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HomeMy WebLinkAbout77-124RESOLUTION E~TABLI3HZNG WELL CONSTRUCT~ON AND DESTTtUCTION STANDARDS AND SETTING PERMLT FEES PURSUANT TO CHAT'TER 23S OF THE BUTTE COUNTY CODE WHEREAS, pursuant to the provisions of Chapter 23 B of the Butte County Code certain standards governing well construction, repair, reconstruction and destruction and fee schedules are to be establisfied by resolution by the Soard of Supervisors of the County of Bntte. NOW, THEREFORE BE IT RESOLVED by the Butte County Board of Supervisors as follows: Section Io Exemptions and Special Standards. The standards zn this reso~ution are intended to apply to the consCruc~ion, and des~rucCion of wells througi~out the County of Butteo However, under certain circumstances, proeection of ground water quality and/or a specific we1~ may require more seringene seandards; under other circumstances, it may be necessary to deviate from these standards and substitute other measures which will provide protection equal to fhese standards. If the Health Officer finds that compliance with eny of the requirements prescribed herein is impxaceica~ for a particular location because of unusuaJ. conditions and would resul~ in consCruceion of an vnsatisfactory weltl,'`he-`fn~y prescribe alternative requiraments equal to tYcese standards in terms of protection obtainedo In locations where existing geologic and/or ground waker conditions require standards more restrictive than those contained herein, or in addition eo them, the Health Officer may requixe such ` ` speciaL seandards. Section II, Well location. A) All water wells sha7.7. be located an adequate horizontal distance from potential sources of contamination and pollueion and sha11 conform to the ~01.7.owi.ng minimum horizontal separation distance in Tab1e I. Resolution 77-124 TABLE I Minimum Horizontal Separation llistances of Wells from Sources of Sewage Contamination Type of Well Faciliey Commnuitv Other Septic Tanlc, Sewer or Privy 100' 50' Sewage Leach Fie1d 100' 100'~' Cesspool or Seepage Pit Z50' 150' B) Where alternative locations are avai7.able, wells sha11 be ins~ailed up ~he ground water gradient fram sources of contamination. C) Following are requirements to be observed in locating drainage wrells: la N~ drainage ~,eii shall be installed c3.oser than: ao 200' to anq watier well. b, 100' to any septic tiank disposai fieZd. c, 150' to any septic tank seepage pit. d, 5U' to any septic Lanka 2o Within the Chico Urban Area, as defined in the Butte County Subdivision Ordi.nance, no drainage well sha1Z extend deeper than the lst gravel strat~ encountered and s11a11 in. no case extend to a depeh greater than 50'. In areas where this resolution does not specify maximum depth, maximt~m permitted depth shall be specified by the Health Officer, Because o£ differing geological and sub-surface hydrological conditions in Che County of Sutte, the Board of Supervisors may from time to time set forth additional requirements Pox drainage we11s for the purpose nf proCeceing underground waters. Section III. Seali.ng the Uppe:r Annular Spaceo The space between the we1~ casa.ng and the wall of the dril3.ed hole (ehe annular space) sha11 be effectively sealed to protect against contamination or pollution by surface and/or shallow, sub-surface waters as se~ forth below, * Where the parceZ on which the we11 is to be located was created before Apri1 4, 1974~ a.f such wells cannot be installed 100' from a leach field, they shall be instaYled as far as possible from leachfields but in no case less than 50'0 -2- Resalution 77-124 A) DepCh of Seal. Following is the minimu~ depth ot seal below ground surface for various uses of wells: Type Depth of Seal (beiow<:Qround sur#ace) Community Water Supply Wells 50 feet Individual Domestic We1Zs 20 feet ~/ B) Sealing Conditions. Following are requirements to be observed in sealing the annular space: lo Wells that are fully situated or at considexable depth in unconsolxdaeed, caving materiaZa a. Wliere the cable tool method o£ drillzng is used and a conducCOr casing is installed a~d left in,place,the annular space between Che inner casing and conductor casing sha11 be fil~ed with sealing maCeriaio bo Where the rotaxy method of construction is used, the annular space shall be filled with sealing material to the depth specified in Part A of this section. When a temporary conductor casing is used to hold out the caving material during placement of Che seal, it may be left in place or withdrawn+as the sealing material is placed. 