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HomeMy WebLinkAboutWWP2700510 KAP-27-0510 =t TCM LIFT S=CN REPLACE!U - Prelim. Design & PlM. 1 r � r i BEGINNING OF FILE FILL TIT« WW Rai -olio CoTnNWOOb JJ PR6" M IN RY PlANN/NrG I76slGN { {. W f i` ICYN— ♦-9m rmu 10 tee. WFl D� V` P10D Or 1Tr (W WAo eN TC^ DEPARTMENT OF ECOLOGY r' hue Step ►V-11 a 01y^W. 9laatirytlWi uYA11-,1>it . ix,nJ ar.6(XIU t s - January 2, 1990 IMr. Ronald L. Olsen Utility Engineering City of Renton Public Works Departacnt ' f 200 Hill Avenue South ]+ Renton, WA 98055 Re: city of Renton Storm Sewer Rehabilitation for Wall Field Protection. Dear Mr. Olsen; _ It,ank you for submitting the City of Renton's P:ellninary Study of Storm Sewer Rehabilitation fox Wall Field Protection. p I hw a reviewed the Preliminary Study of Store. Sewer Rehabilitation for Well Field Protection, taking It as an EngLnesrinS Report I have found a number of deficiencies that have to be addressed as per the enclosed ., Ecology Review Criteria for Englnserirg Report Type Documents for Hon-Point Projects (supplied to you previously). j Ad'itionally, I have several questions and ecmments that must be a:r, c . •d in your revised Engineering Report prior to approval: 1. FLsass include any availaule evidence of aquifer contaminacion dus °. to deteriorated storm drains. 1 2. Devine the aquifer - wet and dry wearher flow directions, draw-offs, oqu_potentlei lines - present appropriate hydrdingica: documentation, Sep$ etc. 3. Present evidence that the storm drains are deteriorated. i 4. When are Improvements to 1.405 planned to be made in the vicinity of the Aquifer? 5. IFe iquifer Protection PIa1 sap fF1,ura + -^readable. Please submit a better copy. b. Demonstrate that rehabilitated lines will have adequate flow _ capacity. _ ? 1984 CH2M Hill's Well Field protection Study recommended severe. measured to protect aquifer (page xt and ollowing). Has the City tmplemented those? -a ka�+ t L @ » JAM- ♦-9e TMU 10 %26 WA DOE MOD W_ ea } Mr. Ronald L. Olsen , i January 2, 1990 Page 2 i I hope you will have enough time to address those above listed require- ments. If you have any questions please call at at (206) 438-7749. Pincerely, // M`rcel Szyszkovski G Projicc Engineer Enginetring Management Section 'dater Quality Financial Assistance Enclosure cc: Janet Boyd, Ecology/Grants Guy Anderson, Ecology/b'WRO i I 3 r NIMM WATER QUALITY FINANCIAL ASSISTANCE Review Criteria for Engineering Report Type r M Documents for Nan-Point Projects E C O L O G 1' June 16,1999 The required contents of an Engineering Report are described in Chapter 173-240 WAC While this chapter was written with a focus on sewage disposal; the type of information required and the Department's review process will apply for construction of projects to control nonpoint sources o;pollution.For Lake Restoration projects,study requirements are defined in 40 CFR 35 Subpart H. An engineering type report submitted in support cf construction of a nonpoint F-"uion control pro,,ect must be sufficiently complete so that plans and specification can be developed from it.Although the Department—my request further information,the follow- ing describes the basic information which the document shall contain. 1. General Information a. Project d.xription Include a description of the water quality problem whirl, this project will solve or prevent. • Identify applicable state,federal or local water quality regulations with which this project must comply. b. Project proponent • Agency name,purpose,area of service or expertise,organization,staffing • Agency's experience in mamging construction projects and or operating water quality facilities c. Project Location - • Include a idchuty and site map to make the project's location clear to the reviewer • Dkcuss the suitability of the proposed site d. Financing • Describe how the project will be fundea. Include a discussion n t only of capital costs, but also funding for operation, maintenance and replacement costs. e. Operations • Explain who will own operate,and maintain the project after completion of construction. Discuss ar,y inletlocal or operating agreements needed. I. Proposed schedule for final design and construction • Describe any timing constraints, such as HPA limits. r, !4 ea, K! Z• t•ngineering infomtation to include: • Basic design data and suing calcolatiors of thtr oroposed facility • Layout sketches of the project • Process and operation description which Includes flow diagrams • Discuss expected levels of water quality improvement as a . suit of tlus Project. • If project will be affa;ed by stormwater flows, describe the design flow the facility wiLl accomm,ndate, and any feat,ares needed, such as bass, to i prevent failure. yp • Operation and mainnmance considerations, inc!udwg emergency operations, m prvvisions for oil and hazardous aterial spill control and/or accidental discharge prevention • Disposal of any collected sediment,or other solid, semisolid or Squid wastes resulting from project operation • Discussion of the suitability of the proposed site for the facility 3. Alternatives: • Discuss the various alternatives considered and how thry were evaluated. iuclude the considerations for sehction of the preferred alternative, such a.