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HomeMy WebLinkAboutMT BALDY ESTATES PHASE 1 TR AOnsite File b UT, Municipality of Anchorage, P.O. Box 196650 0 4700 Elmore Road Anchorage, Alaska 99519-6650 0 (907) 343-7904 0 Fax (907) 343-7997 http://www.muni.org/Onsite Development Services Department On -Site Water and Wastewater Section Waiver#: OSVI81029 COSA#: Permit#: OSP171215 PID#: 050-762-18 Legal Description: Mt. Baldy Estates Phase I Tract A Engineer: Donna Mears Applicant: Shane Durand Department Your request for a waiver of the required 100 feet horizontal separation from the septic tank to the private well has been approved. The approved separation distance is 65.0 feet. See engineer's waiver request letter for justifications. This waiver approval applies to the proposed private well only. Any future upgrade to the on- site wastewater disposal system will require all separation distances be met or another approval from this department. a a V M a M K a a a a 1. a is K M a x 0 a a U 0 2 a a K a M a a a M 2 x a a x x M U K H a M a " K a x x a a M U H a U M a 2 a M x a M a a 01 M a x K 0 M a M 11 1 Waiver is Granted: x Waiver is not Granted: 7 Date: Approved by: Name of Reviewer a M x a K M M a a. a In III V a. a K a K K N a a a 2 K . a.1 1128 Donna C Mears, PE June 12, 2018 Municipality of Anchorage Development Services Department On-Site Water and Wastewater Program 4700 South Bragaw Street Anchorage, AK 99519-6650 Subject: Mt Baldy Estates Ph I, Tr A Well separation distance waiver request Dear On-Site Services Staff: On behalf of Shane Durand, this request is being made to waive the separation distance requirements between the well and septic tank from 100’ to 65’. It is likely that a well can be placed greater than 65’ from the tank, but since there are limitations with site accessibility, the separation request is being made conservatively. There is sufficient space on the lot for placement of the well outside the standard separation distance, however there are concerns about the service line length and burial depth. Although sufficient receiving soil was found for the septic system, uphill from the system required blasting into bedrock for the house and driveway. As such, there is significant concern for freeze protection for burial of a 120’ service line in what is currently solid rock. This geology significantly limits other well locations. The area at the southeast corner of the residence would provide a much closer service line, although would need to be drilled prior to the construction of the residence. Due to the rock face at this corner, a waiver from the well to the septic tank would be required. The septic system was installed last fall, and the location of the tank optimized to retain minimum pipe drop and tank cover. The well would retain a 100’ minimum separation distance to the disposal fields. As can be seen in the site plan submitted for the permit, original slopes were steep, although they have now been flattened in this area by the removal of bedrock. The house sits between the well and septic tank. The majority of this lot extends downhill across the Golden Eagle Drive, and further downhill is several hundred acres owned by the State of Alaska. This lot is 8+ acres, and lots 2 & 3 are 7+ acres. Since this parcel is surrounded by state, municipal (Mt. Baldy trailhead and parking lot), and commercial land (for the radio tower), the well logs to the north and west were investigated for water conditions. The wells in lots 2, 3, and 5 were drilled through various types of bedrock to depths of 205’, 400’ and 400’ respectively. Their static water levels are 27-44’ below ground surface. The well logs do not identify water bearing layers, and with the bedrock it is likely water is entering through multiple fissures in the bedrock being replenished further uphill. The wells in Silverwood Hill Estate #1 (Lots 1A, 1B, and 1C), to the west