2. WeZls that penetrate skratified formaeions. If an impervious (consolidated) formation is encountered within 5 feet of where the bottom of ~he seal described in Part A of this section should terminate, fihe seal shall be extended into the impervzous formation. 3e Gravel packed wells. In we11s constructed without a conductor casing, tihe gravel paek shaxl terminate at the base of the seal. Gravei fill pipes may be installed in tfie seal. Zn wells constructed with a conductor casing (which allows the.gravel pack to 1/ Exceptions are shallow!wells where the water to be developed is at a depth less than 20;£eet. In this instance, the depfih of seal ~ay be reduced but in no case less than 10 feeti and special precautions shall be taken in locating the well with respect to possibxe sources of contamination. -3- Resolution 77-12~ extend to the top of the well), the annular space between the conductor casing and the wall of the dxiXXed hole shall be sealed to ~he depth specified in this section. 4. We11s that are fully situated in consolidaeed rock, (Open bottom weZ1s). An over-s~zed hole must be conseructed to the depth and diametier requfred for,the seal and casing installed to retain the seala C) Conducror CasinQ. For public water supply wells, the minimum thickness of steel conductor casing sha11 be 1/4 inch for single casing or a minimum of No. 10 U.S. Standard Gage for double casing. D) Sealing Material. The sealing material shall consist~ of neat cement, cement grout, puddZed clay, or concrete. The neat cement mixture sha11 be composed of one bag of PortZand Cement (9~ pounds) to 3 to 7 gallons of clean water. Cement grout shall be composed of not more than two par~s by weight of sand and one part of cement (per bag of cement) eo 5 to 7 gallons of clean watere Quick-setting cement, retardents to setting, and other addxt~ves including hydrated lime to make Che mix more fluid (up to 10 percent of the volume of cement), and bentonite (up to 5 percent) to make the mix more fluid and to reduce shxinkage, may be used, Concrete used sha11 be "C1ass A" (6 sacks of Portland Cement per cubic yard) or "Class B" (5 sacks per cubic yard). E) Thickness of Sea~. The thinkness of the seal shall be at least two (2) inches, and not iess than three (3) times the size o£ the largest coarse aggregate used in the sealing materialo F) Placement of Seal. The sealing maCerial shall be applied, if possible, in one continuo~s operation from the bottom of the znterval to be sealed ~o the top. The sea~ing material for a public water supply well sha11 be placed through a pipe extending Co the bottom of the interval to be sealedo The pipe may be raised as the annu~ar space fi11s with sealing material. For other we11s, the sealing material may be installed by introducing it into ehe top of tihe annular space providing that the annular space does noe exCend into the water table and is drq. The sealing material shall be of such consistency and shall be introduced -4- Resolution 77-124 in a manner to prevent bridginga In any circumstances where the annu~ar space extends into a water table, the sealing materiaZ shall be introduced as for publ~c water supply we11s. Section TV. Surface Construction Features. A) The casing sha11 extend not less than 12" above the surrounding ground surface and not less than 2" above a concrete well house floor or concrete platform required zn the fol~owing section. B) A monolithically pnured concrete platfo~m sha11 be constructed around the top of the well on thoroughly compacted earth, whether the pump is mounted over the well, offset, or is a submersible type. Said platform shall extend outward not less than 12" compleCely around the casing and shall not be less than 4" Chick. C) Surface ConstYUCtion Features. 1. Openings. Openings into the ~op of the well which are not constructed to provide access to the well sha11 be sealed. Openings designed to provide access into wel~ cas~ngs for making measurements, adding gravel, etc., shall be prorectied against entrance o£ surface waters by installation of sanitary caps, plugs, screens, or downturned "U" bends. a. Where the p,.map is installed direct].y over the casa.ng, an annular sanitary seal shall be placed between the pump head and the p~p base (slab), or a sanitary seal shall be p7.aced between the pump base and the rim of the casing, or a seal or "well cap" sha11 be i.nstalled to close ehe annular opening between the casing and th.e pump colimui pipeo b. Where ehe pump is offset from the well or where a submersible pump is used, the opening between the well casing and any pipes or cables which enter t~e we1J. shall be closed by a sanitary seal. or "well cap". c< All