� er,•.:ronmental impacts, cost effectiveness, public acceptance, operation - maintenance concerns,atc. • Discuss any public review or involvemelt prc.=ss which has been caut'.- in developing this project. • Describe how this project fib ir.o any long range water quality improver, -plans. 4- Supplemental information: a. Engineeringlustiftcation • Describe any reports, pilot plant data, operations of similar installatio.s, scientific data,or other engineering justification available which sup- Judgment that the proposed project will operate a; ablerequ to produce ti:e desired water quality improvement. b. Evidence of compliance with the State Environmental Policy Act and/or the National Environmental Policy Act c. Copies of any discharge permib and compliance orders which relate to this project d. Statements regarding compliance with any state or loaf water quality management plan or any such plan adopted pursuant to the Federal Water Pollution Control Act as amended e. A proposal for monitoring to document that the project meets its design purpase S. Any additional information deemed necessaryby,heDepartment i y, yd k? , 1 ` 111 1 1 sy S 4 y li y .dtR e f f 1� 1; 1 e CITY OF RENTON COTTONWOOD LIFT STATION PRE-DESIGN REPORT J NOVEMBER 1991 1 1 i 1 RH2 Engineering, P.S. 8383 158th Ave NE Suite 200 1 Redmond, Washington 98052 } (206) 869-1488 1 1 Y f CITY OF RENTON COTTONWOOD LIFT STATION PRE-DESIGN REPORT REVISED NOVEMBER 1991 INTRODUCTION d This report presents RH2 Engineering's investigation of the existing condition of the Cottonwood Lift Station and recommends three replacement alternatives that will ensure compliance with the City's "Underground Storage Tank Secondary Containment Ordinance" (Ordinance No. 4147). This report also contains a budget and project schedule. BACKGROUND t li �i _i C.i• :a - Current Standards The "Underground Storage Tank Secondary Containment Ordinance", (Ordinance No. 4147) passed in April 1988, ehtablished secondary containment and monitoring y requirements for new and existing underground storage facilities which store toxic .J substances. The intent of the ordinance is to protect the City's groundwater resources. Sectioi.7-1204,paragraph P of Ordinance 4147 defines a toxic substance as any material "...which may pose a present or potential hazard to human health or to the quality of groundwaterr...". This ordinance also defines an underground storage y facility as "a tank, pipe, vessel or other container...used for the underground storage...of regulated substances..:'. Toxic substances are one of the defined categories of regulated substanc"s. Section 7-1206 paragraph C states: 1 J All eai-,ting underground storage facilities which are located in Zone I of the Aquifer Protection Area and which store regulated substances must comply with the construction and monitoring - -' standards for new underground storage facilities as set forth in this ordinance within eighteen (18) months of the date of adoption of ` this Section." e The Cottonwood Lift Station hes within Zane I of the Aquifer Protection Area(APA)(see ' attached map) and can be clearly defined as an underground storage facility used to store a regulated substance. Compliance with Ordinance 4147 requires that minimal improvements to the lift station include an acceptable secondary containment vessel for the wet well and an approved monitoring system. i 1 uxw[n�xr�corvens,;� i YI •_ l� I _ r 771 I )! Cottonwood Lift Station ' ! _ Pre-Design Report 1983 Comprehensive Plan The recent adoption of Ordinance No.4147 has resulted in a reassessment of the priority of projects in the Capital Improvement Program. The 1983 Comprehensive Sewer Plan prepared by Wilsey and Ham identifies the need for rehabilitation of the Cottonwood Lift Station in the proposed Capital Improvement Program, In a memorandum dated j February 24. 