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HomeMy WebLinkAboutSCENIC HEIGHTS S12052Onsite File enic zrc H ht eig 1 February 8, 2015 Municipality of Anchorage Building Safety Division On Site Water and Wastewater Program 4700 Elmore Street Anchorage, AK 99507 Attention: Debbie Wockenfuss: Subject: T11 N, R3W, Section 15, N2, NE4, NE4, NE4 Proposed Scenic Heights Subdivision S-12052 Septic System Feasibility Study Dear Debbie: We recently reviewed the proposed plat for Scenic Heights Subdivision with the intent of completing a subsurface soils study to identify areas suitable for the construction of on site septic systems to dispose of septic effluent to be generated from the houses proposed for construction on the newly created lots. The subdivision is located immediately east of Villages Scenic Parkway Drive in the Potter Valley area of South Anchorage. The subdivision to the north is fully developed with AWWU sewer and water. The subdivision to the south is served by on site septic systems and individual wells. The ground surface of the proposed lots in the subdivision slope steeply up from the ditch along Villages Scenic Parkway to the property line. The slope then flattens to approximately 10% to 25% in an easterly direction to the east property line. All septic systems proposed for the lots will be placed in areas where the surface slope is less than 25% which is the maximum allowed by the Municipality. Some surface slopes in the reserve areas or within 50' exceed.25%; but only slightly and for short distances. These slopes can be flattened with minor grading and will not prevent the successful placement of septic systems on these lots. The cross slope on the property is nearly flat. The proposed absorption systems and reserve areas are placed parallel with the contours at locations where the slope is the shallowest. Test holes were placed on the proposed lots in early September of 2010. Water monitoring has been ongoing with readings last taken on October 15, 2010. At no time has groundwater been noted in the holes. The purpose of the test holes was to assess the underlying soil conditions and to determine whether septic systems could be placed on the lots to serve single-family homes. The test holes were placed to depths of up to 17' with no bedrock or impermeable lenses of material encountered. The locations of the test holes were determined in the field by the soils technician for ease of access and to prevent destruction to the existing trees and fragile terrain. At the time of the Scenic Heights Subdivision February 8, 2015 Page 2 exploration access was off of Villages Scenic Parkway and extended to the east end of the new subdivision. Percolation benches were constructed at various depths in the holes, but primarily 4' to 5' below the original ground surface. A percolation cavity was prepared to determine the absorptive characteristics of the soils encountered. The cavity was presoaked in accordance with Municipal requirements and a percolation test performed. The results of the tests are included in the attached documentation. In every case silty gravel (GM/ML) with varying degrees of silt was encountered to the bottom of each test hole.. The percolation rate in this material ranged from 34 to 54 minutes per inch. All lots have percolation rates which qualify for use with a standard gravity flow septic system. All work was completed under the direction of technicians and engineers at Anderson Engineering. The results of the percolation tests and test hole logs are included as well as the water monitoring results. A monitor tube remains in place in each hole to determine the groundwater elevation over a period of time. No groundwater has been noted to date and none is expected. The bottom of any absorption system must be constructed a minimum of 4' above the highest recorded groundwater elevation in accordance with Municipal requirements and State law. Based on our field study and water monitoring completed to date it appears all lots of the proposed subdivision are capable of supporting an onsite septic system. A 16,000 square foot reserve area is shown on each of the proposed lots for septic system construction. In addition, Test Hole Logs and a Location Map are included which illustrate soils encountered, percolation rates and their respective location on the individual lots. Sincerely, Michael E. Anderson, P.E. Attachments �.