holes in the base of the pump whicte open into the well shall be sealed. d. If the pump is not installed immediaCely upon completion of the well, ox i£ there is a prolonged interruption in construction of the we7.1, a saniCary cap sha11 be pxovi.ded at the ~op of the casing. - 5- Resolut£on 77-I24 e. Pump discharge piping shall be located above the ground whexe possible; however, in the event of a below-ground dischaxge (below pump base), there sha11 ba a sanitary seal or gasket betwaen the discharge pipe and we11 casing. fa Where the well is to be gravel packed, a watertight cover shall be installed between the conductor pipe and the inner° casing (if a conduct or pipe is used) or between the casing and the wa11 of the drilled hole at the top of the we11o 2o Enclosure of Well and Appurtenances. For public water supply wells, the well and pump shall be Iocated in a locked enclosure to exclude access by unauthorized persons. 3. Pump Blowoff. When there is any blowoff or drain line from ~he pump discharge, it shall be so Iocated that there is no hazard to the sa£ety of the water supply by reason o£ flooding, back siphonage, or back pressureo The blowoff or drain line shall not be connected to any sewer. 4. We11 Pits. a. The use of wel~ pits for pub~zc water supply we11s is prohibited. b. Yf a we11 pit is used for other types o~ wells, the following conditions sha11 apply: (1) The bottom o£ t~e pit shall not extend below ehe water table. (2) The git and pit £Ioor shall be constructed of concrete or similar material 3n such a manner that rain, flood, or seepage waters cannot enter it. (3) The casing shaZl extend not less than 6" above the pi~ £loor. (4) Unless the well is equipped wieh a submersible p~p, the pit sha11 be provided with a drainab~e s~p and an automatic sump pump, or of topography pexma.ts, a gravity sump draine The discharge pipe from the stmmp shall not be connected tio any sewer or pipe dxain. The outlet of the discharge pipe S~a1i no~ be below ground level, shall -6- Resolution 77-124 be above known conditions of flood~ng and protected against entry of smail animals and vermino (5) The ~op of the pit shal7. be provided with a sanitary cover such as a concreCe slab, metal cover, or hous9.ng of equivalent construction adequate to prohibit rain water, anima~.s and vermin from gaining access eo Che pit. (6) Each pit shall have easy access £ox pxoper maintenance, operation, and inspection of equipment and sha11 have a locked door or haCch as necessary to insure public saEety. Section D. Disinfection and other Sanitarv Requirementsa A) Disinfectiono All co~unity water supply and individual domestic wells sha11 be disinfected following construction or repair before the well is placed in serviceo S) Gravel. Gravel used in gravel-packed wells sh.a11 come from clean sources and, except for agricultura2 wells, should be thorough~.y washed before being placed in the well.e Gravel purchased from a supplier should be washed at the pit or plant prior to delivery to the well site. C) Lubricantso Mud and water used as a drilling lubricant shali be '~ree from sewage contamination. Oil and water used for lubrica- ti.on of the pump and pump bearing sha~.l a3.so be free from contamination. Sectian ~1I. Casine. A) Galvanized sheet metal pipe ("downspout") or natural wood shall not be used as casing: B) InsCaliaCion of Casing. All casing shall be placed with su£ficient care to avoid da~age to casing sections and join~so Where casing is driven (as is generally the case wizen the cable tool method of construction is used) the casing shall be equipped with a drive shoe at the lower ende All joints in the casing above perforations or screens sha17. be watextighte The uppexmast per~oxations sha1.7. be at least below the depth specified in Section II, Part A, "Depth of Seal". ..~_ Resolution 77-124 Section VIZ. Water Qualitv Samplin~. The requirements to be followed wfth respect to water quaiity sampling are: A) Communit Water Su X WeX1so The water trom a~~ community water supply we11s shall be sampled i~mediately following development and disinfection, and appropriate analysis sha11 be made. Approval of the enforcing agency must be obtained before ehe we11 is put into use. 1, Sample tap. Excepe where ehere is free dfscharge ~xam the pump (that is~ there ~s no direct connectxon to the water delivery system} a sample`tap shall be provided on this d~scharge line so that water representative of the water in the we11 may be drawn for Iaboratory analysis. 