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CHUGIAK SCHOOL General Information
A clkorage P.O. BOX 6650 ANCHORAGE, ALASKA 99502-0650 (907) 264-4111 TONY KNOWLES, MA YOR DEPARTMENT OF HEALTH & HUMAN SERVICES August 30, 1985 Bill Tanner Director of Facilities and Maintenance 1301 Labor Pouch 112080 Anchorage, AK 99511 Dear Mr. Tanner: This letter is to provide you with a written report concerning a code compliance inspection conducted at the Chugiak High School pool on Monday, August 26, 1985. by representatives from the Anchorage School District~ the Municipality of Anchorage Department of Parks and Recreation, and Health and Human Services~ and State of Alaska Department of Labor Standard and Safety Division-Mechanical Inspections. Maintenance personnel have been able to clean the pool to a satisfactory level by the use of a new method that effectively removed the brovm film on the side and bottom of the pool. Because the water source for this pool has a high iron content a vigorous cleaning program will continue to be necessary to prevent this brown film from building up and preventing Kood visability of pool users by the lifeguard° The walls, floors and ceilings in the men's rest room and shower area have been repaired and are in very good condition. The women's restroom and shower areas are clean and in acceptable condition with the exception of the doors to the toilets which are badly rusted and an area on the left side of the corner wall at the doorway to the shower room on which the paint is badly peeling. In both the women's and men's locker rooms there are several large worn out areas on the floor that need resurfacingo It was also noticed that there is no auto controller on the chlorine gas system (which is not considered a problem as per A1 Edmondson, Pool Engineer, Parks and Recreation) but the gas mask or self contained breathing apparatus needs to be located in close proximity to the chlorine gas compartment. Bill Tanner August 30, 1985 Page 2 The chlorine gas compartment is not heated as required by Alaska State Regulation 18 AAC 30o540.Go This compartment needs to be heated to prevent freezing of the chlorine and equipment lines° Ail of the wash down hose bins are required to have a vacuum breaker° In summary, the Chugiak High School pool was in good condition with respect to maintenance and cleanliness and satisfactory for operation as of August 26, 1985o We request that your office advise us as to when the discrepencies as noted above~ ioe., the locker room floor, the doors in the girls locker room, the cement block, the ceiling paint~ and the lack of a heat source in the chlorine room, ~tl be corrected. We will also begin copying our routine inspection reports to your office and the principal of the appropriate school's pool, so that the school district can he more aware of potential problems in the future° If you have any questions or if I can be of further assistance to you, please call me at 264-4721o Sincerely, Margaret Do DeStefano Environmental Sanitation Program Manager MD1/dEH4 DEPT. OF ENVIRONMENTAL CONSERVATION ;~2HORAGE/~-~TE1LN DIS~ICT OFFIC~ 437 "E" STI~EET, SUITE 303 ANCHORAGE, AI~ 99501 July 16, 1985 ~wl Engineers 4040 "B" Street ;mchorage, Alaska 99503 BILL SHEFFIELD, GOVERNIOR A%'r~NTION: Paul Grib~n SUIt: Chugiak High Sch~l Septic System, C~nugi~k, Alaska 8621-DA-009 I~r Sir: We have reviewed the plans and specifications for the subject project and are hereby issuing this approval letter which constitutes the l~rmit required by A.S. 46.03.720(a) for construction of the sewerage system. Cover material over septic system must be a ~zinimumof four feet in depth. It should be ren~red that final approval will necessitate the sub~zis- sion of Engineer R-Built Plans and o~;ners name, address and telephone number. This will consequently mandate that a professional engineer conduct basic inspection of this project so as to be able to sign off on as-built plans. Arra~ge~nt for this inspection work is the responsi- bility of the developer. ~h~y future expansion of subject project will require ~lditional approval frem this office. Sincere ly, E. District Engineer S~/dd cc: P~bbieRobinson, MOA TO COFFMAN ENGINEERS, '~ ~C. 550 W. SEVENTH AVE., SUITL-.~a0 ANCHORAGE, ALASKA 99501 (907) 276-6664 Municipality of Anchorage Environmental Health Division ~?R "I" Stree~ Anchorage, Alaska 99501 8, 1985 .~R. Robinson ~H~H~,,~¢~(~cLoF ANCHORAGE Sy~'~EpT. OF HEALTH & SEPTIC ~qON~L PROTEC?!O~ JUL 3 1985 GENTLEMEN: WE ARE SENDING YOU F~ Attached El Under separate cover via [] Shop drawings ~ Prints ~ Plans [] Copy of letter ~] Change order Fi delivery Samples the following items: Specifications COPIES DATE NO DESCRIPTION 1 5/20/85 System Calculations - DOWL Engineers 1 May 1985 Soils Report THESE ARE TRANSMITTED as checked below: U~ For approval Y~ For your use [] As requested L] For review and comment L3 FOR BIDS DUE Fj Approved as submitted ~ Approved as noted [] Returned for corrections 19 ~] Resubmit__ [! Submit L] Return copies for approval copies for distribution corrected prints PRINTS RETURNED AFTER LOAN TO US REMARKS Robby; 1) The system automatically alternates between the two fields - by the siphon mechanisms. 2) Backfill over fields varies from 4' to 15', generally about 15'. If you have specific questions. Feel free to contact Paul Gribbon, DOWL Engineers, 562-2000. COPY TO. File Scott L. Mohr, P.M. Coffman Engineers, Inc. MUNICIPALITY OF ANCHORAGE DEPT, OF HEALT;[ & ENVIRONMENTAL pROTECTION June 26, 1985 J U L ! :1985,~ Mr. Robby W. Robinson Municipality of Anchorage Environmental Health Division 825 "L" Street Anchorage, Alaska 99501 SUBJECT: CHUGIAK HIGH SCHOOL ADDITION Dear Mr. Robinson: Transmitted herewith are copies of your review comments, dated May 21, 1985, and the on-site sewage system specifications. These were inadver- tently omitted from the review submittal of June 24, 1985. Sincerely, Scott L. Mohr Project Manager 177.3 c: 84117-02 550 W. Seventh Avenue, Suite 700 / Anchorage, Alaska 99501 / Phone (907} 276-6664 102 t 112th Avenue N.E. / Bellevue, Washington 98004 / Phone (206) 453 8092 4145 N.E. Cully Boulevard / Portland, Oregon 97218 / Phone (503) 282 3141 Nt nicipality of Anch°Cage MEMORANDUM DATE: TO: FROM: SUBJECT: May 21, 1985 MiMi Meiser, Community Plan Department Manager, Environmental Health Division~/~ Chugach High School Addition and Renovation Project 1. There is nothing in the material recieved by the EHD which indicates any changes to the student load/staff load or any additional facility load. Also, there is nothing in the material recieved by the EHD which indicates any addi- tions or modifications to the existing on-site wastewater disposal system. 