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Home My WebLink AboutBETTY W Lots 1 & 2 S-7547 MUNICIPALITY OF ANCHORAGE DEPARTMENT OF HEALTH & ENVIRONMENTAL PROTECTION Enwronmental Health D~ws~on CASE REVIEW WORKSHEET CASE NUMBER S-7547 SUBDIVISION OR PROJECT TITLE Betty W. Subdivision DATE RECEIVED March 28 1984 COMMENTS DUE BY April 16, 1984 ,~'--~7 Gilfilian Engiheerlng & Environmental Service.,, TEST ItOLE LOG Pro3ect ~rame: ProSect Number: Sozl ~bsorptlon Syste~ £or Lot 45 Sec 9,T15~4Rl);~SJL Helmut's Inc. Excavating & Landscaping 8155 ,7_e_st ~lo!e rumber: Date of Test Hole: Test Hole ~ocatlon: Approx. 12' from end of czst iron pzpe from septic tank outlet., Method of Excavation: Exmsting trench excavated for soml absorption sy Lo~ed By: Bob Gilfzlzan, P.E. 0.0' , 0.5' -- :o-"qU 4.0, :: '.".: Y i".' tr,...'-.. 5o5' -.~ .. Organic Iiat, forest litter, etc. Silty Sand (loam) w/ some organics and roots Oli~e bzo~;n · ~ Sandy Gravel ~-/ same cobbles Broom Poorly Graded Sand (fine) S~ndy GP~[ VEL Ground Water Table, T.D. Gilfilian Engineering & ., % ~yx~.~,~-------'~ % Bob Gdfihan. P.E Environmental Services Box 6364 o PaLmer, Alaska 99645 (907) 376-3005 October 21, 1981 I,'~. Chuck Staschel Helmut's Inc. Excavating & Landscaping SR Box 1245 chuglak, AK 99567 Lot 45 Sec 9, T15N, R1W, S.M. Lot owner- Ray Anderson Dear Mr. Staschel: This letter is to provide you w~th an engzneering report on the subsurface so~ls conditions found on the above referenced lct. As per your request, I viszted the sub3ect lot on October 17 and 18, 1981, and observed a deep trench excavation. It was my under- standing the trench was excavated at an earlier date for the pur- pose of ~nstallzng an on-site wastewater soil absorption system to serve a proposed two(2) bedroom dwelling. Attached for your review is a copy of a soil log of the trench excavation. This log nas made on the soil structure located at approximately 12 feet from the end of the septic tank cast iron outlet p~pe. It is important to note that the soil struct'~e and layering along the length of the trench xfas no~ consistent. Thzs log however, ~s rather reoresentat~ve of the general so~l conditions. It shoald also be posnted-out that the ground x~ater elevations ~lcng ~his trench was not constant,s.c., the ground x~ater tended to rise in elevation as one proceeded away from the septic tank. Specifi- cally, at 24 feet from the beginning of the trench nearest the sep- tic tank the water level was approximately 6 inches h~gher xhan that found at 12 feet from the begznnzng of the trench. These ob- servations · ndicated & spr~ng(a ground~ater recharge area) r~y be present on the opposite s~de of this lot. In any event, ~t appears that the watertable elevations in the vicinity of the septic tank may be sufficiently deep to permit.the 2nstallatxon of an on-slte seal absorption system. In addition, I noted the ~nvert on the d~scharge end of the 10 £oog section of cast iron pzpe located on the outlet end of the exzstzng septic tank nas approximately 5'6" above the groundwater table mea- sured 12 feet along the trench from the end of the pipe. Also, th~s cast iron pipe was laid at a depth of approx~rately 1.7' belo~ the existing ground surface. Engineer Report Helmut's Inc. Page 2 10/21/8. in ccrs~derat~on of the above described sate conditions, It is my rccczzendation the.proposed soil absorption system consist of a ~na!lc,: seepage bed. The effluent d~strzbutlon system should con- s~st of 4" diameter perforated p~pe laid level with 6" of screened - ~ below _ ,o~.. nlaoed the pipe and 2" of rock placed above the ~ipe. This distribation system should be connected to the existing cast ir~n pipe from the septic tank thus allowing for gravity fl~,~. It i~ rogumred that the bottom of the screened rock medma be placed ~ a depth to orovide a mmnimum of 4 foot vertical separatmon above x:.c ~bove described groundwater elevation. Further, the natmve ~!!~y lo~_n somls must be removed and replaced with clean sandy gra- vel hack£mll ma~ermal placed up to the bottom of the screened rock. size of the above soml absorption system is dependent on the '~an~:y cf ~.e sewage flow and ~nflltrat~on caoacl~y of the sub- ~-f~¢e soils. Sased on the visual a~d textura~ characteristics ~e underlying sandy so~ls, a wastewater applxca~ion rate of ~ra!lons ocr day oe~ scuare f6ot of absorption ~ was derived. ~io~in~ fo--~a 1.5 m~lt~?]~ca%~-~--~~£~ sizing see~a~ bess. ~o~al oo~tom absorp~zon 9rea reeu~red_:o~ the ~ub~e~_t_2 b_~edroo~ 6~ei~nM ~s 4~u squaz'e xcel,3 The recommended dem~ns~ons o~-{h~S~ep- bed snouzd ne '~5' wide by ~0' long. The layout~nd ~nst~llation %ne d~strib~t~on system shou%d be made ~n ac~rdah~'f~~4 ,un~c~oal~y spec~f~c~ions~ Lust!y, a minimum of 2 inch thick r~g~d styrofoam lnsul~ation should be placed directly over the screened rock media and a minimum oi 2 feet of earth cover should be placed over the styrofoam. The mound- ed surface over the entire seepage bed should be smooth to allow for positive drainage to prevent surface ~ater from standing and/or ponding the ~ound surface. if additional information is needed on the above matters please do not hesitate to call upon me at your convenience. Bob Oilf~ian, P.E. Con=ultmng Engineer (An~uorage Hunicipality Certificate #ST81-035) \ , V C H MA .E,, C 340 E Znd Ct,Suite ZOO,ANChORAGE, ALASKA 99~1 ~~- (907) 2~6 ~zs ~ ~ Oct. 16, 1984 John Lynn Dept. of Health & Env. Protection 825 L St. Anchorage, Alaska 99501 Re: Case #S-7547 Betty W. Subdivision. Letter of Intent. Dear Sir: Raymond and Betty Anderson of SR 1, Box 2683, Chuglak, Alaska 99567 are:intending to drill a well on Lot 2 of the Betty W. Subdivision in the spr~ng of 1985. ~ REJ,Jr:mlj ROBERT E. JOHNS, JR., R.L.S. MEMBER OF ALASKA SOCIETY OF PROFESSIONAL LAND SURVEYORS