all had similar conditions with well depths of 400’, and static water levels of 26-44’ bgs. This consistent presentation of bedrock conditions significantly reduces concerns for a reduced separation between the well and septic tank. �oegjas paeA Veq ,o 1 cu 0 m co cu CV O Y t0 I— ry a IY U cu J (D Ln0) o 3. a a cu o 3 >, N U- 1 y I _^ W CN U N • z N w a W�/ LL H A ' ti 1 27.11' z O � W P4 • H wQ z z a •� �x0 N FC, C7 C F, d' H N \ ,� Q x z N Oz r3:4 O w I- >M 0 C) ti LO a) OC) Cf) U) N U) IJJ 0 m N oN 0 z 9,ras U J'o m m u 3 a� 3 ac w N d w m a Z-- ztnF W �D I O (y C7 OC) O \a Lw Q 4--J �D (N U) 0 G4 0 CT co ry 0 +,'L �LL: ull- �� ��• Z UV le H A ' ti 1 27.11' z O � W P4 • H wQ z z a •� �x0 N FC, C7 C F, d' H N \ ,� Q x z N Oz r3:4 O w I- >M 0 C) ti LO a) OC) Cf) U) N U) IJJ 0 m N oN 0 z MUNICIPALITY OF ANCHORAGE ,,,;,,, On-Site Water&Wastewater Program �, PO Box 196650 4700 Elmore Road Anchorage,Alaska 99519-6650 Phone:(907)343-7904 Fax:(907)343-7997 http://www.muni.org/onsite Dipartint nt pN�M UA^GE On-Site Water & Wastewater System Permit Permit Number: OSP171215 Effective Date: 8/23/2017 Work Type: WellSeptic Initial Expiration Date: 8/23/2018 Tax Code Number: 05076218000 Site Legal Address: MT BALDY ESTATES PHASE 1 TR A G:0355 Site Mailing Address: Owner: DURAND SHANE Lot Size in Sq Ft: 358796 Design Engineer: Mears Donna Total Bedrooms: 6 This permit is for the construction of: 2 Disposal Field 0 Septic Tank 0 Holding Tank 0 Privy 0 Private Well 0 Water Storage All construction shall be in accordance with: 1. The attached approved design. 2. All requirements specified in Anchorage Municipal code Chapters 15.55 and 15.65 and the State of Alaska Wastewater Disposal Regulations (18AAC72) and Drinking Water Regulations (18AAC80) 3. The wastewater code requires inspections during the installation. The engineer shall notify the Development Services Department per AMC 15.65. Provide notification by calling (907) 343-7904 (24/7), 4. From October 15 to April 15, a subsurface soil absorption system under construction during freezing weather shall be either: a. Opened and Closed on the same day, or b. Covered, sealed, and heated to prevent freezing Special Provisions: 1. An additional test hole shall be provided at time of construction (TH-3 on site plan). Test hole shall demonstrate separations to groundwater and impermeables, as well as confirm percolation rate used in design. If the results require a design change, construction of the drainflelds shall stop pending On-site review and approval of a change order. Please submit stamped and signed soils log with inspection report. 2. An additional percolation test shall be provided at time of construction (TH-4 on site plan). If the results require a design change of the alternate drainfield, a change order shall be submitted for approval. Please submit stamped and signed percolation test log with inspection report. 3. A sieve analysis shall be done on the recycled glass aggregate, if used, to demonstrate it meets the specifications for filter sand. Submit sieve analysis with inspection report. G"1` - A/a/04A & 23 ZOf7 Received By: Date:attejt �/� Issued By: fi1 ,l C�' Date: Rier20/7 Municipall y of Anchorage P.O. Box 196650 0 4700 Elmore Road Anchorage, Alaska 99519-6650 0 (907) 343-7904 0 Fax (907) 343-7997 http://www.muni.org/Onsite Development Services Division On -Site Water and Wastewater Program illlt., A - v a Waiver-#: OSVI71081 COSA#: Permit#:OSP171215 PID#: 050-762-18 Legal Description: Mt Baldy Estates Phase 1 Tract A Engineer: Donna Mears Applicant: Shane Durand Your request for a waiver of the required 50 feet horizontal separation from the absorption fields to the excessive slope has been approved. The approved separation is 17.0 feet for the southern fields and 0.0 feet for the northern and alternate fields. In addition, your request for a waiver of the required minimum 10 feet horizontal separation between