2. Laboratory Analyszso The appropriate analysis sha11 be pet~ormed by a laboratory certified by the California Department of Public Health, A copy of the laboratory analysis shall be forwarded to the CaliEornia Aepaxtment of Public Hea~kh or to the 1oca1 Health Department. 3. Bacterial Quality. Samples sha11 be collected for bacteriologicaZ analysis (presence of coliform organism) after all traces of development and disinfectant chemicals have been removed from the welio Section VIII. Snecial Provisions £or Zar~e biameter Shallow Wellso A) Use as a Co~unity Water Suvply Wells. The use of bored ox dug welis, or wells less than 50 feet deep, to provfde communiey water suppiies sha11 be avoided unless ~here is no other feasible means ~or obtaining water. Wtren used for ~his purpose, these wel~s shall be located at ~east 250 feet from any underground sewage disposal facility. B) Sored Wells. A11 bored wells shall be cased with concrete pxpe or steel casing whose joints are watertight from 6 inches above surface to the depths specified in Seceion ZZ, Part A. The space between the wa~l of the hole and the casing shall be filled with concrete to the depths specified in Section II, Part A. The minzmum thickness of the surrounding cancrete seal shall be 3 inchese C) Du~ WeZ3.so All dug wells shall be "curbed" with a watertzght curbing extend~ng from the surface to the depths speci£ied in Section II, -8- Resolution 77-124 Part A. The curbing shali be of poured-in-place casing (eithez precast concrete pipe or steel) surrounded on the outside by concretea If the curbing is to be made of concrete, pouxed-in-place, it shall not be less than six inches thick. If precast concrete pipe or steel casing is used as part of the curbing, the space beCween the wa~Z of khe hole and the casing shall be filled mith concrete to the depths specified in Section II~ Part A. The minimum thickness of the surrounding concrete shall be four inches. A) Covers. A11 bored and dug wells shall be provided with a structurally sou~d sanxtary cover made of concrete or steel. Section IX. Snecial Provisions for Driven Wellso A) If the we11 is to be usad as an individual domestic well, an oversize hole with a diameter at least ehree inches greater than the diameter o~ the p~pe shall be constructed to a dep~h of six foot and the annnlar space around the pipe shail be filled with neat cement, cement grout, or a bentonite mud. Section X. Temporary Cover. Whenever there is an interruption in work on the we11 including but not Iimited to overnight shutdown, far inclement weather, for waiting perfods xequ~red for the setting up on sealing materials, for tests, or fox insta~Iation of the pump, the well opening shall be closed with a cover to prevent the introduction nf undesirable material into the we~~ and to xnsure the public safetyo During interruptions of one week or more~ a semi-per~nanent cover sha11 be znstalled. .For we~Is cased with steel, a steei:icovex, eack-welded to the top o~ the casing, is adequate. Section XI. Destruction of Abandoned We11s. A) General Requiremen~. All "abandoned" wells sha11 be destroyed in such a way that they will not produce water or act as a chaanel ~or the interchange of waters, when such=interchange will result in significant deterioration of the quality of water in any or aZl water- bearing formations penefrated, or present a hazard to the safety and we11 being o~ people and of animals. -9- Resolution 77-124 Destruction of a we11 sha11 consist of the complete fiZling of the we11 in accordance with the procedures described in Part B of this section. B} Reauirements for Aestrovin~ Wells. lo Objective. The objective of the xequirements described in this section is to restore as neaxly as possible those subsurface conditions which existed before the we1Z was constructed taking into account also changes, if any, which have occurred since the time of constructian. (For example, an aqui€er which may have produced gond quality wa~er ae one eime but which now produces water of inferior qualieq, such as a coastal aquifer that has been invaded by seawater)> 2. Preliminary Work. Before the hole is ~i~~ed, the we11 shall be investigated to defermine its condition, defiaiXs of canstructzon, and wheeher there are obstructions that wi11 interfere with the process of filling and sealing. , a. If there are any obstructions, they shall be removed, if possible, by cleaning out the hole or by redrilling. b. Where necessary, to insure that sealing material fi11s not only the well casing but also any annular space or nearby voids, the casing sha11 be per£orated or otherwise punc.