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Home My WebLink AboutOWTS DesignGCI ENcTNEERT{c .l/l3zl -1¿¿.f,roard G¡¡nd Juncllon, GO 81505Gtottk Consttactlon lnc, Grand Junction (970)6/rO-5V29 . Glenwood SpringslAspei (970) ó40-5029 . Montrose/Delta (970) 64ù5029 Emait ccigi@msn-com. ONSTTE WASTEIVATER TREATMENT SYSTEM DESIGN Date:October 28,2021 Prepared by:Thomas A. Cronk, P.E- Cronk Construction Inc" l13l -24-Road Grand Junctiot¡ CO 81505 970-640-5029 Type of Design: NewResidential Client:JohnPlacek PO Box 455 silr, co 81652 970-379-1096 crystalconst@sopris.net Property Address -TBD- Scutter Lane, Rifle, CO 81650 TanscheduleNo.: 212-72-84-00-388 LegalDescript.: I 1.0 Site History The site consisg of approximately 35.8 acrcs of uncultivated native soil. Drainage is approximately lW/o to the south-east. A percolation test/soils evaluation was conducted on the property ofreference on rcnUn by Tom A. Cronk, registered professional engineer (RP.E.). The perc excavation trench was located approximately 690'south of the north properly line and approximately 180' east of the west propefy line. The owner of the properly wishes to consfuct a three bedroom residence at the site. An onsite wastewater treaûnent system (OWTS) sizod for the three bedroom loading is proposed to treat serilage waste generaf€d by the project. An OWTS design has been prepared for the project based on information disclosed during the 10/221'21 site investigations. A discussion of the engineered OWTS design follows. Tlß lùnzl2lperc tesfsoils evaluation is attached for reference as Appendix A. The site plan and locations of the l0l22l2l soils excavations are shown on the attached plot plan. 2.0 Develonment of Design Parameters Tlrc perc excavation trench was extended to a depth of 108" below ground surface (BCS). There was no evidence of ground water or high seasonal water table in the open excavation to a depth of 108" BGS. The soils evaluation indicatps thres distinct soil horizons underlie the site. A lithologioal description follows: denth (in.) descrintion o" -24 silty clay, light pinkish tan; blocky (USDA - silt loam, blocþ, weak structure) sandy clay, light red; blocþ (USDA - sandy loam, blocky, weak structure) siþ cla¡ red; harcl and smeared (USDA - siþ clay, plary; strong structure) 24" -60" Based on the results from the lÙl22l2l (Appendix A), r design perc rate of 39 min/in. and corresponding long term acceptance rate (LTAR) of 0.50 arc chosen for overall system sizing for an infiltr¿tor trench absorption field designed to discharge to subsoils below the 48" depth- 60" - 108" 2 3.0 Svstem Desigqr An INFILTRAÍOR absorption trench is proposed for discharge of septic effluent at the site. Construction of the systom will consist of excavating level trenches in the area comprising the absorption ñeld. As shown in the attached septic layout plan, the trenches will be oriented perpendicular to the natural slope to minimize the depth of excavation along the french lengfh. Each ûench excavation shall be continued to a maximum depth of 48" BGS atthe uphill side of the trench (see absorption field cross-section). After removal of surface soils, the open excavations will be disked or scarified to promote subst¡rface absorption. Following completion of the initial push-outs, QUICK4 STÅNDARD INFILTRATORSwiII be used to consfuct a septic effluent distribution sysûem in the open excavations. Tlie INFILTRAIOT\ effluent distribution system will be installed in accordance with the "Infiltrator Technical Manual", available from Infiltrator Systems lnc.,l23 Elm Street Suite 12, Old Saybrooþ Connæticut O&75- Adjacent INFILTRATORS shall be fastened with a drinimum of four (4) 3l4 x #8 self-tapping sheet metal or bright brass deck scr€rilsto prevent movement and separalion during backfilling. Septic effluent will be transfened from the upper french to each of the adjacent downhill