1989 from Mr.Jack Crumley to Mr. Don Monaghan,the Cottonwood Lift f Station was listed as the highest priority for lift station replacement. { Location -+ The Cottonwood Litt Station is located on the south side of the Maple Valley Highway between Stoneway Concrete and the Riviera Apartments. FIGURE 1 shows the location of the lift station and its relation to Zone 1 of the APA and the location of the City's potable water wells. d Water Contamination A force main or wet well break of the Cottonwood Lift Station will result in bacteriological contamination of Well Nos. 1R, 2R, 3R, 3, 8 and 9. Consequently, determining the Structural integrity of the wet well and force main are essentia' maintaining Renton's water quality. A recent side sewer break near Stoneway Concrete resulted in bacteriological contamination in all of these wells. TABLE 6-4 in the City's Comprehensive Plan shows these contaminations. In addition, the lift station force main ruptured two years ago. The extent of contamination from this event is not known because no test was performed at the time. The rupture was repaired with a steel band. Another failure will result in contaminated groundwater, Senice Area The existing service area of the Cottonwood Lift Station includes the Riviera Apartments (approximately 250 units) adjacent to the Cedar River, the Riviera Tavern, a small grocery and a large recreation hall. The existing service area is at full development. Flow Capacity TIa apartment complex, recreation hall, tavern, and grocery store are the only "1 contributing sources of raw sewage. The existing flow rates were estimated by assuming J full occupancy of the 250-unit apartment complex, a 500•person capacity for the recreation hall, and a negligible contribution from the grocery store and tavern. To determine infiltration/inflow, the service area was approximated to be 12 acres. Using -� a peak value of 210 GPD per capita,3.4 people per apartment,this translates to a now of 178,500 GPD or 124 gpm. Using a peak flow of 30 GPD per capita,the flow from the J 2 w:nv,ucwt�corenm.,I L _J e. i i Cottonwood Lift Station ! Pre-Design Report recreation hall is 15,000 GPD or 10 @pm. Assuming a wet weather 1/I rate of 1200 GPD per acre, the 0 contribution is 15,000 GPD or 11 gpm. This translates to a total peak flow rate of 145 gpm at full development. When design of the lift station begins, this ; figure should be compared with actual historical data,if available. l ++ EXISTING CONDITION S Facility Description ! Records indicate the lift station was built in 1960. No records exist of any major a modifications to it including pump and/or motor replacement. Most of the information in this section of the report was obtained from a site investigation and interviews with „I City personnel. The structural integrity of this 30-year old facility not known. The lift str.tion consists of a below grade 6-foot diameter, 16400t depth concrete wet well, 1 y which is unheated and poorly lighted. The lift station pumps are wet well mounted. Access and Ventilation Access to the dry well is by a ladder that tegirs in a 24" diameter hatch set 9" above grade. Access t,,the wet well is by t,ladder ti at begins in a 12" x 18'- opening directly below the lift station access. Ventilation, which is inadequate,is provided by a 4" steel J pipe connecting the wet well to fresh air above grade. The only above-grade appurtenances are the power service and control equipment. The size of the access to the dry well is adequate and this portion of the ladder is in good condition. The ladder to the wet well has corroded and is near failure. Furthermore,the opening to the wet well is unsafe because it is located at the base of the lift station 1 access ladder which someone could mistake the opening for the floor of the dry well and fall into the wet well. The opening to the wet well is small making it very difficult to transport an injured person through it. Further, the ladder has corroded and is near failure. "! Visual Inspection - Wet Well J A visual inspection of the wet well interior revealed no major structural failures or cracking. However,the wet well is corroded and its ability to resist leaks is not known. Inlet and Outlet to \Vet Well - The gravity sewer inlet is located above the high water level in the wet well, which is undesirable because it does not allow scouring of the pipe inlet for pump suction. i _ Wastewater is discharged via a 6" steel pipe approximately 120 feet to a METRO j manhole in Maple Valley Highway. Wet well overflow is discharged to the Cedar River. I - 3 rtenxeranrrmrnos u, I — i LJ Cottonwood Lift Station Prc-Design Report Although such disclarge is infrequent, it is an unnecessary occurrence and would not happen if adequate detention