2. In checking with Mr. Steve Eng with the Alaska Department of Environmental Conservation, we are informed that they (ADEC) have not recieved any plans, drawings, specs or other information or the Chugiak High School Additions & Renevations. The ADEC comments must be obtained and reviewed by this office. 3. Sheet No A-3R indicates there will be some alterations/renovations to the CAFERTERIA/KITCHEN area. There must be plans submetted to EHD indicating in complete detail any modifications/additions to the existing facilities· These plans must then be reviewed and approved by EHD proir to the commencement of any co. ion. ~ Robby W. Robinson, Manager Environmental Health Division RWR1/srm RECEIVED COFFMAN ENGINEERS, INC. MAY 2 5 1985 PM GROUP. ANCHORAGE, AK Anchorage School District Anchorage, Alaska CHUGIAK HIGH SCHOOL On.Site Sewage Disposal System Specifications Dowl Engineers for TRA/Farr SECTION 02743 ON-SITE SEWAGE DISPOSAL SYSTEM PART 1 - GENERAL 1.01 DESCRIPTION A. This section covers the furnishing of all material, labor and equipment necessary to completely install the on-site sewage disposal system and appurtenances in accordance with the Contract Drawings. Building plumbing (to 5 feet +/- outside the buiiding) is not covered by this division. 1.02 APPLICABLE STANDARDS A. The latest revision of the following standards of the American Society for Testing and Materials (ASTM), the American Association for State Highway and Transportation Officials (AASHTO), the American Standards Association (ASA) and the American Water Works Association (AWWA) are hereby made a part of these specifications. ASTM C-478 - AASHTO-199 Specification for Pretest Reinforced Concrete ASTM C-1 50 Specification for Portland Cement AWWA C-151 Ductile Iron Pipe ANWA C-104 Cement Mortar for Ductile Iron Pipe AWWA C-110 Ductile Iron Fittings AWWA C-111 Rubber Gasket Fittings for D.I. Pipe AWWA C-104 & ASA A-21.4 Cement Mortar for Cast Iron Pipe ASA A-21.10 Cast Iron Fittings ASA A-21.11 Cast Iroe Joints 02743-1 ASTM C-76 Specification for Reinforced Concrete ASTM C-1 4 Specification for Non- Reinforced Concrete Pipe AASHTO M-45 Sand for Cement Mortar ASTM A-48 & ASTM A-438 Strength Requirements for Manhole Frames and Covers 1.03 DEFINITIONS A. Non-Frost Susceptible Material (NFS): Granular soils free of organic material and containing less than three (3) percent by weight finer than 0.02 millime- ters when compacted in place. B. Classified Material: Non-frost susceptible soils com- posed of unfrozen gravels and/or sands, well graded according to limitations set forth in the Unified Soils Classification System, which can be compacted to a tight.unyielding surface. C. Unclassified Material: Inorganic unfrozen soils, free of trash, peat, volcanic ash, debris, and frozen clods, which are capable of being satisfactorily com- pacted as required by the plans and these specifi- cations. D. Unsuitable Material: Soils material in the trench which, when excavated and properly protected from the effects of the weather, cannot be satisfactorily used as backfill, shall be classified as unsuitable and removed. Unsuitable material includes, but is not limited to, sand-clay mixtures, clays, silts with a plasticity index greater than 6, soils with high organic content, brush, stumps, trash, debris, large rocks and boulders, and frozen material. E. Subgrade: The surface upon which classified material is placed. 1.04 COMPACTION TESTING A. Where compaction density is specified, the maximum density shall be determined in accordance with the current requirements of AASHTO T-180o A correction for oversize particles should be applied in accordance with Alaska Test Method T-11, if appropriate. 02743-2 B. The in-place soil density may be determined by use of: Nuclear densometer - ASTM D-2922. Sand cone - ASTM D-1556. Rubber balloon - ASTM D-2167. Except for drainfieids, compaction tests shall be taken on each lift of fill or backfill, including trenches, at the average rate of one test per 5,000 square foot of area. Failing tests shall be re[es[ed at no additional cost to the Owner· A gradation test, in accordance with ASTM D-~22, shall be performed on each type of material used in fills and backfills. If material ia to be non-frost suscep- tible, hydrometer tests shall be performed in accord- ance with ASTM D-422. 1.05 SUBMITTALS The Contractor shall submit for approval manufac- turer's specifications, drawings, and recommendations for all materials and components incorporated into the project. The submittal shall include manufacturer's pubIished data, engineering data, Ietter of certifica- tion or certified test iaboratory report indicating that each materiai or component compiies with speci- fied standards and other requirements. Shop drawings shai1 be submitted for ali fabricated work. Contractor shall submit gradation test results for all Contractor furnished soils materials to be incorpor- ated into the project. Hydrometer test results shall be required for Contractor furnished classified soils materials to be incorporated into the project. PART 2 - PRODUCTS 2.01 DUCTILE IRON PIPE Ductile iron pipe shall conform to AWWA Specification C-151-81 with cement mortar lining conforming to AWWA C-104-80. Class 50 pipe shall be used, unless other- wise indicated in the specification or plens. Fittings shall be ductile or cest iron and all bell conforming to AWWA Specification C-110-82 except that so-called "shot[body" fittings~ otherwise meeting said AWWA Specification may be used. 02743-3 B. Rubber gasket joints shai1 conform to AWWA Specifics- tion C-111-80. 2.02 CAST IRON PIPE A. Ali cast iron shsll be thickness Class 22 centri- fugally cast. Cast iron pipe shsll hsve an iron strength of not less than 18/40 and shall have a mini- mum 1/16 inch cement mortar lining msnufactured and installed in accordance with ASA Specification A 21.4-80 (AWWA C 104-80). Cast iron fittings shall conform to current ASA Specifications A21.10, Class 150. Ooints and jointing shsll be mechsnicsl joints or push-on joints conforming to ASA 21.11. "No-Hub" pipe and "Ty-Seal" gaskets may be used. 2.03 PMS POLYVINYL CHLORIDE (PVC) SEWER PIPE A. All PVC sewer pipe shall conform to ASTM D3034-72 PSM SDR35 (extra strength) specifications. Elastomeric gasket joints will be required with assembly in accordance with pipe manufacturer's recommendations. Perforated PVC pipe shall have perforations located and sized in sccordsnce with AASHTO H-36, with the top row of holes approximately 45 degrees below the horizontal axis. 2.04 MISCELLANEOUS CONCRETE A. All concrete used in the construction of sanitary sewer systems with the exception of pr.cast manholes, manhole risers, cones, and RCR pipe shall have a mini- mum 28 day strength of 3000 psi with 4-7 percent entrained air and slump of 2-4 inches. 