trenches tfuough a serial dishibution network as shown in the attached constuction details. The serial disfibution connections between adjacent trenches will facilitate the saturation of the uphill üench before septic effluent is allowed ûo flow to each ofthe adjacent downhill trenches. As shown in the attached Absorption Field Cmss Section, the botfom of the STANDARD INFILlnlTORseepage henches will be located amaximum of48" below ground level. Aftßr the INFILTRATORS are installe{ synthetic filter fabric (140-200 mesh) will be placed over the trenches and the systêm will be cove¡ed with a soil cap. The soil cap will consist of approximaûely 36" oî native soil backfill. The soil cap will be mounded 5o/o above the existing ground surface to promoûe surface run offaway from lhe absorption field. The inst¿ller should confirm the feasibility of gravity discharge of sewage effluent from the structure to the absorption field by field verification of assumed desþ parameters. Assumed design parameters with respect to gavity discharge include: distance from the sewage pipe at exit from the foundation line to the absorption field 70'or less, elevation of the ground surface at entry to the absorption field shall be no more than2z" above the invert elevation of the sewage pipe af exit from the foundation line. If field m€asurements do not confirm these design assumptions , gnvity discharge of septic effluent ftom the proposed structure cannot be assured and a lift station may be required. Please cont¿ct the design engineer and Ga¡{ield County to address any design modifications necÊssaÐ/ if these design assumptions are rþt upheld. The installer must also confirm the setbacks from property lines, building envelopes, and existing easements shoç,n in the attached graphics are maintained. Four inch clean outs shall be provided at maximum 100' inûervals in all effluent lines exceeding 100' in lengh. Vehicle trafüc and pa*ing is to be prevented over the absorption and repair area. Provide minimum schedule 40 PVC under all tr¿ffic areas. a o 3 Additionall¡ effluent piping in traffic areas with less than 36" of cover shall be encased in 6" CMP or flow fill and covered with minimum 2u high density blue board insulation. Finally, any unknown utilþ lines, easementso or other adverse conditions disolosed during construction must maintain the required setbacks listed on page 5 of this document. Sewer lines or domestic water lines shall be encased in minimum SCHD 40 with waúer-tight end caps at all points with less than 5' separation between sewer and domestic water lines. A 1,000 gallon, two compartment septic tank nill be used to provide a minimum of 48 hours retention time for sewage generated by the propos€d three bedroom design- Septic tank access manholes must be extended to the ground surface. As discussed abve,INFILTRATOR absorption trenches are proposed to discharge septic effluent to the underlying suþsoils. As shown in the attached graphics, the absorption trenches will consist of three (3) trenches 3'wide x 48" deep x 72' longwith eighteen (18) STANDAW INFILTR{TOR(oI quivalørt) units eæh for a total of fiffy four (54) units. The absorption field will encompass an effective area of 925.71q.fr.. Calculations and design parameters used ûo size the absorption field follow. DESIGN CALCULATIONS DESIGN LOADING RATE OF 3 BEDROOMS @ 150 GAL./BEDROOM-DAY = 450 gal./day DESIGN PERCOLATON RATE = 39 MIN./INCH DESIGN LONG ïERM ACCEFTANCE RATE (LTAR) = 0.50 GAL./DAY-SQ. FT A: h,wHERE, A: ABSORPfiON FIELD AREA (SQ. FT.) Q- DESIGN FLOW (GAL./DAÐ LTAR: LONG TERM ACCEPTANCE RATE (GAL./DAY-SQ. FT.) A=#= 9oo ABSORPTION FIELD AREA ADruSTMENT FACTOR FOR GRAVITY TRENCH DESTGN: 1.0 ABSORPTION FIELD AREA ADruSTMENT FACTOR FOR USE OF CHAMBERS =.0.7 ADruSTED ABSORPTION FIELD AREA:900 X 1.0 X 0.7:630 SQ. FT. usE 54 QUICK4 STANDARD INFILTRATORS CONFTGTJRED rN SERTAL DTSTRTBUTTON ABSORPTION FIELD SIZED AT THREE TRENCHES 3FT. X 72FT = 648 SQ. FT. 4 4.0 Site Specific Inst¿[ation/Oneration Reouirements The owner and system contractor shall be aware and comply with the following installation and system operation requirements. 