� 49th _ __•' � MICHAEL E. ANDERSON J No. CE -4381 ,�: J ' // • Performed For: Legal Description: J+I (Feet) 1- 271 2- 3- 4- 5- 6- 7- 8- - 3- 4-5- 6- 7- 8- 10- 11- 12- 13- 14- 15- 16- 17- 18- 19- 20- 10- 11- 12- 13- 14- 15- 16- 17- 18- 19- 20- COMMENTS Municipality of Anchorage Development Services Department Building Safety Division On -Site Water and Wastewater Program 4700 Elmore Road P.O. Box 196650 Anchorage, AK 99507 www.ci.anchorage.ak.us (907) 343-7904 Soils Log - Percolation Test �� . G NEER'SpSe A, vF, 491 '97a�. /�..Od.ee OD.oe.�e�soee �. • - _• James Staengel Date Performed: Township, Range, Section: "_4 C -v % > uC-v%> AVY 6TWL- WAS GROUND WATER Date ENCOUNTERED? Net Time Depth to Water S IF YES, AT WHAT DEPTH? % L Depth to Water After 0 P Monitoring? ./ E Date: I {Q 1 O 4oA9 17 J ............................. oMICHAEL E ANDERSON a !�* CE - 4383 � tn ESSI001m � � Site Plan °o Reading Date Gross Time Net Time Depth to Water Net Drop 2� MiA5 IS:SG9 '� �,alou 3o MINS T7 I PERCOLATION RATE �j'r (minutesrinch) PERC HOLE DIAMETER -7 TEST RUN BETWEEN FT -AND 'ZFT PERC CAVITY WAS PRESOAKED PRIOR TO TESTING PERFORMED BY: A. Harala -Prtf I CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE WITH ALLSTATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE: Performed For: Legal Description: f� M-1 2- 3- - 3- 6- 7- 8- 9- 10- 11- 12- 13- 14- 15- 16- 17- 18- 19- 6- 7- 8- 9- 10- 11- 12- 13- 14- 15- 16- 1718- 19 COMMENTS COMMENTS Municipality of Anchorage Development Services Department Building Safety Division yet On -Site Water and Wastewater Program 4700 Elmore Road P.O. Box 196650 Anchorage, AK 99507 www.ci.anchorage.ak.us (907) 343-7904 Soils Log - Percolation Test GINEER' 6A 9 mo o° 49 T A doge mos esoo. ` lose c. o..oe..o,o o.a seed '.00/OOOOD906po..... ...... -MICHAEL E. ANDEp_co J .`,ct: e 6 J, C7 E - 4381 James Staengel Date Performed: Township, Range, Section: Site Plan WAS GROUND WATER ENCOUNTERED? �I IF YES, AT WHAT DEPTH? L 0 Depth to Water After p Monitoring? E Date:. t le 1 d "-,i 101.'51)6 /jo'j' ` 1 5f,_ Reading Date Gross Time Net Time Depth to Water Net Drop lip 3e, MWIS Its° P.0tl +1 a! �a7i �r d 31 - 3 � 3 ,twirls ra, 66 6"IS& PERCOLATION RATE (minuteslnch) // PERC HOLE DIAMETER 7 �• - TEST RUN BETWEEN FT AND FT PERC CAVITY WAS PRESOAKED PRIOR TO TESTING PERFORMED BY: A. Harala I CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE WITH ALL STATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE: Performed For: Legall Description: lfl Municipality of Anchorage Development Services Department Building Safety Division On -Site Water and Wastewater Program 4700 Elmore Road P.O. Box 196650 Anchorage, AK 99507 www.ci.anchorage.ak.us (907) 343-7904 Soils Log a Percolation Test ' o00 oeoo ooaoo coo��,°��`'°�oeoe °..• WCHAEL E. AiVDERSC%N a e' • � F Q°. CE - 4381 •°\� James Staengel Date Performed: —D ; A 4- 5- 6- 7- 8- 9- 10- 11- 12- 13- 14- 15- 16- 17- 18- 19- 20 - COMMENTS 4-M �Yy Township, Range, Section: WAS GROUND WATER e ENCOUNTERED? (� S IF YES, AT WHAT DEPTH? / L 0 Depth to Water After / p Monitoring? E Date: 4 t to Site Plan Reading Dra_te Gross Time Net Time Depth to Water. Net Drop p� 5-, C' mids i1 ,$1�►- i %r311m PERCOLATION RATE (minuteslnch) PERC HOLE DIAMETER TEST RUN BETWEEN r C5, FT AND _ G _FT PERC CAVITY WAS PRESOAKED PRIOR TO TESTING PERFORMED BY: A. Harala I CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE WITH ALLSTATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE: Legal Description: Depth (Feet) ?) 