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HomeMy WebLinkAboutMCCABE EAST Lots 1-6 Tract A Plat#83-344 S-6305 ,,' ~ ' MUNICIPALITY OF ANCHORAGE ~ DEPARTMENT OF HEALTH& ENVIRONMENTAL PROTECTION ENVIRONMENTAL HEALTH CASE REVIEW WORK SHEET CASE NUMBER NAME [~ [ ~ FOR MEET NGOF CASE ~ ~ ~0~j O~~ REVIEWER'S COMMENTS: / · /. ~ / ,.// . ~ ~/ .. , ..... ~, - ~ ( ~ - I 71-014 Rev. 2/78) ,Fane 2, 1982 Planning and Zoning, ATTN: Jerry Weaver Department: of Hea'lth and Environment~] Protection, Environmental Health,Division Cas~s Due For Review With N~w Comment~ on Case This office has reviewed th~ following cases an~'~ has t'h~? following Case J'ohn Lynn ~:(:nvironmental Specialist ~24/e Lots 1 - 6, and Tract A, McCabe SubJ~.ivisJ. ol% This subdivison soils report shows lots port on-site septic systems. However, ali. lots ~'nust ]lave 10,00O square feet less tsqan 25% slo~e as to support septic ~]ystems. This requests redesign :3ince Lots 2 ~nc~ 3 bare greater than 40% slome and no suihabJe outside a drainage swale for trench The cutbanks of six (6 feet or more must have a 75 foot setback frot proposed s~wer locations. August 31, 1982 Les Bucholz Municipality of Anchorage Department of Health and Enviromental Protection 825 L Street Anchorage, Alaska 99502 ? 1982 RECE.! ED Regarding: McCabe Subdivision East S-6305 Dear Les, In reviewing our meeting yesterday, I wanted to clarify the discussion regarding the 100 foot creek septic setback. Does this area exclude computation for septic sytem and drainage courses? If so, then approximately 3.2 acres of usable land would be considered undevelopable. Obviously this factor is detrimental to the development of McCabe Subdivision East. Could you please clarify the above, particular]yl in regards to your 10,000 square foot requirement. Thank you. Si nce rely, HEWITT V. LOUSNBURY & ASSOCIATES cc: Eileen McCabe 'Alaska Testlab 4040 "B" Street Anchorage, Alaska 99503 .H.V. Lounsbury & Associates 723 W. 6th Avenue Anchorage, Alaska 99501' Attn: Mr. Darl Kausvger Subj: Percolation Tests for McCabe Subdivision Dear Darl: Phone (907) 278-1551 ( Telecopier (907) 272-5742 ) September 10, 1982 W.O. #A20327 MUNICIPALITY OF ANCHORAGE DFPT, 0p Hc''I-T~ ''% ENVtRONMch,~A .... O, ECTION 1982 RECEIVED At your request we have reviewed the percolation data for the above referenced subdivision. We would like to offer the fol- lowing classifications and corrections to our report dated March 22, 1982 on this property. The size of the test holes drilled was about 6 inches in diameter. A four inch, solid flight auger drills a hole about that size. The test holes presoaked for 24 hours were Test Holes 1, 2, 4, and 5. Test Hole 3 was not soaked, nor a percolation test run, because of access problems. Though the actual measured rates for Test Holes 2 and 5 were 10 minutes and 11 minutes respectively, because of the fine grained nature of the soils, which have a tendency to- plug with time, we recommend a more conservative design value of 20 min~es/inch. Below is a table showing the percolation rates and corre- sponding soil layers. Test Hole #1 #2 ~4 #5 Perc Rate 25 minutes/inch 10 minutes/inch 34 minutes/inch 11 minues/inch Applicable ~ Layer J 8' to 16.5'~ [~/~-~ 6' to 19.0', 7' to 15.9' v- 4' to 16.5' /~1 w Each test hole was filled with water and allowed to soak for 24 hours. Upon returning the next day, 6 to - '--~ _ - . water was placed in the bottom of the tes~ hole and the rate ~t w~ich the water percolated out of the hole was measured at 10 minute intervals for an hour to an hour and a half by which time the perc rate had stabilized. The perc rate was th~n calculated to be the slowest value observed during this period. H.V. Lousbury & .