storage and a functional telemetry system were provided. Pump Operation Pump operation is controlled by four level controls. One pump is called to run when the liquid level reaches the high water level and is called to stop when the fluid level reaches the low water level. Pump operation is alternated each pumping cycle. If the liquid level rises to a second high water level, the stand' , pump is called to run. Should the _ liquid level continue to rise and reach the alarm level sensing element, an alarm is sent to the City Shop. An alarm is also triggered for low-level condition, power failure, and telemetry failure. The vacuum prime system on the existing pumps clogs and requires frequent • maintenance. The existing pumps are several years old and vill soon begin to incur ' more fiequent maintenance. 1 Several years ago it was discovered that internal parts of the check valve had completely corroded and were replaced at that time. 1 " Grease 1 The Citv crews have noted an ongoing problem with grease buildup iu the wet well, which if excessive, results in increased pump and motor maintenance. Currently, the wet well is cleaned at least once a month. Telett.-try and Control Equipment The electrical control and alarm monitoring equipment is old and unreliable. The design and condition of the existing control equipment make it difficult to maintain and repair. 1 Many of its components are no longer being manufactured and are unavailable J y CONCLUSIONS ! In reaching the following conclusions, we assumed that an easement of sufficient area (approximately 50'x 50')could be obtained. If it cannot be obtained,alternative design qmodifications may be necessary. We also assumed that the existing lift station must w remain operational until the proposed improvements can be put into service,which may require a temporary facility or use of a sewage vactor trek. i -^ Pump Replacement We recommend that the pumps be replaced by a more reliable pump system such as iflooded suction or submersible pumps. The existing pumps and motors may be salvaged for spare parts. y 4 a[A QXMRTNCOt S411 i A � A' r-- -1 Cottonwood Lift Station i Pre-Design Report Mechanical Eauipment It is our recommendation that all of the mechanical equipment be replaced. i Wet Well Replacement Given that the pumps and other mechanical equipment need to be replaced; that the structural integrity of the existing facility is unknown;and that Ordinance 4147 requires secondary containment,it would be more cost effective to replace the existing wet well _ with a new one that has secondary containment rather than salvage the existing one. I A new wet well should be sized to provide at least one hour of response time in the event that power or a pump fails. This would eliminate the need for an overflow discharge to the river. _ The secondary containment should be sized to completely surround the wet well and allow access for maintenance and sewage removal in the event of a failure of the wet well. The secondary containment should be designed with a sump and sloping floor to ease sewage cleanup. An inside drop connection should be added to the new wet well to redirect the incoming sewage to provide scouring of the pump suction inlet. This would help eliminate clogging problems at the suction inlet. y Telemetry and Control System Rerlacem n The control system should be replaced. It would be m, cost effect ve in the long range -� to replace the control system than to repair it. Alro,a new control..nd telemetry system should contain additional alarms for intrusion,water in dry we!, and pump failure, as well as complete sewage leak monitoring and alarm. y j The electric,! service disconnect switch should be replaced with one that provides adequate pi otection to the motor starters and the alarm system. e Access Imprcvement Access to both the wet well and dry well should be safe and of adequate size. RECOMMENDATIONS Several package lift stations are available on the market that meet the preceding r criteria. A secondary containment vessel would be designed and constructed to enclose the lift station. To reduce costs,both the wet well and secondary containment could be constructed out of precast manhole sections. 