~u~ed: ca In drilled wells, it may be necessary or desirahle to remove some of the casing. However, in some cases this can be done only as the we11 is filledo In dug wel~s, as much of the lining as possible should be removed prior to fillinga 3. Filling and Sealing Conditions. Following are requixements to be observed when certain conditions are encountered. a. Well wholly situated in unconsolidated material in an uncon£ined ground water zone. Tf the ground water supplfes axe within 50 £eet of the surface, rhe upper 20 feet sha11 be sealed with impervious material and the remainder of the well shall be filled with clay, sand, or other snitable inorganic matexialo -10- Resolution 77-124 b. Weil penetrating several aquifers or foxmationso In a11 cases the upper 20 feet of the we11 shall be sealed with impervious material. In areas where ~he interchange of water between aquifers will result in a significant deterioration of the quality of water in one or more aquifers, or w~ii result in a Zoss of artesian pressnxe, the we11 shall be filled and sealed so as to prevent such xnterchange. Sand or okher suitable inorganic material may be pZaced opposite the produc~ng aquifers (or formations) and othex formations where impervious sealing material is not requ~red. Impervious material must be placed opposite confining formations for a sufficient vertzcal distance (but in no case less than 10 feee) in either direction to prevent the vertical movement of water from the producing formationo The formation producing the deleterious water shall be sealed by placing impervious material opposite the formatiion, and opposite the confining formations for a sufficient vertiical distance (but no less than YO feet) in either direction, or, in the case of "bottom" waters, in tihe upward direction>~ In locaeions where interchange is in no waq detrimental, suitable inorganic material may be placed opposite the formations penetrated. When the boundaries of the various formations axe unknown, alternate layers of impervious and pervious material shall be placed in the well. ~ Deeermining the significance of interchange of waters whose qualities very and of the loss of artesian pres~ures, requires extensive knowledge of Che ground water basin in questiono The Department of Water Resources has over the years, and frequently in cooperation wfth agenc~es such as Che United States Geological Survey, undertaken a number of ground water seudies and amassed considerable information and data about the subjecto Alehough much is known about ~he State`s ground water supplies, detailed sCudies sufficiently accurate to define interchange problems have been made only in certain areas. In still other areas, there is only partial definition of the problem. Example of areas where definition has been made are the coastal plain of Los Angeles County, and the eastern part of the Santa C1axaValley in Alameda Countyo Recammendations for water Weii standards for these areas have been published by the Departmento (Alameda County, BuZletin No. 7~-2; Central, Hollywood, and Santa Monica Basins, Zos Angeles County, Bulletin Noo 74-~; and West Coast Basin, ~os Angeles County Bulletin No, 107). An excellenC example of a"bottom" water is ehe saline connate water underlying the Central Valley at varying depthso -11- Resolu~ion 77-124 c. Well penetrating creviced or fractured rock. If creviced or fractured rock formaeions are encountered just below ~he surface, the porCions of the well opposite this formation shall be sealed with neaC cement, cement grout, or concrete. If these formations extend to considerable depth, alterna~e layers of coarse stone~ and cement grout or concreCe may be used eo fill the well. Fine grained material shal~ noC be used as fill material for creviced or fractured rock formations. d. Well in noncreviced, consolidated formation. Tfie upper 20 £eee of a we11 in a noncreviced, consolidated formation sha11 be filled with impervious material. The remainder of the well may be filled wieh clay or other suitable inorganic material. ~o Well penetra[ing specific aquifers, local condztzons. Under certain loca~ conditions, the enforcing agency may require that speczfxc aquifers or formaeions be sealed off during destruction of the we11, 4o Placemenr of Material. The following requ£rements shall be observed in pYacing fill or sealing material in wells to be destroyed: a< The weil shail be filled with the appropriate material (as described in item E of this sectioa) ~rrnn the bottom of the well upe b. Where neat cement, cement grout~ or concrete is used, it sha11 be poured in one continuous opexation. • co Sealing materiai sha11 be placed in the interval or ineervals to be sealed by methods that prevent free fall, dilu~ion, and/or