~/~oc. September 10, 195. Page Two If you have any questions, please do not hesitate to call. Sincerely, ALASKA TESTLAB Melvin R. Nichols, P.E.' Manager MRN:kf ALASKA TESTLAB TO HEWITr V. LOUNSBURY 8 AS~'-~IATES Engineers - Surveyors 723 6th Avenue Anchorage, Alaska 99501 Phone 272-5451 GENTLEMEN: WE ARE SENDING YOU [] Shop drawings [] Copy of letter [] Attached [] Under separate cover via [] Prints [] Plans [] Change order [] [] Samples the following items: [] Specifications COPIES DATE NO. DESCRIPTION THESE ARE TRANSMITTED as checked below: [] For approval [] For your use [] As requested [] For review and comment [] FOR BIDS DUE [] Approved as submitted [] Approved as noted [] Returned for corrections 19 [] Resubmit [] Submit [] Return__ copies for approval copies for distribution corrected prints [] PRINTS RETURNED AFTER LOAN TO US COPY TO_ SIGNED: ~ If er)closures are not as noted, kindly notify us at once, TO ,HEWITT V. LOUNSBURY ~ AS;'-~IATES Engineers ~ Surveyors 723 6th Avenue Anchorage, Alaska 99501 Phone 272-5451 GENTLEMEN: WE ARE SENDING YOU ~ Attached [] Under separate cover via [] Shop drawin§s I::] Prints [] Plans [] Copy of letter [] Change order ~ [] Samples MIINIC!p,~UTy OF ANCHORAGE DEPT. OF HE'%T}I & ENVIRoNM:_~,~;AL J ,~O, ECTION the following items: [: 'J V ~ ~. ~ications COPIES DATE NO. DESCRIPTION g / THESE ARE TRANSMITTED as checked below: [] For approval For your use [] As requested [] For review and comment [] Approved as submitted [] Approved as noted [] Returned for corrections [] Resubmit [] Submit__ [] Return copies for aPproval copies for distribution corrected prints [] FOR BIDS DUE 19 I [] PRINTS RETURNED AFTER LOAN TO US REMARKS December 20, 1982 Municipality of Anchorage Department of Health and Environmental Protection 825 "L" Street Anchorage, AK 99502 Attention: Les Bucholz Reference: McCabe Subdivision East (S-6305) Dear Mr. Bucholz: There seems to be a concern over the slopes in the above mentioned subdivision. We examined lot 2 as it has the steepest slopes. After removal of the necessary area for the drainage easement, the remaining area of 25% and under slopes is 27,600 square feet. This falls within the Platting Guidelines for the Sewer and Water Program. By resolving the problem with the slopes we have satisfied your requirements and concerns, so we feel the plat should be approved by your Department. We hope this approval is soon and if there are any problems or questions, please contact us immediately. ~ Sincerely, HEWITT V. LOUNSBURY & ASSOCIATES Joe May JM/sw January 7, 1983 Municipality of Anchorage Department of Health and Environmental Protection 825 "L" Street Anchorage, AK 99502 Attention: Les Bucholz Reference: McCabe Subdivision East (S-6305) Dear Mr. Bucholz: We received a phone call from your staff on January 3, 1983. According to the conversation the above mentioned plat would be approved if we did the following: 1. Delineate on-site sewage disposal areas. We have attached the preliminary plat with proposed sewage disposal areas indicated for each lot. 2. Resolve 100' creek set back. 0 We contend that the area in question is simply a drainage and not a river, lake, stream or a source of domestic water supply; therefore, your remaining minimum set back distances (Anchorage Municipal Code, Section 15.65.060 paragraph C) and required easements shall control. Indicate depth of percolation test. The percolation tests were run in the absorption layer of the soil which was noted on the last soils report we submitted. We feel we have accomplished this and await your approval. questions, please contact us immediately. Sincerely, HEWI~ V. LOUNSBURY & ASSOCIATES Joseph G. May JGM/sw Attachments If you have any TO HEWrl-r V. LOUNSBURY ~t AS~IATES Engineers - Surveyors 723 6th Avenue Anchorage, Alaska 99501 Phone 272-5451 GENTLEMEN: WE ARE SENDING YOU /~ Attached [] Under separate cover via [] Shop drawings [] Prints [] Plans [] Copy of letter [] Change order [] [] Samples the following items: [] Specifications COPIES DATE NO. DESCRIPTION THESE ARE TRANSMITTED as checked below: [] For approval [] For your use [] As requested [] For review and comment [] FOR BIDS DUE [] Approved as submitted [] Resubmit [] Approved as noted [] Submit [] Returned for corrections [] Return 19 copies for approval copies for distribution corrected prints __ [] PRINTS RETURNED AFTER LOAN TO US REMARKS COPY TO If enclosures are not as noted, kindly 1-11-83 RE: Case ~6305 McCabe Subd. East John I have several observations and comments on the McCabe Subdivision which may be of some help to you. These are as follows: The contour interval is not indicated on the plat. By correlating the slope profile shown on one plat (without the contour lines shown) with the plat with the unidentified contour lines, it is apparent that the contour interval is 4'. I called Planning/Zoning and they didn't know the interval. I called Joe May (Lounsbury and Associates) and he advised that the interval was 4' I calculate the percent of slope across an area at right angles to the contours at the disposal sites shown on the plat. These slopes are as follows: Lot 1 = 17.4% Lot 3 = 25.4% Lot 5 - 8.9% Lot 2 = 27.8% Lot 4 = 25.5% Lot 6 = 15.1% These slopes are shown like this (in pencil) on the plat ® The areas delineated on the plat' as "on-site disposal areas" are approximately 40'x50' or 2000 square feet in area. This does not satisfy your previous request for delineation of 10,000 sq. ft area with less than 25% slope for disposal areas I have outlined (blue shaded) areas on lot no. 1, 4, 5, and 6 which are 10,000 sq. ft. with less than 25% slope. It should be noted that the outlined disposal area on Lot no. 6 falls within the drainage area. The location of the test holes on Lot no's. 1, 4, and 5 is not within an acceptable distance from the proposed disposal area. Lot 1 2 4 5 Test hole 3 located 195' from disposal site No test hole Test hole 2 located 155' from disposal site Test hold 1 located 60' from disposal site The contour map definitely indicates a major drainage course situated roughly between Lot no. 2 and 3. The severity of the slopes on Lot no. 2 and 3 and the terrain up-slope from Lot no. 2 and 3 indicates the high probability that this is indeed a major drainage course and is probably seasonally a flowing creek. The 100' set back should be applied along this drainage course. MCCABE SUBD. EAST PAGE 2 The soils and percolation test results are not presented on MOA "Soils Log - Percolation Test" form (72-008). The for- mat submitted does not show slope, site plan, percolation test data, or percolation test interval. In the letter from Alaska Testlab dated September 10, 1982 in paragraphs 3 and 4, it is shown that test hole 2 had a perc rate of 10 min./inch and test hole 5 had a perc rate of 11 min./inch. From the soils description and sample infor- mation, test hole no. 2 shows ML/SM soil, damp to wet, very stiff from 6.0 to 19.0 feet. Test hole no. 5 shows ML soil (sandy sift), damp, hard from 8.0 to 16.5 feet. I strongly doubt that with these prevailing soil characteristics, per- colation rates of 10 and 11 minutes per inch are realistic. More realistic rates would be 30 to 45 minutes/inch. In the letter from Alaska Testlab dated September 10, 1982, paragraph 5 it states "Each test hole was filled with water and allowed to soak for 24 hours. Upon returning the next day, 6 to 12 inches of water was placed in the bottom of the test hole and the rate at which the water percolated out of the hole was measured at 10 minute intervals ...... " Using this testing procedure, only the bottom section of the test hole was acturaly perced. From the soils description, the test holes should have been perc tested through the following approximate intervals: TH 91 5' to 8' TH 92 6' to 8' TH ~3 5' to 7' TH ~4 5' to 7' TH ~5 5' to 8' Also by "filling the hole with water" (to total depth of the test hole) it is very questionable whether the maximum head requirement doing the perc testing was observed. Robby Robinson 1-11-83 D1/c/JL. L1 January 17, 1983 Corps of Engineers Regulatory Functions Branch NPACO-RF-S P.O. Box 7002 Anchorage, AK Reference: 99510 McCabe Subdivision East and Furrow Creek Dear Sirs: Please classify the drainage in the above mentioned subdivision (i.e., stream, creek, drainage, etc.) and if it is a wet lands area. Also indicate what restrictions govern the area and in particular septic tanks and absorption areas. We appreciate your help and if you have any questions, please call. Sincerely, HEWITT V. LOUNSBURY & ASSOCIATES J6~4/sw Attachments DEPARTMENT OF The ARMY ALASKA DISTRICT, CORPS OF ENGINEERS P,O, BOX 7002 ANCHORAGE, ALASKA 99540 January 28, 1983 REPLY TO ATTENTION OF: Regulatory Functions Branch Special Actions Section Mr. Joseph G. May .Hewitt Vo Lounsburry and AssOciates 723 West 6th Avenue Anchorage, Alaska 99501 Reference: Juris. Determination McCabe Subdivision East Rabbit Creek Anchorage, Alaska Dear Mr. May: This letter is in response to your January 14, 1983, request for a wetland determination for McCabe Subdivision East (NW1/4SE1/4sec. 27, T. 12 N., R. 3 W., S.M.). Our review of aerial photographs, soil survey data, and topographic information indicates that McCabe Subdivision East contains two minor drainages. However, the property is not located-in wetlands that are under the Corps of Engi. neers.re§ulatory jurisdiction. Therefore, no Department of the Army permit is required for the discharge of dredged or fill material onto this property. You should contact the Municipality of Anchorage regarding restrictions governing septic tanks and absorption areas. Should you have any additional questions, please contact this office at the above address, ATTN: NPACO-RF-S, or call Mr. James Wood at (907) 552-4942. CF: EPA, Anchorage Municipality of Anchorage, Planning Department Municipality of Anchorage, Building Safety Department Sincerely, ~Reed~r~ Chief, Special Actions Section Regulatory Functions Branch TO ;HEWITT V. LOUNSBURY 8 AS;~'-~IATES Engineers - Surveyors 723 6th Avenue Anchorage, Alaska 99501 Phone 272-5451 Department of Health and Environmental Protection 2-23-83 jJo~ "~2-010 ^~TEN~'°~obby Robinson RE* McCabe Subd. East GENTLEMEN: WE ARE SENDING YOU ~Attached [] Under separate cover via [] Shop drawings [] Prints [] Plans [] Copy of letter [] Change order [] [] Samples the following items: [] Specifications COPIES DATE NO. DESCRIPTION 1 2/23 Letter stating what we have done 2 Revised Plat THESE ARE TRANSMITTED as checked below: ~iFor approval [] For your use [] As requested [] For review and comment [] FOR BIDS DUE [] Approved as submitted [] Approved as noted [] Returned for corrections 19 [] Resubmit__ [] Submit [] Return copies for approval copies for distribution corrected prints __ [] PRINTS RETURNED AFTER LOAN TO US REMARKS COPY TO February 23, 1983 Municipality of Anchorage Department of Health and Environmental Protection 825 "L" Street Anchorage, AK 99502 Attention: Robby Robinson Reference: McCabe Subdivision East (S-6305) and Phone Conversation February 18, 1983 Dear Mr. Robinson: We have shown the 50-foot septic system setback and have delineated possible locations for on-site septic systems (3 per lot as requested). We ask for a waiver on the request for a test hole on Lot 2 as the existing soils report does not indicate any real change in soil conditions. The cost of re-mobilization of a drill rig for one test hole and the material analysis of the soil from one test hole seem extreme for the approval of this plat. We would appreciate a response on the approval as soon as possible. We would also appreciate a set of design requirements for on-site septic system for plat approval (such as the adjusted values for Absorption Field Areas, 30- foot Absorption Field Area separation, required distance from test holes to Absorption Field Areas, etc.) Si ncerely, HEWITT V. LOUNSBURY & ASSOCIATES ~. 'May JGM/sw Attachments POf~6-650 ANCHORAGE, ALASKA 99502-0650 (907) 264-4111 TONY KNOWLES MA YOR DEPARTMENT OF HEALTH AND ENVIRONMENTAL PROTECTION March 8, 1983 Joseph G. May Hewit~ V. Lounsbury & Associates 723 W. 6th Avenue Anchorage, Ak 99501 SUBJECT: McCabe East Sub-division, S6305 Dear Mr. May: This will acknowledge receipt of your letter dated February 23, 1983, and will furnish our responses to your queries contained therein. On the map attached to your above reference letter, you depicted the locations for the disposal systems on each proposed lot, and you also delineated a 50' setback from the existing surface water seasonal drainage course. Upon review of your letter and map, our responses are as follows: SETBACK FROM DRAINAGE COURSE: Inasmuch as the drainage course running generally Northeast to Southwest (near the lot lines between Lots 2 and 3 and Lots 5 or 6) is basically a seasonal drainage course, this office will accept the 50' setback for drainfields. We are still of the firm opinion that the severe slope on Lots No. 2 and 3 are such that an on-site disposal system cannot be located on each of these two lots in their present proposed configuration. According to the topo map we have, the slopes on these lots are as follows: LOT NO. 2 Nor~most d~sposat site Middle disposal site Southmost disposal site Slope 29% to 32% 35% to 38% 29% to 32% HEWITT V. LOUNSBURY ~t AS?