2.05 MORTAR A. Cement for mortar used in the construction of sanitary sewer systems shall conform with ASTM Specification Designation C-150, Type II; sand shall conform with AASHTO Specification Designation M-45. The mortar shall be composed of one (1) part cement and three (3) parts sand. The addition of lime is not permitted. 2.06 MANHOLES AND DOSING CHAMBER A. Msterisls used in the construction of manholes and dosing chamber shall conform to the requirements of ASTM Specification Designation C-478. Cones shall be eccentric, unless otherwise approved. 02743-4 B. Reinforced concrete pipe of the required inside dia- meter may be used for riser sections as an alternate. This pipe shall conform to ASTM Specification Designation C-76 with a minimum thickness of five (5) inches. C. Each precaat concrete barrel section, precast concrete eccentric cone section, concrete adjusting ring and manhole cover-frame shall be set and sealed by use of plastic gasket joint sealer as manufactured by K.T. Snyder Co., Inc., Ram-Nek Gasket Division, 9601 West Tidwell Street, Houston, Texas 77041, or equal. D. Cement for mortar used in the construction of manholes and dosing chamber shall conform with ASTM Specification Designation C-150, Type II. Sand shall conform with AASHTO Specification H-45. The mortar shall be composed of one (1) part cement and three (3) parts sand. The joints shall be made so as to produce a smooth, regular watertight surface. Only enough water shall be added to provide plasticity in placing the mortar. E. The tensile strength of the gray cast iron shall be 30,000 psi minimum as per ASTM A 438-64 and the requirement for transverse breaking load shall be 2,000 pounds as per ASTM A 438-62. Contact surfaces between frames and covers shall be machined to provide a uniform contact surface. 2.07 SANITARY SEWER CLEANOUTS A. Material used in the construction of sanitary sewer cleanouts shall conform to AWWA Specification C-151 for Class 50 ductile iron pipe and AWWA Specification C-110 for ductile iron and gray iron fittings. 2.08 INSULATION BOARD A. Density 2 p.c.f, minimum B. Compressive strength ASTM D1621-59T 35 psi minimum C. Water absorption ASTM C 272-53 0.25% by volume, maximum O. Conductance per inch, ASTM C177-63 0.23 maximum BTU/Hr sf-Degree F 02743-5 2.09 SEPTIC TANK (CONCRETE) A. The septic tank shall be a reinforced concrete with a liquid capacity of 15,000 gallons, fabricated to the approximate dimensions shown on the drawings. Pre-fabricated tanks of alternate dimensions but equal capacity may be approved at the discretion of the Owner's Representative. The tank shall be designed for the anticipated soil pressures. Contractor shall submit shop drawings for approval. Bo The tank shall have a minimum of two inspection openings, one over the inlet and one over the outlet. These openings shall be a minimum of 20", with a steel handle for access. The inlet, outlet, and inspection pipes shall be cask iron in the location shown on the drawings. The outlet invert shall be a minimum of 3" below the inlet invert. Both the inlet and outlet shall be baffled as shown or as approved by the Owner's Representative. The inlet baffle shall penetrate a minimum of 6" below the liquid level in the tank. The outlet baffle should extend below the liquid level approximately 40 percent of the total liquid depth, and at least as deep as the inlet baffle. D. Each precast concrete tank section shall be set and sealed as described under pr.cast manholes sections. E. The tank shall be sealed for watertightnesa with two coats of bituminous coating applied according to manu- facturer's recommendations. 2.10 FITTINGS Ac All couplings connecting the septic ~ank and sewer lines shall be flexible couplings for cast iron pipe. Couplings shall be Ferneo No. 1056-66 or approved equal. 2.11 FILTER FABRIC A. Fil~er fabric shall be permeable non-woven synthetic drainage fabric such ss Mirsfi 1~0 or approved equal. 027~3-6 PART 3 - EXECUTION 3.01 CONSTRUCTION STAKING A. The Contractor shall furnish the foliowing surveys for construction staking: Two offset hubs with guard stakes shai1 be placed to mark the offset and cut to the invert of each manhole, cleanout, junction, septic tank, and drainfieid corner. 3.02 LINE AND GRADE A. General 1. Horizontai distances are from center of pipe, or appurtenances, uniess otherwise noted. Siopes are calculated based on horizontal distances from inside face of manhoie to inside Face of manhoie or bottom of cIeanout. Fieid Checks 1. Prior to utilizing information such as bench marks, etc., it shai1 be the Contractor's responsibiiity to verify bench mark eievations by checking between at ieast two bench marks. The Contractor shaIi protect the bench marks and controi points provided by the Owner and properiy reference them. The Contractor shaii pay For any necessary repiacement. 2. AIignment and grade shaii be continuousIy checked by competent surveyor using transit and surveyor's IeveI during progress of work. Tolerances 1. Pipe toierance shaii be wlthin 0.03 feet oF design eievation with no ievel or reverse grade sections of pipe. Horizontal alignment to appear straight to the eye, and laid so that a full circle of light is seen when sighting through the pipe. 3.03 EXCAVATION A. General 1. Contractor shall accomplish all excavation required by the Contract Drawings through whatever materials encountered. All excavation shall be accomplished in accordance with the State off Alaska code and other safety requirements. 02743-7 2. Unauthorized excavation below the required grade line shall be backfilled with approved materiai and mechanically compacted to 95 percent of maximum density at the expense of the Contractor, except in the drainfieid ares. Over excavation in the drainfield area shall be~referred to the Owner's representative for resoption. Any additional testing and design cost~ shall be done without expense to the Owner. 3. In areas where large boulders, bedrock, or other unyielding material is encountered at the pipe bed eievation, the trench shall be undercut 6" and backfiiIed to the proper bedding eievation with minus 2" granuiar materiai compacted to 95 percent maximum density. 4. The Contractor shall separate the unsuitabIe materiai from classified and unciassified materiai during excavation to preclude subsequent undesir- abie mixing. The method of separation couid inciude, but not be iimited to, piacing the ma- teriais on opposite sides of the trench. 8. Water Removal 1. During excavation and pipe installation, the Con- tractor shaii remove by pumping or other approved means, ail water which is detrimental to the installation of the sewage disposal system. 3.04 PIPE INSTALLATION (OTHER THAN DRAINFIELD) A. All pipe shall be laid in a 6" deep bed of classified material with no stones larger than 2", unless the Owner's Representative determines that the existing trench bottom is suitable for bedding. All bedding material shall extend up to the spring line of pipe. Bedding material shall be compacted to 95 percent maximum density. B. Pipe laying shall in all cases proceed upgrade with the spigot ends of the pipe pointing in the direction of the fiow. Each pipe shaii be laid true to iine and grade and in such a manner as to form a close concen- tric joint with the adjoining pipe. The alignment of the installed pipe shall appear straight to the naked eye and shall be such that a full circle of light can be seen between manholes, etc., when sighting along all points of the pipe circumference. Each section of pipe shell be handled carefully and placed accurately; the spigot end shall be fully inserted. Care shall be 02743-8 exercised to avoid over-insertion. Each section of pipe shall be properiy supported to ensure true align- ment and an invert which is smooth and free from roughness or irregularity. C. At all times, when work is not in progress, open ends of pipe and fittings shaiI be securely and satisfac- toriiy ciosed so that no undesirabie substances wiii enter the pipe or fittings. D. Laying Instructions for Pipe 1. All pipe shali be laid in accordance with the re- spective manufacturer's recommendations. 2. No pipe shall be laid when the bottom of the ditch or the sides to one foot above the pipe is frozen. No backfill containing frozen material shall be placed within three feet of the pipe, nor shall the trench be left open during freezing weather so that temperature of the material near the pipe goes beiow freezing. 3.05 SEPTIC TANK A. After excavation the tank shall be placed on undis- turbed soii on a Ievei grade at a depth as indicated on the drawings. BackfiiI around the tank shaii be done in 12" iifts with cIassified fili and compacted to 95 percent maximum density. Any damage to the pro- tective costing during instaiiation shaii be repaired at no expense to the Owner. B. The tank inlet shali be set at the elevation shown on the drawings. Care shall be taken during installation to ensure the proper elevation drop between the inlet and the outlet. C. The tank shall be filled with water during backfilling to prevent flotation. 3.06 DRAINFIELD A. The drainfield area shall be excavated and backfilled to the elevation and dimensions as shown on the draw- ing. After excavation the open trench shall be pro- tected from surface runoff to prevent the entrance of silt and debris. All smeared or compacted surfaces shall be raked to a depth of 1 inch, and loose ma- terial removed, before any gravel is placed. 02743-9 The trench shall be covered with 1/2" - 2 1/2" olean gravel or crushed rock extending at least two inches above and six inches below the drsinField pipe, or as shown on the drawings. The bottom of the trench and the drainfield pipe should be as level as practical, with a maximum grade of 0.25 percent awsy from the distribution header. Pipe jointing shali be accomplished the manufacturer's recommendation to lied on the drawing. in accordance with the length speci- The distribution lines shall be spaced as shown on the drawings. The gravel or crushed rock shall be covered with filter fabric, to maintain separation between the gravel and backfill. The drainfield shall then be backfilled with unciassi- lied fill to the elevation shown. The trench shall be slightly overfilled to allow for settlement. Backfill of drainfield shall not be compacted. MANHOLE CONSTRUCTION The manhole rings and covers shall be brought to the grades shown on the Pians. Manhoie rings shai1 be set in a fuiI bed of mortar and made secure. Ali portions of precast manhoies must be approved prior to instaiiation in the sewage disposaI system. The pr.cast manhoIe manufacturer shaIi provide timeiy notice (at ieast two working days in advance) to allow time for the Owner's Representative to arrange for necessary inspectioO. This approval does not relieve the Contractor of the responsiSiiity for protection of manhoies against damaged during handIing and instailation, Manholes shall be installed at the locations shown on the plans such that primary leads enter radially at the invert elevations specified. The base section shall be set plumb on a level subgrade~ compacted to 95,"6 maximum density. 02743-10 De In the case of poured-in-place manhole construction, if the Contractor elects to accomplish the manhole construction utilizing more than one continuous con- crete 'pour, a keyed construction joint shall be used. These manholes shall have poured-in-piece bases. 3.08 TEST OF WORKMANSHIP A. General 1. All sanitary sewer lines constructed between the building and septic tank shall be subjected to a leakage test and proven tight within the tolerances specified herein. All labor, equipment, and supervision required for this work shall be furnished by the Contractor at his expense, and shall be considered incidental to the other pay items and will not be paid for separately. B. Exfiltration Test (Using Water) 1. On completion of a section of sanitary sewer between manholes or otherwise, the ends of all pipe shall be plugged, including service connections. All testing shall be conducted after backfilling, prior to resurfacing, and after service connections are made. The lengths of service connections shall be included in the computations to determine the allowable leakage for the test section. 