5 ncn,wropr.ronwsa� L__ Cottons»od Lift Station Pre-Design Report PROPOSED ALTERNATIVEs Alternative No. 1 - Submersible This location is a ideal environment for a wet well mout,ted submersible pump and motor system because of its susceptibility to flooding. As long as the electrical and control equipment can be located above the flood level,the submersible a ternative is the most reliable. This alternative also has minimum visual impacts and the highest level of vandal resistance, both important considerations since it is adjacent to an existing apartment complex. Because of the ability to pump down to the pump intake level,the submersible pumps typically experience fewer problems with grease and floating solids build-up. The Primary disadvantage with the submersible pump system is the maintenance of hardware that has been immersed in the sewage. Preliminary discussions with maintenance personnel have been Positive regarding the submersible system. We recommend this �Iternative because of its low cost and high reliability. Alternative No 2 - Selz Priming „ An above grade mounted,self priming station is not well suited for this application. The self printing station has a single advantage in that it provides easy access to the pumps and motors, however it has many disadvantages. The self p iming pumps are the least reliable and require the greatest maintenance. The above grade equipment cannot be made flood proof,and these stations are noted for high noise emissions. This is a particular disadvantage in this location since it is adjacent to an existing apartment complex. J This alternative is not recommended, due to its reliability record and potential noise impacts. -J Alternative No 3 - Wet Well/Dry Well The separate wet well and dry well type stations are some of the most reliable available, "i and provide the easiest and safest access,and minimum site impacts. They are resistant —1 to vandalism and have very low noise emissions. They are also the most expensive system to construct and are also very difficult to protect from flooding. 1 -- This alterative is not recommended due to its adverse flooding impacts and higher mastruction costs. i — Table 1 summarizes the advantage and disadvantages of each alternative and Table 2 ..summarizes the anticipated construction and engineering costs. i c -- IM �N St 111 iN Si L J K su Ilnnnn� MA SI SlAom '< w R i M IIA Sl >• z �LJ K qA Cl K dM SK BSI '.v�y,/ M. OFtN►000 Y / � IL YS SI a1E1MY si POTABLE ul ana WATER K aw si r q agwy WELLS ■P "ap^ [ZONE71 — .\OUIFER sTasl " �i IR. ° PROTION AREA AM s ®® cQ \ COTTONWOOD \ aaw LIFT STATION N \ \\N a� pan y 4 SU a T S,M19 s.nA SI PA a r.�r, nnl I FIGUR * V COTTONWOOD LIFT STATION SITE WI P CITY OF RENTON I APPROX. 1300' —J i j 1 FIGURE 2 OTY OF RENTON COTTONWOOD LIFT STATION 1991-_t--1992 SEPTEYBER OCTOBER NOWMBER DECEMBRI MMIARY FEBRUARY MARCH APRIL AUGUST SEPTEMBER OCT NOVFMRLR 1 TASK ONE 9/RNEY INFORMATION AS-BLALT REWEW PRELIMINARY SITE PLAN I A EASEMENT COORDINADON TASK TWO 9TE PLANS ; MECHANICAL PLANS WE WELL DETAILS ELECTRICAL AND CONTROL STRUCTURN CONTRACT 9'ECIFICATOIS TASK THREE COST ESTIMATE • i I I PRINT OOCLAIENIS AWARD EVALUATION I I I I TASK I" ( ' CONSTRUCTOR ' 7 ' PERIODIC SITE COSERVAITON ' I i • ( A W • • • 1 • ISN[W 9IBMITIAIS 7 I 1 PROCESS GRANGE ORDERS ' ' 1 • W PROGRESS PAWENT$ 1 I I WI a •t •� •1 AS-BAT RECORDS I 1 0 A M MANUALS ( I TASK FITS SHORLNE PERMIT J L14 , { y ;=Y•s:' y COTTONWOOD LIFT STATION 1 CONSTUCTIOW OI TIONS&EVAW 4TlON TABLE 7 CONSTR ENGR TOTAL .)VANTAGES DISADVANTAGES COST COST COST e SUBMERSIBLE Minimum visual impact Difficult pump accus $340,000 St1,000 S400,000 Flood resistant Confined work space Vandal resistant :lump maintenance I" Min. _jrase problem Minima! t1 - 3 solids SELFPRIMaVG Access For maintenance Least reliable pump system $375,000 S70,000 S445.000 Low visual impact High maintenance pumps Grease buildup problems .{ High noise Potential Rood damage WET WEWDRY WELL Easy access Potential:lewd damage S450.000 S48,000 $478,000 W uther protected Confined work space Low noise Grease buildup problems Vandal resistant Low visual impact eReliable pump system � r k t r COTTONWOOD LIF F. STATION CONSTRUCTION COST ESTIMATES TABLE 2 j OPTION OPTION OPTION :TEM DESCRIPTION ONE TWO THREE CONSTRUCTION I Wet w,Wsuondary containment $55.000 $106.000 S105.000 Lift station $105.000 585,OW $123,000 3 Force.mmIMETRO wnnution $42.000 S40,0W 54W,0W 4 weather shelter SD $0 S9.600 5 Elutrical and control S62,000 S62.000 S62,0W 6 Temporary servict S9,000 S9,0D0 $9,000 7 P;molwon $6,000 $6•000 S6,D)D 8 Sitc restoration S7,000 S7,000 $7,000 SUBTOTAL S2 ,000 `315,000 S361,600 CONTNGENCY(10%) S28.6W $31,560 S36,160 SALES TAX $25,797 $28.413 S32,616 t CONSTRUCTION SUBTOTAL S340,397 $374,913 $430.376 rr ADMINISTRATION ' 1 Design S54,000 S64,000 $42.000 2 Services dying crostrunion $1.682 $1,682 $1,682 3 Legal services S4.279 54,279 $4,279 ' ADMINISTRATION SUBTOTAL S59,961 S69,961 S47,961 TOTAL TOTAL PROJECT COST S400.358 $444,874 5478,337 i n: :Y a. A Me r- •• T: