%. Monthly water savings pays for your system. In-house financing available. Lessen drought vulnerability. 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