2. A minimum head of six (6) feet of water above the crown at the upper end of the test section shall be maintained for a period of four (4) hours during which time it will be presumed that full absorption of the pipe body has taken place and thereafter for a further period of one (1) hour for the actual test of leakage. During this one-hour period the measured loss shall not exceed the rate given in the following formula: E : O.O04DL E : Allowable leakage in gallons per hour D : Nominal inside diameter of pipe in inches L = Length of pipe being tested in feet Exfiltration in greater amounts than shown in the table will be cause for rejection of the sanitary sewer and all repairs necessary to meet these requirements and/or ret.sting will be at the expense of the Contractor. 0274~-11 4. If it is not apparent that leakage between the building connection and the septic tank was probably satisfactory, then the Owner's Representa- tive may require subsequent tests to establish the more exact location of the leakage area. Any sec- tion of sanitary sewer that does not meet the above requirements shall be rejected and the Contractor, at his own expense~ shall make necessary repairs to the sanltary sewer to meet the requirements~ and shall make subsequent tests after repairs to assure compliance with the specifications. C. Exfiltration Test (Using Air) 1. The Contractor shall furnish all facilities and personnel for conducting the test under the obser- vation of the Owner's Representative. The equip- ment and personnel shall be subject to the approval of the Owner's Representstive. 2. The Contractor may desire to make an air test prior to backfilling for his own purpose. However, the acceptance air test shall be made after backfilling has been completed and compacted. 3. Immediately following the pipe cleaning, the pipe installation shall be tested with low-pressure air. Air shall be slowly supplied to the plugged pipe installation until the internal air pressure reached 4.0 pounds per square inch greater than the average back pressure of any groundwater that may submerge the pipe. At least two (2) minutes shall be allowed for temperature stabilization before proceeding further. fl. The pipeline shall be considered acceptable when tested at an average pressure of 4.0 pounds per square inch greater than the average back pressure of any groundwater that may submerge the pipe, if the total rate of air loss from any section tested in its entirety between manholes or between man- holes and cleanout structures does not exceed 2.0 cubic feet per minute, or the following table may be utilized as a guideline for a satisfactory test by air for pipe sizes shown: Pipe Diameter Allowable Pressure Drop in 10 Minutes 6" 2.7 psi 8" 2.7 psi 5. Pressure gauges shall be incremented in not more than 1/2 pound increments for sccurste tests. 02743-12 6. If the pipe installation fails to meet test requirements, the Contractor shall determine at his own expense the source or sources of leakage, and he shall repair (if the extent and type of repairs proposed by the Contractor appear reasonable to the Owner's Representative) or replace all defective materials or workmanship. The completed pipe installation shall meet the requirements of this test or the alternative water exfiltration test before being considered acceptable. 7. SAFETY braces shall be required to hold plugs in place and to prevent the sudden release of the com- pressed air. Due to the large forces that could be exerted by an escaping plug during the testing of the pipe, no workman shall be allowed in the man- holes in which plugs have been pla.ced while tests are being conducted. Also the Contractor's testing equipment shall be arranged in such a manner that a pressure relief device will prohibit the pressure in the pipeline from exceeding 10 psi. 3.09 EXISTING UTILITIES A. The Contractor is responsible for the protection of all existing underground, surface or overhead utili- ties end for the protection of adjacent structures. Plan locations of existing underground facilities are to be considered approximate only and shall be veri- fied with the owning utility by the Contractor. The methods used to protect existing utilities, appurten- ances, structures, etc., shall be subject of the approvaI of the Owning Agency. B. Contractor shall verify location of and elevations to existing sewers that new lines tie into prior to con- struction. C. New sewer lines must not cross existing water lines with less than 18" clearance. Contractor shall verify existing water line elevations and notify Owner's Representative immediately of any conflicts, prior to laying the new lines. 3.10 TRENCH BACKFILL. A. General 1. After the lines have been inspect'ed and prior to testing~ the trenches shall be backfilled. 2. Unsuitable or surplus excavated materials shall be removed from the area. Contractor shall furnish additional unclassified or classified backfill materials, if required, from offsite sources. 02743-13 B. Backfill 1. Bsckfill from the top of the bedding to one foot above top of pipe shall be with originsl unclassi- fied material, if available, otherwise the Contrac- tor shall bring in unclassified material from other sources. Material shall be 2 inches maximum size, free from frozen clods. The Contractor shall care- fully place and thoroughly compact around and above pipe to minimum 90 percent density. The remainder of the backfill shall be original material, com- pacted to 90 percent maximum density, provided it is free of all extraneous material such as organic material, trees, brush, trash and large boulders. Additional backfill, if required, may be unclassi- fied material. 2. The Contractor shall restore surface to its origi- nal contour and elevation, or in areas of new grading to the new design grade. 3.11 AS-BUILTS Ae Adequate standard construction notes relating to the line and grade shaii be kept by the Contractor's sur- veyor and shaii be submitted to the Owner's Represen- tative prior to appiication for final payment. These notes shaiI show date and surveyor's name and shaiI inciude, but not be iimited to, the horizontai and verticai iocation of aii utilities or other permanent structures intercepted or encountered in trench exca- vation, station of aii changes in pipe type or ciass, repairs and type of repair. Construction notes shai1 be reduced to show actuai elevation of inverts. In addition, the Contractor shall submit a copy of the drawings, marked in red to show any deviations from the plans. It shall also show the station at the main and two or more swing ties from prominent permanent features to show the location of each service connec- tion. Swing ties shall be as close to 90 degrees to each other as possible. It shall also show ties to property corners. C. If adequate as-built data is not provided as defined above, the Owner may perform an as-built survey and deduct the cost from monies due the Contractor. ~ 3.12 EXISTING SEWAGE FLOWS A. The Contractor shall be responsible for handling of existing sewage fiows where project work requires modifications, reconstruction, connections, etc., to existing sewer systems. Methods shaii inciude by- passes, enciosures, seais, pumping, and other tempor- ary faeiIities to safeiy handie existing sewage flows. 