fields has been approved. The approved separation is 6.0 feet. See engineer's letter and drawings for justifications. This waiver approval applies to the proposed absorption fields (primary and alternate) only. Any other future upgrade to the on-site wastewater disposal system will require all separation distances be met or another approval from this department. ❑ The affected adjacent property owner(s) have been given a 7 day notice regarding this waiver. ❑ Notarized letter(s) of nonobjection have been received from the owner(s) of the affected adjacent property. ® Adjacent properties are not affected by this waiver. 0 0 0 0 0® 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 O 0 0 0 0 0 0 0 0■ 0 0 0 0 0 0@ E 0 0 0 0 0 6f 0 0 0 H 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 Waiver is Granted: X Waiver is not Granted: Date: Approved by: _ 9 09-)LrL'X Name of Reviewer m® m Q a® s® m m® m® e M®® a® K s C 0 0 H 0® 0 0 9 e e® a a® m s®®®®®® H Q®® a 0 s 19 a® a e e® it a 0 e a a®® m 0 0 m® m® a 0 0 1 MUNICIPALITY OF ANCHORAGE ti , Community Development DepartmentPhone: 907-343-7904 Development Services Division Fax: 907-343-7997 On-Site Water & Wastewater Program ON-SITE SEWER/WELL PERMIT APPLICATION Parcel I.D. 050-762-18 Property owner(s) Shane Durand Day phone 350-6062 Mailing address 19646 S Mitkof Loop Eagle River, AK 99577 Site address Golden Eagle Drive Eagle River, AK Legal description (Sub'd.. Block & Lot) Mt Baldy Estates Ph 1 Tr A Legal description (Township, Range & Section) Lot Size 358,796 Sq. Ft. Number of Bedrooms 6 APPLICATION IS FOR: APPLICATION IS AN: TYPE OF DWELLING: (M all that apply) Absorption Field n Initial Single Family (SF) 0 (w/wo ADU) Septic Tank 0 Upgrade ❑ Duplex (D) Lf Holding Tank ❑ Renewal (l Multiple Dwellings Privy ❑ (SF and/or D) Private Well ❑x Water Storage El THIS APPLICATION INCLUDES A VARIANCE I WAIVER REQUEST FOR: Slopes - see attached - �r tk. -k cL-�,I , _Q _l Distance: t1/4.1/(1 ; (, p I certify that the above formation is correct. I further certify that this is in accordance with applic. •leu cipal des. .na ' re of property owner or authorized agent) Permit/Rush Fees: 60 f 916:: )g Waiver Fees: g15 Date of Payment: 0lR Iii dc 4 Date of Payment: $"11 hi C-k- 3149 Receipt Number: 01400 Receipt Number: 21 50245 Permit No. 65'i l l a l S Waiver No. 05V (1 1 OS Permit App_ ': .t Donna C Mears, PE August 4, 2017 Municipality of Anchorage Development Services Department On-Site Water and Wastewater Program 4700 South Bragaw Street Anchorage, AK 99519-6650 Subject: Mt Baldy Estates Ph I, Tr A Septic System and Well Design and Permit Application Dear On-Site Services Staff: On behalf of Shane Durand, this application seeks to obtain a permit for a private well and septic system to serve a new 6 bedroom single family home. This subdivision consists of 5 lots, of which this is the last to request a septic and well permit. The lots are substantial (7.5+ acres), and the two 40 acre lots to the east are owned by Eagle River Parks and Recreation. The majority of the subject lot extends across Golden Eagle Drive. The proposed development of this lot will not limit the development of adjacent parcels. As demonstrated in this application, this system is designed to have no impact on: • the wells in the area, nor those to be constructed in the future; • existing septic systems in the area or those to be constructed in the future; • reserve space, either surface or subsurface, on any lots located in the area: • off-site drainage. Soils and Vertical Separation Distances A test hole was excavated during the subdivision process (attached), and shows good percolating (---4.5 minutes/inch) receiving soils from a depth of 2' to 7' below ground surface (BGS). Bedrock was encountered at 10' BGS. No groundwater was encountered during excavation, during the groundwater monitoring period, nor during a site investigation this May. An additional