4.1 Installation - Setbacks. Notifications. and Inspections The system contractor must be approved and licensed by Garfield County for installation of onsite wastewater treaûnent systems. All installation activities shall be conducted in accordance with current Garfield County 0775 Reg"a/ariozs. If at any time during construçtion-subsurface site conditions are encountered which differ from_the design parameters developed in Sggtion 2.0. construction activities will sûop and the desierr engineer and Garfield County will be contacted to address anv necessary design Utodifications. Installation procedures including gradg location, setbacks, septic tank size, and absorption field size shall conform with the attached graphic details. Consfuction activities and system components will not encroach upon existing easements or utility corridors. A minimum of 5 ft of undisturbed soil shall be maintained between individual absorption elements and the septic tank. A minimum of4' of undisturbed soil shall be maintained betwæn adjacent absorption elements. Minimum site spocific setbacks for system components are: a a a a Source domestic wafer line domestic well domestic water cistern prope4y lines structure dcrawl space strucfure wo/crawl space irrigation ditch open intermittent irrigæion gat€d solid pipe/lined subsurface drain Septic Tank l0' 50' 50' l0' 5' 5' 50' l0' l0' l0' l0' Absomtion Field Buildine Sewer l0'25', 100' t00' l0' 20' l0' 50' 25', 25'. l0' 2''. To avoid surface flow infiltration and saturation of the new absorption system, abandonment of irrigation in the vicinity of the disposal system is required. Diversion ditchcs nec€ssary to divert surface flows around the new absorption bed must maintain the minimum setbacks listed above. All gravity flow sewer lines and eflluent dishibution piping shall be 4 inchæ in diameterand have gluedjoints. All lines discharging sewage from the residence to the septic ank shall maintain fall of between 1/8 in. and ll4 in.pæ foot and shall employ sweep 90's or 245's at all turns. Sewer lines from the dwelling to the septic tank and at least ó ft from the septic tank outlet must meet minimum standard ASTM-3034. Sewer lines under driveways shall always meet minimum Schedule 40 PVC standards. Additionally, effluent piping in traffic areas with less than 36" of cover shall be encased in 6" CMP or flow fill and covered wifh 5 a minimum 2" high density blue board insulation. Sewer lines or domestic water lines shall be encased in minimum SCHD 40 with water-tight end caps or a minimum of 6no of flow fill at all points with less than 5' separation between sewerand domestic water lines. A minimum of 12" of soil cover (18" recommended) shall be maintained over all gavtty draining ISDS components to pr€vent fræzingof septic effluent (excepting sepic tank acc€ss ports which must be extended to the ground surface). The installer shall not place the Infiltrators in the open excavation until inspected and approved by the design engineer. Additionally, the final cover shall not be placed on sewer lines, septic tanh orthe absorption area until the system has been inspected and approved by the design engineer and Garfield County. The installer shall provide 48 hour notice for all required inspections. Four inch clean outs shall be insølled at maximum 100' intervals in all gravity flow effluont lines exceeding 100'in length. The effluent disfübution system shall be constructed in accordance with the "lnfilfrator Technical Manual" available from Infiltnator Sysûems Inc., I23 Elm Sfrect, Suite 12, Old Saybrook, Connecticut 06475. Adjace,nt absorption field trenches shall be connected