3.13 CLEANUP A. General 1. During the time that the work is in progress, the Contractor shall make every effort to maintain the premises in a neat and orderly condition. All refuse, broken pipe, excess fili materiai, cribbing, etc., shaiI be removed as soon as prac- ticabie. 2. Shouid the cieanup not be maintained in a prudent manner, the Owner's Representative may cause the work to stop and payments to be withheId untii the "cIeanup" portion of the work has been done to the satisfaction of the Owner's Representative. B. Sanitary Sewers 1. The Contractor shall flush and clean all sanitary sewers. All sand, debris mortar and foreign ma- terial shall be removed from the sanitary sewers, and manholes, septic tank, and drain pipes. 3.14 MEASUREMENT AND PAYMENT A. The extent of sewer utility work is shown on the drawings and no measurement for pay quantities shall be made. B. Payment wili be made at the bid lump sum price. It will be full compensation for furnishing and installing the on-site sewage disposai system as shown on the drawings and specified herein, including excavation, backfill, bedding material, compaction, testing, connections to existing lines and as-builts. C. Payment will be made under: Item Pay Unit On-Site Sewage Disposal System Lump Sum 02743-15 June 24, 1985 Coffman Engineers, Inc. ~UNICJPALITY OF ANCHORAGE DEPT. OF HEALTH & ENVIRONMENTAL PROTECTION JUN 2 4 1,985 .RECEIVED Mr. Robby W. Robinson Municipality of Anchorage Environmental Health Division 825 "L" Street Anchorage, Alaska 99501 SUBJECT: CHUGIAK HIGH SCHOOL ADDITION AND RENOVATION PROJECT Dear Mr. Robinson: This letter is in response to your comments to Mimi Meiser, Community Planning Department, May 21, 1985. Comments I and 2: The Anchorage School District is proposing to expand Chugiak High School with the addition of a new library, administration area, and 19 classrooms. This will increase the capacity of the school from the current 1500 students to a projected enrollment of 1800 students. We are proposing to construct a new on-site sewage disposal system in the fall of 1985. Transmitted herewith are the preliminary construction documents for the on-site sewage disposal system for your review and comment. These documents have been transmitted to the Alaska Department of Environmental Conservation for their review and permitting. Their comments will be forwarded to your office upon receipt. The construction of the new wing will require excavation into the area of the existing leachfield. This system was made operational about 1963. We would appreciate your comments and recommendations as to the proper handling of excavated materials in this location. 550 W. Seventh Avenue, Suite 700 / Anchorage, Alaska 99501 / Phone (907) 276-9664 1021 - 112~h Avert ue N.E. / Berlevue, Washington 98004 / Phone (206) 453 8092 4145 N.E. Cully Boulevard / Podland, Oregon 97218 / Phone (503) 282 314 t Mr. Robby W. Robinson Municipality of Anchorage June 24, 1985 Page 2 Comment 3: The Architect is preparing documents for the expansion of the cafeteria/kitchen area. The Architect will be submitting preliminary plans to your office for review at a future date. pl-ase contact me if you have any questions. Sincerely, COFFMAN ENGINEERS, INC. 8eott Mohr Pro~eet Manager Attachment 69L1/pw C. William Echols, Jr., ASD Richard Arndt, ASD Dan Farr, TRA/Farr Richard T. Lundgren, CEI 84117-02 DATE: TO: FROM: SUBJECT: J unicipality of Anchor ¢ MEMORANDUM May 21, 1985 MiMi Meiser, Community Plan Department Manager, Environmental Health Divisionz~z~- Chugach High School Addition and Renovation Project 1. There is nothing in the material recieved by the EHD which indicates any changes to the student load/staff load or any additional facility load. Also, there is nothing in the material recieved by the EHD which indicates any addi- tions or modifications to the existing on-site wastewater disposal system. 2. In checking with Mr. Steve Eng with the Alaska Department of Environmental Conservation, we are informed that they (AJ]EC) have not recieved any plans, drawings, specs or other information or the Chugiak High School Additions & Renevatiens. The ADEC comments must be obtained and reviewed by this office. 3. Sheet No A-3R indicates there will be some alterations/renovations to the CAFERTERIA/KITCHEN area. There must be plans submetted to EHD indicating in complete detail any modifications/additions to the existing facilities. These plans must then be reviewed and approved by EHD proir to the commencement of any c ons/~ion. Robby W. Robinson, Manager Environmental Health Division RWR1/srm OLYMPIC FOUNDRY COMPANY QUALITY CASTINGS SINCE 1900 O. L "JACK" MARSHALL VICE pRESIDENT OF SALES 5200 AIRPORT WAY $E.ATTLE, WA 9810~ (206) 764-6200 'SETTING end OPERAT XlG .INSTRtJCT O'N$ MILLER STANDARD SE¥TAGE S PHON$ BULLETIN 1~5A OLYMPIC FOUNDRY COMPANY .. 5200 AIRPORT WAY SO. ., sEATTL~ WASH. 981e8 . Sinsl Sip non inst 11 tion It ns important that lhe siphon be installed in accordance with the pla.".s furnish-~d and all dimens~$ns and elevations should be carefully iai!owed. No chanCss should be made v,,~:hout ~rst comm~nEcat~n~ wE~h First se: the main trap ~n the concrete, being sure that it is plumb and that the long leg pro- jects the correct dis:since above the ~oor al the dos~ag ta~k a5 sho'~'a on tee Next-screw auxiliary-vent 'piping into the bell. TEe joi~:s shoul~ be ~'eY leaded and screwed .up to insure a~ a~-t~ght jo~. Next pl!ce the bell over the lon~ leg of the trap. gffpporting ihe bell on the lug~ cag~ in the bell. Fill-the ~ain tr~p w~th w~ter. How it Opzratcs ']'he action of the .Mi~er S!.