~,IATES Engineers - Surveyors j 723 6th Avenue Anchorage, Alaska 99501 Phone 272-5451 ATT[NTt ON GENTLEMEN: WE ARE SENDING YOU ~ Attached [] Under separate cover via [] Shop drawings [] Prints [] Plans [] Copy of letter [] Change order [] [] Samples the following items: [] Specifications COPIES DATE NO. DESCRIPTION THESE ARE TRANSMITTED as checked below: [] For approval [] For your use [] As requested [] For review and comment [] FOR BIDS DUE [] Approved as submitted [] Resubmit [] Approved as noted [] Submit [] Returned for corrections [] Return 19 copies for approval copies for distribution corrected prints [] PRINTS RETURNED AFTER LOAN TO US REMARKS COPY TO If enclosures are not as noted, kindty notify us a~oonc~ March 28, 1983 Municipality of Anchorage Deparatment of Health and Environmental Protection 825 "L" Street Anchorage, AK 99502 Attention: Robby Robinson Reference: McCabe Subdivision East (S-6305) Dear Mr. Robinson: In our last submittal we located ~]e disposal sites on overall slopes of 25% or less. In our present submittal we have located disposal sites between topo lines and indicated slopes, and where we were unable to locate between just two topo lines we have indicated between which topo line we computed our slopes. We would appreciate your reviewing our present disposal site locations on Lots 2 and 3. Please note that the information on on-site setback, minimum distances and soil adjustment tables were not attached in your last letter. Please attach in your next letter. Sincerely, HEWI~T V. LOUNSBURY & ASSOCIATES Joseph G. May JGM/sw Attachment Ancho 'age DEPARTIyIENT OF HEALTH AND ~:NVIRONMENTAL PROTECTION F'"~C H 6-650 ANCHORAGE, ALASKA 99502-0650 (907) 264-4111 TQNY KNQWLES, MA YOR April 19, 1983 Joseph G. May Hewitt V. Lounsbury and Associates 723 West 6th Avenue Anchorage, Alaska 99501 Subject: S-6305: Mc Cabe East Subdivision This will continue correspondence on the subject subdivision endfng w~th your letter dated March 28, 1983. We are still concerned with the items #2, 3 of our letter dated March 8, 1983, which addresses the critical slope on Lots 2 and 3 and the apparent descrepancies from the R-6 minimum lot size of 54,450 square feet. Based on the information available from the existing topography maps, the slope on Lots 2 and 3 are such that Lots 1, 2, 3 should be combined into two(2) lots. By relocating the cul-de-sac, Lot 6 could be enlarged and Lots 1, 2 and 3 combined into two(2) lots. This would solve the slope problem and bring these lots to within the~minimum size criteria of R-6. In your above referenced letter, you requested information or minimum setback distances and soil., adjustment tables. This information is included in your copies in "Procedures - Soils and Percolation Testing" and "Design of On-site Disposal Systems". In the event you have misplaced them, we have ~nclosed additional copies hereto. If there are any further questions, please call this office at 264-4720. Sincerely, Robert W. Robinson Environmental Engineering Manager RWR/ljw Joseph G. May Hewitt V. Lounsbury & Associates Marach 8, 1983 Page 2 LOT NO. 3 ~.~o~_ Northmost disposal site 25% to 27% Eastmost disposal site 17% to 20% Westmost disposal site 31% to 34% \ We respectfully suggest that Lot Numbers two and three be combined with a disposal site then located at or near the Southeast one-third of the lot. The minimum gross lot size for R-6 zoning is 54,540 sq.ft. The lot sizes shown on your plat for each of the six lots is less than 54,540 sq.ft.; however, we adjusted each lot size for the adjacent easements and determined the approximate gross lot size. These adjusted gross (and net) lot sizes are as follows: R-6 Net Lot Size Approximate Minimum Lot (sq. ft.) sq. ft. Lot Size No. (_R_e__~o_u_r__~_l_a_t_)_ Gross Lot Size ...S.gl.__f_t_.__ 1 45,000 53,250* 54,450 2 54,000 56,250 54,450 3 48,500 49,750* 54,450 4 52,500 68,750 54,450 5 34,000 52,580* 54,450 6 36,000 52,200* 54,450 *It still appears to us that Lot Numbers 1,3,5 and 6 fall below the minimum lot size criteria of R-6 zoning. The information you requested for on-site system setback minimum distances and soil adjustment tables are attached hereto. Should you have any further questions regarding the MCCabe Subdivision, please contact the undersigned at 264,4720. Sincerely, Environmental Engineer Project Manager cc: Mr. Jerry Weaver RWR1/e j/D29