7- 8- 9- 10- 11 12- 13- 14- 15- 16- 17- 18- 19- 20 - COMMENTS 15T" Township, Range, Section: Site Plan WAS GROUND WATER I Date ENCOUNTERED? Net Time Depth to Water o V1. . sj IF YES, AT WHAT DEPTH? , oe•a°°, Municipality of Anchorage / O F GINEER' E Development Services Department 4cj TH Imo! S� Building Safety Division On -Site Water and Wastewater Program .1A 0 ' 4700 Elmore Road°aoY'�= P.O. Box 196650 Anchorage, AK 99507 =•O°° t) 0 °° MICHAEL E. ANDERSON = � www. ci.anchorage. ak.us� (907) 343-7904. `° �E - 4381 .° Soils Log - Percolation Test 0000° G� �0 PROFESS��®®©® Y Performed For: James Staengel Date Performed: -C.) 2ro 1 O Legal Description: Depth (Feet) ?) 7- 8- 9- 10- 11 12- 13- 14- 15- 16- 17- 18- 19- 20 - COMMENTS 15T" Township, Range, Section: Site Plan WAS GROUND WATER I Date ENCOUNTERED? Net Time Depth to Water / S IF YES, AT WHAT DEPTH? L Depth to Water After / O F Monitoring? E Date: Reading Date Gross Time Net Time Depth to Water Net Drop q ✓ 14 Iq,t,5 , _,­ _i it Imo! S� 3o Mi, .1A P'p8�1 Y D4- 21, PERCOLATION RATE tminutearinch) PERC HOLE DIAMETER TEST RUN BETWEEN p FT AND �.=j FT PERC CAVITY WAS PRESOAKED PRIOR TO TESTING PERFORMED BY: A. Harala I CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE ON ALLSTATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE: Municipality of Anchorage � ,'` 6E GINEER' S °,�®�: Development Services Department o giH b Building Safety Division aoo.ppoo „o,• On -Site Water and Wastewater Program o0 00 4700 Elmore Road °•° °e°.e°.r , e S P.O. Box 196650 Anchorage, AK 99507 MICHAEL E. ANDERSON www.ci.anchorage.ak.us '+� oo CF 4381 (907) 343-7904 `� ff �.oz 1a• °� �® �, -Z7- Soils Log - Percolation Test �����RofFss�oN®a Performed For. James Staengel Date Performed: 201 O Legal Description: 1- 3- 4- 7- 8- 9- 10- 11- 12- 13- 14- 15- 16- 17- 18- 19 - COMMENTS r�-o M 0 L I yr- y l l � Township, Range, Section: Site Plan WAS GROUND WATER ENCOUNTERED? S IF YES, AT WHAT DEPTH? L 0 Depth to Water After P Monitoring? E Date: jD lip Reading Date Gross Time Net Time Depth to Water Net Drop V11 145 L., c G^ PERCOLATION RATE (minutes/inch) PERC HOLE DIAMETER —7 TEST RUN BETWEEN- FT AND 4,5: FT PERC CAVITY WAS PRESOAKED PRIOR TO TESTING PERFORMED BY: A. Harala An ( CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE WITH ALLSTATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE: Municipality of Anchorage Development Services Department Building Safety Division ® y`i On -Site Water and Wastewater Program 4700 Elmore Road P.O. Box 196650 Anchorage, AK 99507 www.ci.anchorage.ak.us (907) 343-7904 Performed For: Legal Description: ,ice 3- 4- 5- 6- 7- 9- 10- 11- 12- 13- 14- 15- 16- 17- 18- 19- 20- Depth (Feet) .r' Soils Log - Percolation Test t : ENGINEE ) ° res' ?n % All Ci -!A.-1 a ANDERSON o �� ,,�OFtSS1��'�., James Staengel Date Performed: Township, Range, Section: G tai WAS GROUND WATER ENCOUNTERED? 4 S IF YES, AT WHAT DEPTH? L Depth to Water After D P Monitoring? E Date: Ito to l0Ai_/10 -- lgo..(r` a�e_F� 9fte (-A-, C:' 0 Site Plan Reading Date Gross Time Net Time Depth to Water Net Drop � �{ t � 3 v l••tt tvS , v fo n 6, �g � I �o •�t� 3v P•lIMS 7. �2�, it O. �� PERCOLATION RATE (minutesAnch) PERC HOLE DIAMETER {� TEST RUN BETWEEN FT AND FT - COMMENTS PERC CAVITY WAS PRESOAKED PRIOR TO TESTING PERFORMED BY: A. Harala I CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE ITH ALL STATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE: Performed For: Legal Description: 'T�1 Municipality of Anchorage Development Services Department Building Safety Division On -Site Water and Wastewater Program 4700 Elmore Road P.O. Box 196650 Anchorage, AK 99507 www.ci.anchoraoe.ak.us (907) 343-7904 Soils Log - Percolation Test James Staengel Date Performed: Township, Range, Section: �� e GINEER' ,SEA _'4 9 / s 3000a eoaooaooc oz qo eoroeseoo �' {' o ovooeoa0000a c coeeoeee0000000eo,r a i �lCdi aFL Y N,i11DEP,S0N - ® s,' CE - 4381 PTOFrsjj0i� O(�ff- 7- 8- 9- 10- 11- 12- 13- 14- 15- 16- 17- T %moi 18- 19- Site Plan WAS GROUND WATER ENCOUNTERED? / S IF YES, AT WHAT DEPTH? L Depth 4o Water After �— D P Monitoring? E Date: /Zopra Reading Date Gross Time Net Time Depth to Water Net Drop I9F 2 3 o S It , Z tel e� i ; oo ,t O� O a�l�l Is -It ,."� ti PERCOLATION RATE 3 (minutes/inch) PERC HOLE DIAMETER �% r TEST RUN BETWEEN ,� FT AND i 5C' FT COMMENTS PERC CAVITY WAS PRESOAKED PRIOR TO TESTING PERFORMED BY: A. Harala r I CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE WITH ALLSTATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE: Performed For: Legal Description: 2- 3- 4- 5- 6- 7- 8- 9- -3- 4 -5 -6 -7 -8- 9- 10- 11- 10- 11- 12- 13- 14- 15- 16- 17- 18- 19- 20 - 12 -13- 14- 15- 16- 17- 18- 19- 20 - COMMENTS COMMENTS Municipality of Anchorage Development Services Department Building Safety Division �r On -Site Water and Wastewater Program 4700 Elmore Road P.O. Box 196650 Anchorage, AK 99507 www.ci.anchoraoe.ak.us (907) 343-7904 Soils Log - Percolation Test om 3_/-,e 4ENGINE SEAL. f °77 49 v MICHAEL I- ANDERSON : <' 1 4381 ver iz—moo o° �� .sem James Staengel Date Performed: I I� o o Township, Range, Section: A-rivt S e— Site Plan WAS GROUND WATER ENCOUNTERED? IF YES, AT WHAT DEPTH? / L Depth to Water After O P Monitoring? E Date: Its I Z7 /Vo:dPL ° 1za— Reading Date Gross Time Net Time Depth to Water Net Drop �9 13 �� IS•13 j �•�'� / �'It0 dMims.0{9'� 9rp ti 6,4�r F'tKUULA I IUN RATE (minuteslnch) PERC HOLE DIAMETER TEST RUN BETWEEN FT AND FT PERC CAVITY WAS PRESOAKED PRIOR TO TESTING PERFORMED BY: A. Harala � I CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE WITH ALLSTATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE. DATE: February 9, 2015 Municipality of Anchorage Building Safety Division On Site Water and Wastewater Program 4700 Elmore Street Anchorage, AK 99507 Attention: Debbie Wockenfuss Subject: Scenic Heights Subdivision, S-12052 Water Availability Study Dear Debbie: We have collected information on several wells in the area of the proposed Scenic Heights Subdivision to estimate the possible depths and production rates of wells to be constructed in the future on Lots 1 through 4. The subdivision directly north of this proposed subdivision is served by the AWWU water and sewer system. The area to the east is undeveloped. The primary source of information is the subdivision and three lots directly to the south. The wells on this subdivision are 40' to 150' from the proposed wells for this subdivision. The information obtained from these wells is indicative of the characteristics expected of the wells proposed for Scenic Heights Subdivision. Field investigations indicate all of the wells were constructed with the presence of bedrock from 62' to 186' below the surface. All wells are cased to and grouted into the bedrock level. In all cases the wells produce a sufficient amount of water and range from 230' to 325' in depth. SCENIC HEIGHTS SUBDIVISION WATER AVAILABILITY STUDY LEGAL DESCRIPTION WELL DEPTH PRODUCTION - LOG PRODUCTION - TEST The Villages, Lot 1 267' 4 GPM Scenic Heights Subdivision February 9, 2015 Page 2 The Villages, Lot 2 230' 12 GPM 6.5 GPM The Villages, Lot 3 256' 5 GPM Paradise Valley, Block 1, Lot 1 325' 6 GPM It is obvious from our study that any wells to be constructed in Scenic Heights Subdivision in the future will be placed to depths of less than 300' and will be cased to bedrock at depths ranging from 60' to 100'. The production rates will be sufficient to support a four bedroom home and can be expected to be between 4 and 8 gallons per minute. The wells will not affect the operation or output of the existing wells in the area. Sincerely, Michael E. Anderson, P.E. Attachments AV ` 49th ;•MICHAEL E. ANDERSONAV :r No. CE -4381 •' �® ®'® ®®11®®®SS\ok®®®