test hole will be excavated during construction to verify soils to the south for the southern portion of the proposed primary septic system. It is expected that the soils will fall within the 1.2 gpd/ft2 application rate criteria as do the existing test hole and the one across the road on this lot. Waiver request A waiver is requested to utilize the criteria established under the proposed code 15.65.201 for disposal fields which was approved by the On-Site Technical Review Board this April, and is in the queue for approval by the Anchorage Assembly. The primary designed disposal area is located on a bench on an otherwise sloped lot. The majority of the primary disposal field on the bench is on slopes less than 25%, however, there are some small sections that are up to 35%. The northern and southern trenches are being constructed to different specifications to best mitigate potential slope impacts, as well as allow for additional splitting of the flow between the disposal fields which will mitigate differential loading from uneven flows. The northern trenches are designed to steep slope standards with a couple portions of disposal field through a 35% slope. This includes a one foot filter layer below the trench to assure a 36" minimum depth from the top of the native organic layer at the downslope side of the fields. The bottom of the drain rock is designed at 4 feet BGS on the upslope side.The potential for daylighting was investigated, and found a 25% max. slope from the bottom of the invert to the edge of the road at the steepest part. Additionally, soils are well draining. As such, no additional design considerations are needed to reduce potential for daylighting. The southern trenches are designed on a flatter portion of the bench, with the steepest portion of the disposal fields at 16% slope. These trenches are designed to conventional disposal field standards with an effective depth of I foot..The southernmost portion of this pair of disposal fields . is uphill from a more steeply cut bank along Golden Eagle Drive, so the trenches are designed with an impermeable barrier on the southern wall to the bottom of the effective depth. This will mitigate the potential for daylighting with less than 25% slope from the bottom of the impermeable barrier to the intersection with Golden Eagle Drive, which is 35' horizontally from the road at the closest point. Construction is planned to be staged from the uphill side of the disposal fields to preserve downslope vegetation. Any downslope areas which may be disturbed will be revegetated. The disposal field is proposed to be in four segments with three flow splitters that will divide the flow proportionately into the four proposed wide trenches. The splitting of the flow will assure even distribution to the disposal fields and significantly reduce potential for disproportionate loading. The separation distance between the fields is also per the proposed code at 6 feet. Recycled Glass Aggregate as Filtration Layer Mr. Durand would like to utilize recycled glass aggregate (RGA) for the filtration layer in the northern disposal trenches. This was discussed by the On-Site Technical Review Board during the code re-write, and no additional restrictions or requirements were placed on utilizing RGA, as long as it meets the specifications for filter sand. If RGA is not available which meets the proposed specifications, we will discuss with staff utilization of alternative available material, such as traditionally available aggregate. Owner Installation Mr. Durand would like the option to do an owner installation of the septic system. Please find more information on Mr. Durand's experience on the attached "Septic System Owner-Installer Agreement' . As per the proposed code, this application is being transmitted without the current requirement for an original signature, as I am working remotely. If an original signature is requested, I can provide it on or after August 17, 2017. If you have any questions or wish to discuss this application further please do not hesitate to call me at 907-632-6382, or email mears©alaska.net. Respectfully, ( ' fr/7a C J Donna C. Mears, P.E. • Response to Comments Mt. Baldy Estates Ph I Tr A Following is the response to comments from the On-Site Water and Wastewater program dated 8/17/2017. Changes have also been made to the attached site plan. 1. Symbols for the location of existing and proposed test holes have been added to the drawing. 