by a serial distribution system to assure saturation of the upgradient trench before effluent is passed úo the adjacent downgnadient trench (see attached absorption field plan view and cross section details). The IMILTRATORS will be covered with synthetic filter fabric (14G200 mesh) and covered with a surface cap. The surface cap shall be mounded 5olo over the absorption field. The system contractor shatt be aware of the potential for construction activities to reduce soil permeabilities at the siûe through compaction, smearing; and shearing. The following precautions and construction procedures should be employed during installation to minimize disturbance to native soils: i. Excavation should proceed only when the moisture content ofthe soil is below the plastic limit. If a sample of soil forms a rope instead of crumbling when rolled between the hands it is too wet and should be allowed to dry before excavation continues, ¡i. Excavation and backfill equipment should work from the surface where at all practical to avoid compaction ofthe soils at depth. ¡ii. The bottom and sidewalls of the excavation should be left with a rouglt, opøt surface. The appearance should be thât of broken or ripped soil as opposed to a sheared, smeared, or foweled surface. Any smoothed or smea¡ed surfaces should be rernoved with a toothed rake or shallow ripper taking cme to remove loose residues from the bottom of the excavation by hand if necessary' iv. Care should be taken in placing fill materials in the excavation to ¿void damaging the exposed soil surfaces. a a a a a a 6 4.2 Operation - Maintenance and Inspections The owner shall install a structural banier if necessary and take precautions to prevent vehicular traffic, excessive surface watering accidental flooding or other activities in the vicinity of the absorption field which may compacÇ saturate, or otherwise alterthe subsurface soil parametem used in desigring the septic system. The owner will plant and maintain grass or other shallow rooted cover crop to prevent erosion and promote evapoûnanspiration over the absorption field- The ownerwill inspect and maintain the required mounding and drainage away from the absorption field to prevent saturation from pnecipitation and surface flows. To mitigate the generatíon of preferential flow channels which may compromise the operation of the system, the ovmer will inspect and prcvent intmsion of burrowing animals and deep root€d plants into the absorption field. The septic effluent filter sh¿ll be inspected and cleaned as nocessary every six (6) months. a a o a a a The owner will conduct periodic maintenance of the septic system by removing accumulated sludge f¡om tho septic tank every 3-4 years to prevent clogging ofthe absorption field. 7 5.0 Limitations This report is a site specific design for installation of an onsite wastewater treaûnent sysûem and is applicable only for the client for whom our work was performed. Use of this report under other circumstances is not an appropriate applicafion of this document. This report is a pnrduct of CCI Engineering/Cronk Construction Incorporated and is to be úrken in its entirety. Excerpts from this report may be taken out of context and may not convey the true intent of the report. It is the ownet's and ownefs agent's responsibility to read this report and become familiar with the recommendatíons and desigrt guidelines contained herein. The recommendafions and desþ guidelines outlined in this report are based on: l) the proposed site development and plot plan as furnished to CCI Engineering/Cronk Construction lncorporated by the clien{ and 2) the site conditions disclosed at the specific time of the site investigation of reference. CCI Engineering/Cronk Construction Incorporated assumes no liability for the accuracy or completeness of ínformatíon fumished by the client. Site conditions are subject to exfernal environmental effects and may change over time. Use ofthis plan under differe,nt site conditions is inappropriate. If it becomes apparmt that current site conditions vary from those anticipated, the design engíneor and Garfield County should be contacted to develop any required design modifications. CCI Engineering/Cronk Construction Incorporated is not rcsponsible and accepts no liability for any variation in assumed design parameters. CCI Engineering/Cronk Construction Incorporated represents this report has been prepared within the limits prescribed by the owner and in accordance with the current accepted practic€ of the civil engineering profession in the area. No warranty or representation either expressed or implied is included or intended in this report or in any ofour contracts. 3fr% Thomas A. Cronk, P.E. Date sewage dÍsposal plan is meant ûo include the following four ¡rages of graphics Íncluding: l) plot plan,2) septic layout plrrn,3) absorption field plan viem' and 4) absorption field cross scction. The plan is not to be implemented in the ab¡ence of these releted graphics. In addition, resulß from the percolrtion ûest and soils evaluat¡on ane included for reference as Appendix A. 8 I {þItn¡ Izotirt rll Hl¿l 1¡,ðÞ ooz. Ût4q)(''e \ I I --}-l ?0' prlvote dFlve & occess eoseqgnt -t e0'prlvate drlve & ?nergency occess eqsenent l0'prlvote drlve & energeñcy occeSs eqseneït 35.79 cc¡es rll¡ Ìr \\stUìt r;lo'IJlllñI rÈ \\'l¡ {r l 1 ¡Dår¡ toq \zoq(tq n'@ tzt?4' opproxlnote tocotlon of rett 317.36'Nç'o.æ'E I \aì/f /h' PLACEK PROJECT -TB¡¡- SCUTTER LANE ele-7?-84-00-388 PI-I]T PLÁN IETOEER æ,4"1 SCAI-E¡ r'=e00'NfTRTH NIITECONTRACTI]R TI] VERTFY SLEPE,IASSBRPTION FTELII IIRIENTATII]NTB BE ADJUSTEI' PER SITEVARIAÎ¡BNS TIl FACIL¡TATECENSISTENT TRENCI{ DËPTH,RUNNING PARALLEL ÎD NATURALCONTEURSNOrECALL 811 FOR UTILITY LBCAÎES35,79 qcresout---w.----\-t-t.cEI1000ù.,TJh€tonkolosorptloh fletdoç 3 rors of 18 Oulck4stondârd InflltFôtoFs (ordlstnlbutlon os shotnequlvotent) for o totot of54 unlts conflgured ln serlof(usI\-¿o.\î.ony't\ee.III\PREJECTSCUTTER LAÌ.IENIRTHT3D-LAYSUT PLAN1'=¡[0'e8. 4021NI]TETHE FELLOVING SETBACKS I,IIUST BE }.IAINTAINEDISEPÎ¡C ASSTIRPTTI¡NTANI( FÎFI NSPRINGS/VELLS -50'LAKE/STREAM/IRRIG, I¡ITCH - 50'INTERMITÎENT IRRIG. DITCH- 1O'6ATEr! PIPE -10.SOLI! PIPE/LINED D¡TCH -10'DIIMESTIC VATER CISTERN _50.Dor.tEsTIc VATER LINE _ t0.STRUCTURE V./CRAVLSPACE - s'¿STRUCTURE VB/CRAVLSPACE_ 5,PRITPERTY LINE -10'100'50,¿5',a<,10,100'e5'?o,10'10'pnoposedresldenceNETEGRAVITY DISCHARGE OF SEVAGEEFFLUENT FRBII THE RESIIIENCETO THE D¡SPI¡SAL SYSTEM ISBASED EN THE FBLLI]h'ING DES¡6NASSUMPTTENSTLENGTH IIF SEVAGE PIPINGFROM EXIT AT FI]I,JNDATIBNL¡NE TB ENTRY TI¡ ABSI¡RPTITINFIELD = 70'ER LESSELEVATIÍ¡N f]F 6RIIUN! SURFACEAT ENTRY TE ABSIRPTIBN FIELD- Ntl l{ERË THAN ee' A30VE¡NVERT ELEV. OF SEVAGE P¡PEAT EXIT FRO},I FBUNDATIEN LINEItlSCLAlt¡tERIF THESE DES¡GN ASSIJI,IPT¡ONS ARENT]T UPHELI! I¡URING CBNSTRUCTIBN,GRAVITY D¡SCHARGE CAN NIIT 3EASSURED AND A LIFT STAT¡ON }IAY9E REOUIREDnolntqln approprhte setbockif¡on 0!lTS conponents ond rel( *2*3*1dlstrlþutlonr¡ln,qt eqch eñd oftnench3/1 (332) stopecrp, P¡ovlde5Z dnolnogefItentyp,deslgned to ossure sotr,¡¡otlonof upgradlcnt trerch beforeefftuent ls oltored to overflorto odJocent doungnodlent trenchexlstlhg gnound surfaceIdsk or scqrlfyeoch lnflttrqtor trehch\ln occordonca36'--t/--¿/-?4'-60,-108'SN¡LS LI]G(SEE NETES)\olr,IIII/4'nln.C0'-t?' preferred)'LACEK PRI]JECT-TBÐ- SCUTTER LANE?t2-7?-84-00-388ABSIRPITON FIELD - CRIISS SECTTON]CTBBER 28, ?O?ISÛALET l'=5'\GIJICK4 Il,lFILTRglER, lnsto,tt\WITh,INFILTRATOR TECHNICAL MANUAL"qvolìoble fron Inflttrotor Sys+elìsInc,, 1?3 Et¡¡ Straet, Sulte 1?, BtdSaybnook, Connectlcut 06¡175 \ __Ityplcot lnflttrotor trenchcrÕss sectlon (onå of thnee)ABSERPTIITN FIELD - CRI¡SS SECTION (TYP. TI.IREE EF THREE)ELEVATIIIN DES¡GN SPECIFICATII¡NSINVERTAT EXIT FRB,I FEUNDASETLS LOG NETES*l - SILTY CLAY, LIGHT PINK¡SH TANI BL0CKY(USIIA-SILT LTAM, ILI]CKY, VEAK STRUCTURE)åE - SANDY CLAY, LI6HT RE!¡ BLOCKY(USDA-SANIIY LOAII, BLI¡CKY, VEAK STRUCTURE)*3 - CLAY, RED¡ HARD AND SIIEARED(USDA.SILTY CLAY, PLâTY, STRI¡N6)NO EVIDENCE I¡F GROUNDVATER OR HIGH SEASENAL VATER TAILE TOA DEPTH I]F 9?' BELOV GROUND SURFACE (BGS) septlc lñftuent s€rtot dlstrlloutlon conflgl¡rstlon, olt€rnote end-to-end, typ. provlde lnspectlon/ventlhg ports ot eoch end of lnflltrator trenches o's shotn ABSÍ]RPTIIIN FIELII - PLAN VIEV SCALE¡ l'=?0' three (3) rors of elghteen (tg) OUICK4 STANIIARII INFILTRAT0R unlts foa o totot of fl€ty foun (54) uhlts conflgured ln s€rlot dlstrbutlon ô5 shotn I ls ¡: t- I 4' SCIO ¡0fl PVC VE{T/INSPECIIIII{ PORT sfttL câP SERIAL IIISTRIBUTION INLET - USE HIGH KNÍ¡CKOUT, (ENI} ffi SIII€) SERIAL IIISTRIBUÏII¡N OUTLET - USE HIGH Kil(]cKfruT (END In SERIAL Dl TRßUilON SCAI.E: co¡{NEcTroN 1 /2'=1' OÉTAIL LANE FIELÐ - PLAN VIEV ?4, ?o?l.-.€:O, p¡efeffed) o o APPE¡IDD( A SOILS AND PERCOLATION REPORT CCI ENGII\IEERING/CRONK CONSTRUCTION INCORPORATEI) I CCI EilGn{EERr{c 1lt1-2l'R¡oaü G¡and Junclfon, OO El5lt5Ctottk Cotpútactlqt lnc, Grand Junction (970) 640-5û29 . Glenwood Springs/Aspen (9'10> 640-5ù29 . MontroselDelta (970) 640-5029 Emait ccigi@msn.com SOILS AND PERCOII\îTON REPORT Date: Prepared by: October 22,2021 Thomas A. Cronk, P.E. I 13l -24- Road Grand Junction, CO 8l 505 974-&0-5029 Client:John Placek PO Box 455 silr, co 8t652 970-379-1t96 crystalconst@sopris.net Properly address: -TBD Scutter Lane, Rifle, CO 81650 TaxscheduleNo.: 212-72-8+0&388 Iægal Descript.: l-0 Soils Evaluation The site consists of approximately 35.8 acres of uncultivated native soil. Drainage is approximately lW/o to the south-east. A percolation teslsoils evaluation was conducted on the property of referenoe on l0l22l2l by Tom A. Cronlq registered professional engineer (R.P .8.). "the perc pxcavation trench was Iocated approximately 6W'south of the north property line and approximately 180' east of the west property line. tlnre perc excavation trench was e4tørded to a depth of 108" below gound surface (BGS). There was no evidence of ground water or high seasonal water table in the open excavation to a depth of 108' BGS. The soils evaluation indicares three distinct soil horizons underlie the site. A lithologioal description follows: depth (in.) descrip'tion 0" -24" 24" -60" 60'- 108" silty clay, Iight pinkish tan; blocþ (USDA - silt loan, blocþ, weak structure) sandy clay, light red; blocþ (USDA - sandy loam, block¡ weak structure) silty clay red; hard and smeared (USDA - silty clay,platy; strong structuie) 10 Percholes were consfructed at the surface and at a depth of approximately 36 in and 66 in. The holes appeared to be well saturated at the time of the test. Results of the percolation test aro shown in Table 1. TABLE 1 Pcrcolation Tc6{ Rcsults -TBD- Scuüer Lanc Depth Timeon l0t22l2l Timc Drop Perc Ratc min/in12:,43 12:57 l4:05 0" -12"6.0 6.5 8.125 82n.tzs 39 36"-A8'',6.0 6-875 8.625 t212.6'2s 3l 66":18 4-O 4-t25 4.5 wo_s t(Å 2.0 Limitations This document is representative of the site conditions disclosed at the specific time of the site investigation. Site conditions are subject to change from external events both manmade (irrigation ø water feature construction) and naturally occurring (flooding or excessive precipitation). CCI Engineering/Cronk Consûuction Incorporated is not responsible and acc€pts no liability for any future variation in site conditions. CCI Engineering/Cronk Constn¡ction Incorporated represents fhis report has been prepared within the limits prescribed by the owner and in accordance with the cunent acc€pted practice of the civil €ngin€ering profession in the area- No wananty or r€prssentation either expressed or implied is included or intended in this report or in any of our contacts. SEAL A. Cronk, Date 3<,) '8t'3æ 11