~a,~ is as foHows:~ As the sewage entering the ~ank rises above the end of tee auxiliary vent (3" Fad 4'[ single siphons :d shipped prlor to Septer6,ber, 1937 have a vent cast in the bell which serves the same purpose) · in the bell it encloses the air within, 'the lower portion of the trap being, o[ course, filled with water. As the sewage level in the tank rises tb.e confined air gradually forces the water out of the long leg al the trap. unti! a point is reached ~vhen tee air just endeavors to escope around the' lower bend. l~ow as the difference el water level i~ the two legs of the trap equa)s tee diffler~:nce of the levels, bets:teen the sewage in the tank and the · sewage within the hell. it will be seen that the ~o)umn o[ se;,-'a~e in the short dis}'harz, e leg bas'. ' practically the 'same depth as the head of water in the tanld above the level at which it stand,. in the bell. 'Tile two columns bl water thereIore' counterbalance each other at a certain £~xed depth in the tank· As soon as this depth is increased b~ a further snpply, hoxvever small, a portion ol the confined air is forced around the lower bend. and by its-upwa, rd rush carries with it same o[ the water in the short leg, thus upsettin~ the equlhb- rium and the siphon is brought into full action immediately. The .,,ewage is then drawn out of the tank to the bottom of the bell. the siphon is star, pod by drawing air nndcr the bell. ami complete'fy vented by the admission of air thro,lilh the auxiliary vent anti the operation repeated. P.~ge Two II ~"l~,a~e~'~ ~.~r'Z=';~£~ -~ ,,°~ · . - '~ ": I ~ ..... -., '4 '. When th~ water has ~lled the dosing tank to a point which covers the bell and the piping con- nect~ons, a c]os~ observation of the water ~ur~acc should bc madt to d~t~ct any bubbles r.iaing to the surface which woul8 indicate an air leak. If any are tound, e~th~r in the piping or bell casting, they should ~ 6x~. ..~ The discharge Ene I~ading from thc siphon to the tile field or filter bed mu~t have a slight {alt or pitch away from the siphon. This is neces~a~ in order to prevent backing up and causing sewage to stand over and submerge ret projtctlon of the short leg oI the trap in the discharge head. The discharge llne from the siphon should b~ vented back into the dosing tank as shown· Double Alternat]n Siphons Installation First set the two'ma[n traps in concrete, be]n[ sure that they are plumb and that the lon[ le~s project the same distance above the floor os shown 'Next screw auxiliary vent pipin[ in the hells. The joints should be w~]l leaded end screwed up to insure an air-al[hr job. Next place the. bells over the 1on~ le~ of the traps, supportinE the bells on the lu[s test in the b~lls. - To Start S;ph s fill tb~ main traps of both siphons with water. A,'e ! Operation The main traps having been filled, the water levels will be at A in both traps. See Figure I. The inflow is then turned on .a, nd the dosing tank allowed to fill. When the wa,er level in the tank reaches the end of the auxi!iary vent pipe at X the air within the siphons is confined and put under pressure which gradually increases as the water in the tank rises, This pressure forces the water in the long legs of both traps down and when the discharge line in the tank is reached the levels'in the main traps will be at A ~nd Al. Figure 2. At this point the actual press,ire within t~h.e siphon is equal lo the depth of the main trap, he action at this point is the same as described . der single siphons. If both siphons ~were con- -~tructed and set perfectly they would both be "'~':,?:.1~; : - Page .... - . .~i~ ..,..~... ,, R1 'hr variation in the conMruction or ciera[tons ~Jl,.~l/Jt ~.~ -- ~, , ,~'~-~. .~rg-~ of setting wall.be, ~u~oent to brm~ one ssphon On the Rrst operatmn the ~p~on wall o~s~ar~ ~' ' . ~. · , ' , . -' ; .... ~ . ~. When the oells and aux~hary vents are covere4"~Y ' ' P · PP ..... w~th wa.er a close observation of th~ r. ur[-~ce~'; :, charge, and subsequent dlscha.ge~ wtu ta~e ~lac< ' should be made to detect any bubbles r~sing tO'~'~'~. ur. der somewhat diEerent con,'.i'ior, s. It Was stated that the pressure forced the water in the Ior. g legs down to points A and At. It will now be s~.en that as siphon No. I e~ptles the tank. the pressur~ on siphon ?~o. 2 (or idle siphon) is relgase~ and when the end of the auxiliary ven~ X is reached, atmospheric pressur~ is restored in that siphon. This release oI pressure permits the water level in the short leg of siphon No. 2 to [aH back to a natural level Ss: abode half of the watar had been lorced out of the trap on the upward rise and therelore when it Ial!s back the levels in tee idle trap will be at B, Figure 3. Siphon ~o. I having just operaled will be left with a full trap. It will now be noted that there is a greater quautitx of air trappe~ in the long leg of one siphon. Due to this exlra air a bubble wilt'be force~ around the bend in the ~ pnon first thus causing th~..Otterh~ing operatiom ~ : ::-:--- --- :-- On the third filling the conditions will be re- versed and No. 1 wHi have the excess air. No connecting piping or other ~evices are re- the surface which would indicate an air leak· any are found either in the piping or bell casting they should be fixed, as the siphons will ol:erate rc~erl' ~! there is a leak '" If there are no lea~<s and ~he slphons still d~'~.~; not alternate; it wlU be found the idle trap'is're:~. Riled in some way when the other siphon This cou!d take place through a ]ea~ in the R~r where the outlet pipe is joined to t~e discharge head of the siphon trap. or sometimes t~e tw~:~ s~phons are discharged into a slngle manho:e ~-"~' ~ore diverting to the beds. This would per.it ~h~ discharge from one siphon backing up and lng the tr~p o{ the ~dle s~phon. Do no~ use ~h~s In order to determlne whether the idle trap has' been refilled, remove both bells and down lr°m the top o[ the I~g le~ o[ water in *he traps. The difference· in the two traps should be as shown in the illustralion at the bottom of page 3. quired to bring about ~his alternating feature and . A continuous., tight, line should be.run, from each ~t. . ~, if the siphons are set exactly in accordance with s~phon to ~,s bed. w~th proper proves,on for vent-~-Lj?' our drawing, no trouble should be experienced, lng these lines as previously noted. . - :,~::: It frequently happens that'a system o~"sewers is not available in which to empty the se~vage from residences, farm dwellings, clubs, ins,itu'- tions, etc.. and under such circumstances it is meat plant which will conveniently and satisfac- torily produce an effluent which when discharged nuisance. Ordinarily the design of plants far the treatment of sewage involves an engineering prob- lem which should be handled by some one familiar with the best practice in that field, but for the small installations now under consideration, the employment of an Engineer to make plans, speci- fications, etc.. is generally eliminated on account of the cost· However, a plant of this kind should be designed and constructed with regard to prac- tices which have been Iound'satlsfactory in years of use. A great many states have reguflatlons governing the design and construction of sewage treatment plants. We do not design nor furnish plans for work of this kind. but descriptive bulletins can be obtained from most of the State Boards o[ Health, the United States ]Department of Agriculture and the United-~tates Public Healt. h Service. _~There are also several reliable companies who make a business of furnishing complete plans and speci- fications and some of the materials required in the Owing to the conditions under which this type of plant generally operates, it is desirable that the results sought be obtained with the least possible complications and at'a minimum cost. Many years of experience indicate that when conditions are favorable the sc-called sub-soll irrigation type of installation is probably the best method. It is economical, efficient and requires the least amount o,e attention. Regardless of whether the sub-soil irrlgation'.method is used -for a secondary treat- ment or whether a small filter bed is constructed. it is necessary to provide some preliminary form of treatment, such as a settling or septic tank." The sewage from the house is delivered into the settling tank, wbirh should be of pFoper size and design, the purpose of the tank being to permit the settling out of the solid matters contained in the sewage, and every tank design should provide baffles or other means for preventing the solids from leav!ng the settling tank· The liquid should pass on to a second compart- ment that is called a dosing tank, and in thiR tank there should be locat~.d a MILLER SIPHO}',~ of proper size and·drawing depth to intermittently discharge the contents of the dosing tank into the sub-soll tile or whatever secondary type of treat- ment is used. It is not desirable to permit the sewage to ilo:,-' directly from the settli.".~ tank to the sub-soil tile2 If it. does. the fiherin~ material surrounding the tile will be constantly saturated in places and eventually '.viii become clogged and foul. The inter:-nittent discharge permits the filter- ing materials' to rest after ,each application o! sewage and thus prolongs the usefulness and efficiency of the system. . . The discharge from a dosing tank also com- pletety fills the sub-soll tile, thus insuring that every part o[ ~the irrigation field will receive its quota of sewage. · The results outlined and which are quite essen- tial to the proper operation of the plan{ are best obtained by using one of our STANDARD SEx, V- AGE SIPHONS as illustra, ted on p~ge 3. These siphons are made in several sizes. The drawing depths shown in the tables are standard ~nd can- not be ~ncreased, they can, however, be reduced .within cer ta!_n_limits. The size and drawing d~pth'gf th;'~h~-~e-© leered will depend upon the fall available and the. amount of sewage to be treated. We recomme.~. Sizes as follows for plants serving: - 5 to 15 persons, use 3-inch siphon. 16 to 40 persons, use 4-inch siphon. 41 to l~0persons, use 5-inch siphon. I01 to 200 persons, use 6-inch siphon. The cut on page 4 shows a suggested arrange- ment for a small plant, and we call attention to the vent leading from the discharge pipe back into the dosing tank at a point above the siphon dis- charge line. This vent should not be omLtted it is quite necessary to the proper operation of the siphon. -The same results can be obtained by setting the s~pEon farther back in the dosing tank. p!aclng fi tee at the discharge head and rhea rais- ing a straight piece of pipe up from the tee outlet~ inside the dosing tank to a point 3 inches or 4 inches above tee discharge line. The 3", 4", 5". 6" Standard Design Single Sewage Siphons t -I Approximate Dimensions in Inches and .Average Weights in Pounds Diameter of Siphon ...................... · *- - Drawing Depth .................. Diameter of Discharge Head .............. Diameter el' Bell ......................... Invert Below Floor ...................... Depth o[ Trap ........................... Width of Trap ..... ' ...................... Height Above Floor ...................... Invert to Discharge = D-r- E + K .......... ~ottom Of l~el] to Floor ................. Center o! Trap to End of Discharge Ell. s~. Diameter of Carrier ..................... Average Discharge Rate G.P.M ....... I, laxirnum Discharge Rate G.P.M .......... Minimum Discharge Rat.- G.P.~! .......... Pounds ........ Drawing l-F ...................... J 13 · 6O $ 23 6 15 6 30 8 19 10 301~ 16 11 44 4 17 g-10 474 604 340 300 376 o single Siphvns oi th~s type set s de by side in the same tank will alternate. See Bulletin el2$A for descrip- tion o~ operation. The draJt 'ri)" will be 1" to 2" less in this case. Siphons listed here are i:arrled in stock by us and can shipped prompt :,- on receipt of order. U U ~ U¸U Z Z i. :I SNOIZVAON'::II::I 9 SNOLLIaaV ~OOHO$ HDIH NVIDNHOJ NY'Id DNII N¥'ld /. '\ Y 3Nl~43rc¢~ ,.~o,~.~a ~oo.o. ~.~o...vI eN'Pu.V^ON-~'d V eNOLLIclavl ' 8NOiJ. VAg"I3 'ElOlag~Xg ~ sNoI.LVAON3IH '~ SNOI,.LI{313V 'IOOHO8 HE)IH 'N¥1iOnHOI -I NV'Id EIE].LSVIAt MUNICIPALITY OF ANCHORAGE DEPARTMENT OF HEALTH & ENVIRONMENTAL PROTECTION Environmental Health Division /__ CASE REVIEW WORKSHEET ~ CASE NUMBER: DATE RECEIVED: COMMENTS DUE BY: S-8136 April 25, 1985 May 17, 1985 SUBDIVISION OR PROJECT TITLE: Tract A Chugiak School Subdivision ( ) PUBLIC WATER AVAILABLE ( ) PUBLIC SEWER AVAILABLE ( ) COMMUNITY WATER AVAILABLE 7%014 (Rev. 5/83) TEST BORING 9a ~ 28~ 28 b o PERCENT FINER BY WEIGHT PERCENT CO~RSF-R ~Y W~I~HT PERCENT FINE~ BY WEIGHT III IIIII IIIIIIIIrt Illll Ill Ilill IIIIIIIIIIIIIII rllll : Illllil Illil IIIIlilllilllll lilL, F IIIIIIIII '11IIIllllllltilll -H111 IIItllli ii IIIlilllllllll.P IIIII ill fill irllr IIiiiiii1~11 iiiii iiiii IIIII IIIIIJ. kflllllll IIIII H IIIII IIIlil~lll~llllIIIII IIIII IIIIIIIIIIIIIIII1111 I ~ I illll tllllllllllllllIt111 illlll~'llllilll IIIIIlillllLIII IIIII 111111411i t1111 1-1111111111111 IIIII IIII1~1tll illll IIIIIIIIIIIII Illil I IIIIlll;l Iiili lllil;;;iiiiill lllll IlllllllI tllilllllllllll IIIII lllll Illll IIIIIIIIIIIIIII IIIli Illlllllll IIIII IIIIIIIIIIHIII illll illillllll IIII 111111111411111 IIIII IIIlililll III IIIIIIIIIIIlill IIIli II I lilt