2. An additional proposed test hole (TH-4) for confirming percolation rate for the reserve disposal field has been identified on the site plan. 3. Following is the profile drawing for the southern disposal fields for which a slope waiver is requested. A projected 25% slope from the bottom of the disposal field would daylight at least 35' from the disposal field. 16% • Maintain vegetation or Impermeable stabilize any disturbed soil 25%o barrier through revegetation. 35' 4. The reserve area is designed to the steep slope conditions of the proposed code including: a The separation distance from the bottom of the drain rock and the bedrock shall be a minimum of 6' measured from the upgradient side of the disposal field. b. The trench does not exceed 5' wide. c. There is a paved driveway immediately west of the drainfield at the same elevation, and all remaining ground downhill will be vegetated. d. A one foot filter sand layer is placed below the disposal field at a 36" depth from the top of the native soil on the downslope side. e. The northern disposal fields have the same design, except they are located on a bench with a 25% max. slope, and there is no driveway downslope. Driveway 4' Downhill slopes <46% ie 2g% 36` _ A Maintain vegetation or rade SAO o 60" r 6' stabilize any disturbed. Or-�n ?rd\ectea25/° 35' > bear°ck Note: Illustrations show the most extreme conditions along the disposal field. I .........- i t l' ' Legal - Mt. Baldy Estates Ph I, Tr A TH-22% Design Criteria r / Bedrooms– 6 I i / 7 6.5 .' Septic Tank size–2,000 gallons / Design flow–900 gpd 1'3 • / 1" Proposed Depth to groundwater– 10 + / 0 p Percolation rate–4.6 minutes/inch ,v % 7 Well Depth to bedrock– 10 ft. ' 1X' Location 38.2 Design Specifications (Northern Wide Trenches) 1 Steep slope construction Application rate – 1.2 gpd/ft2 4, / , �' , fi Effective area required –375 ft2 i 100 well o 0. Bottom of trench –4 ft. below ground surface @ uphill 2 / A radius Effective depth –0.5 ft. / / / Sand filter– 1 ft. deep / ,,o i j', . ops- • ` s TceofGabbns / Trench width –5 ft. .o H-4 •erc) \ / Required field length –901.f. (2 @ 451.f.) / 170 / Design Specifications (Southern Wide Trenches) ' " �(5. Septic 8.0, , c. a, reserve to. i Additional TH proposed / cc's' et area area S ` v Slope - <20% = �'f 0, S o, _ _. Application rate – 1.2 gpd/ft2 Northern °°�,ae Effective area required–375 ft2 disposal fields Bottom of trench–4 ft. below ground surface © 1 I Effective depth– 1 ft. �� 49.2 Reduction factor–0.87 �� e } \ •Trench width –5 ft. J Q� Southern I,P 0 '� +� '38 1 Required field length –78.31.f. (install 2 @ 401.f.) a°% disposal /0, 2% wImpermeable barrier along southern wall to bottom of \a��' fields e J , filter layer moo/ 1>70 / © ,r, I. t Design Specifications (Reserve) f 11. ': D Cat II advanced treatment (e.g. Advantex) / e"' a LI M� - Steep slope design @ 1i ; _ Application rate–4 gpd/ft2 0 2,000 O — 2 Gara�e: 1736. Upper Entry. Effective area required –225 ft gallon O Multipurpose:1710 /441(A Li] Bottom of trench –4 ft. below round surface @ uphill septic Main Levet 1760 �'�""�`– Z g p 0 Upper Level:1770 ``�\ti 1 l t i l w Effective depth –0.5 ft. tank s ar _4,1,,E Trench width – 5 ft. • p. " S,f* -�pi w 0 30' N 49LLI 1 1 0 . th V • 1i . L'41"n C M1la '. a ...- Z Z Lowest Grade: 1736 '4 .• .. '1.A Legend: i s. Q Clean out � w (2 adjacent sweep towards each other) t 111‘‘‘‘" Cr p G Monitoring tube o - 0 0 0 0 0 0 0 tv o ch NI- t... u7 VD I's. CO Q 0 Flow splitter . I1- �' ce A Testhole cn. D Base drawing and building layout by ECI t113beJUN a ' zom Municipality of Anchorage "-;. '' ' "� $ ` t� � Fti Development Services Department ,,. r+'•` <;� p,; %.1.7 17f Building Safety Division 04.A e 4:0 On-Site Water and Wastewater Program 111' ` tt gi • � 4700 South Bregaw St. ft •��� tt �. � P.O.Box 196650 Anchorage.AK 99519-6650 .,, , { • orufonsite t4 .��, A.-r. f?.: rs=is; (907)343.7904 •`io.sill-E e'N Soils Log - Percolation Test >7w Performed For CMM General Contractors Del*Performed:3/18/Zo Legal Desert- •n: Lot 1,a SiiIickyision of Lot 2 Township,Range,Section: NW 114 of NE 114,Sec.6,T14N,RIW,SM r� Slope Site Plan f rc,,G"1- A Depth Feet) AVOW Or.anic Silt OL ,root mat., 1Nolitiol - M4brown,frozen to 0.5',moist, See Site Plan 2- E 4.14▪-r▪ t:Sand with Silt and Gravel 3- 14;)." 405?(SP-SM),brown,moist. 4-:tE1'j - 5-*1E ; Lfi 6- 7- 4',' Gravel with Silt and Sand 8_ GP-GM),brown,moist. -b" `� ♦I°• 1I WAS GROUND WATER 9-' E ENCOUNTERED? No 1.10- �+, BedYDCk• F YES,AT WHAT DEPTH? �; Depthto Water After O 11- Monitoring? No Water 12- Total Depth 101. Dale:3/29/05 13- Komatsu PC 120 backhoe. 14- Reeding Date Gross Time Net Time Depth to Water Net Drop 15- 6" 3/18/05 5:45 pm 16- 3-15/16" " 5:55 pm 10 min 2-1/16" 17- 6" 3/18/05 5:56 pm 18- 3-13/16" 6:06 pm 10 min 2-3/16" 19- 6" 3/18/05 6:07 pm 20- 3-I3/16" 6:17 pm 10 rain 2-3/16" PERCOLATION RATE 4.57 (minutes/Inch) PERC HOLE DIAMETER 6" TEST RUN BETWEEN 4.25 FT AND 4.75 FT COMMENTS PERFORMED BY: Russell Hepner,E.I.T. I Allan W.Murfitt CERTIFY THAT THIS TEST WAS PERFORMED IN ACCORDANCE WITH ALLSTATE AND MUNICIPAL GUIDELINES IN EFFECT ON THIS DATE.DATE: March 18,2005 MUNICIPALITY OF ANCHORAGE / 4r Community Development Department \46 ,� Phone: 907-343-7904 On-Site Water & Wastewater Program ti.� Fax: 907-343-7997 Septic System Owner-installer Agreement A real estate property owner(Owner) may install their own septic system. The department may issue an approval for a homeowner to perform work on a conventional (not AWWTS) on-site wastewater disposal system to serve that individual's owner-occupied, single-family or duplex home if the homeowner satisfies and agrees to the following requirements. The property owner and excavation equipment operator may perform work on no more than one owner installed project in a 12-month period. As owner of (legal description) Mt. Baldy Estates Ph 1 Tr A I agree the following items are true and accurate. 1. My experience installing septic systems is as follows. I have 25 years of civil construction experience in Alaska and a civil engineering degree from the UAF. I have supervised as a project manager and home owner install of septic systems in Eagle River and the Matanuska Valley and personally installed systems as the laborer and 2. operator at remote locations along the Dalton Highway, Tok and Nome. 3 The name of the excavation equipment operator is. Shane Durand 4 There will not be compensation for installation services rendered. 5 I will be actively involved with the septic system installation at all times. 6. The name of the inspecting engineer is Donna C. Mears, PE I agree to discuss the following items with the inspecting engineer: a. Permit design criteria and specifications. Inspection requirements set forth in AMC 15.65.150. b. 2-hour minimum advance notice given to the On-site Water & Wastewater 7. c- Program for all required municipal inspections. I agree any changes I make to the items listed above will require a new approval before 8. performing work. I agree to have the project-specific On-site Wastewater Disposal System Permit available at the construction site for the dur-tion of all related work. Owner's printed name: ShII / . d ff. Owner's signature: f,Iii i Date: B 07 4, Septic System Owner Installer •!reement_Feb2015.doc