spearation of aggregates from cementing maeerials. d, Where the head (~ressure) producing flow is great, special care and special methods must be used to reserict the flow while placing the sea~ing materia~> In such cases, the casing must be perforated opposite the area to be sealed and the sealing material ~orced out under pressure into the surrounding formation. - ~ * The limiting dimensions of coarse stone are usually considered to range be~ween 1/4 and 3 inches. -12- Resolution 77-124 e. In destroying gravel-packed wells, the casing sha11 be perforated or othexwise punctured opposite the area to be sealeda The sealing material sha~1 then be placed within the casing, completely filling the portion adjacent to the area to be sealed and then forced out under pressuxe into the gravel envelopeo f< When pressure is applied to force sealfng materia~ into the annular space, the pressure shall be maintafned for a length of time sufficient for the cementing mixture to seto go To as~uxe tha~ the well is fil~ed and that there has been no jamming or "bridg~ng" o~ ~he matieriaZ, veri£ication shall be made that the volvme of ma~exial placed in the we11 installation at least equals the volume oP the emp~y hole, 5o Materials, Requirements £or sealing and £i11 materials are as follows: aa Impervious SeaZing Materials. No maeerial is completely impervious. However, sealing materials shall have such a 1ow pexcneability that the volume of water passing through them is af smal~ consequenceo Suztable materials include neat cement~ cement grout~ concrete~ bentonite clays (muds), silt and clays, weli proportioned mixes of silts~ sands~ and clays (or cement), and native soils and natural materzal that have a coefficient of permeabi~~ty o~ ~ess than 100 feet per year.* Used drz~I~ng muds are not acceptabie, A neat eement mixture shall be composed of one bag of Portland Cement to 5 to 7 ga~lons of clean water. Cement grout sha11 be composed of not more tham two parts of sand and one part of cement (per bag of cement) to 5 to 7 gallons of clean water, Concrete used shall be "Class A" (6 sacks of Portland Cement per cubic yard) or "Glass B" (5 sacks per cubic yard)o ~ ExampZes o~ mater~als of this type are: very fine sand with a Iarge percentage of silt or ciay, inorganic silts, mixtures of si1C and clay, and c1ay. Native materials should not be used when the sealing operatxon involves the use of pressure. -13- Resol~tion 77-124 b, Fill Material. Many materials are suitable for use as a filler in destroying wellso These include c1ay, silt, sand, gravel, crushed stone, naCive soils, mixtures of the aforementioned types, and those described in Che preceding paragraph. Material containing organic matter shall not be used. 6. Additional Requirements for Wells in Urban Areas. Tn £ncorporated areas or unincorporated areas developed for multiple habifiation, to make further use of the we11 site, the following additzona~ requirements must be met: a. A hole shall be excavated around the we11 casing to a depth of three feet below the ground surface and the we11 casing removed to within six inches of the bottom of the excavatxon, b, xhe sealing matexial used for the upper portion of the well shall be aliowed to spi11 over into the excavation to form a cap at least one foot thicke c. After the we11 has been properly filed, including sufficient time for sealing material in the excavatfon to set, the excavation shall be filled with native soile 7. Temporary Covero During periods when no work is being done on the well, such as overnight or while waiting for sealing material to set, the well and s~~ excavation, if any, sha11 be covered. The cover shall be suf~iciently stzong and well enough anchored to prevent the introduction o£ foreign materiaZ into the well and to protect the public £rom a potentia~Xy hazardous situatxon. 5ection XI. ~ermit ApplicaCion ~ees. The following penuit application fees for permits issued pursuant to Chapter 23 B of ehe Butte County Code shall be as follows: 1. Construction of new wellso .... a. e$20 2o Destruction of abandoned wells. o 0 0..No Fee 3. Construction of drainage we11s. o o e e$15 -14T Resolution 77-124 PASSED AND ADOPTED by the Butte County Board of Supervisors on this 26th day of July, 1977, bq the foilowing vote: AYES: Supervisors Lemke, Madigan, Moseley, Winston and Chair¢tan Richter NOES: None ABSENT: None NOT VOTINGo None i~oG=-,i ~ ~~ ~ BERNARD D. RICHTER, Chairman Butte County Board o€ 5upexvisors AT~ES~: CLARK A. NELSON~,COUNTY CLERK and ex-officzo Clerk of the Butte County Board of Supervisors By ~G.~!.k-c/~ ~ .~`'~P.-~'zv~+-. -15-