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HomeMy WebLinkAboutApplication APPLICANT 3/30/2023 (3)DEVELOPMENT AND PUBLIC WORKS SPRINGFIELD 225 FIFTH STREET OREGON SPRINGFIELD, OR 97477 PHONE: 541.726.3753 FAX: 541.726.1021 aww.spnng5etd-orgov STORMWATER MANAGEMENT SYSTEM SCOPE OF WORK (Area below this finefiIIed ow by Applicant) (Please return to Clayton VeEnchern @ City of Sprirililield Development and Public Works; Fax # 736-1021, Phone k 736-1036), email: cmceachern@smmg feid-or. gov Project Name: EC Cares Springfield Applicant: Anna Backus, KPFF Assessors Parcel #: 170335120- 6700,6800 Date: 3/16/2023 Land Use(s): Modular classroom building/parking Phone #: 541-735-9249 Project Size (Acres): 0.46 Fax #: Approx. Impervious Area: 10,369 SF Email: Anna.Bacl u @kpff.com Project Description (Include a copy of Assessor's map): Project will include a modular classroom building with an outdoor play area, sidewalks, and a parking lot. Drainage Proposal (Public connection(s), discharge location(s), etc. Attach additional sheet(s) if necessary: All stormwater will be infiltrated on site with a raingarden, filter strip and a soakage trench. Proposed Stormwater Best Management Practices: Concrete buck washout, construction entrance, in protection, silt fencing — (Arra below this One filled oat In, the Clo, andReturnedholleAmuftoead (At a minimum, all boxes checked by the City on the front and back of this sheet shall be submitted or an application to be complete for submittal, although other requiremsmn, maybe necessary.) Drainage Study Type (EDSPM Section 4.03.21 (Note, UH may be substituted for Rational Method) ❑ Small Site Study — (use Rational Method for calculations) ❑ Mid -Level Development Study — (use Unit Hydrogmph Method for calculations) ❑ Full Drainage Development Study —(use Unit Hydrograph Method for calculations) Environmental Considerations: ❑ Wellhead Zone: ❑ Hillside Development: ❑ Wetland/Riparian: ❑ Floodway/Floodplain: ❑ Soil Type: ❑ Other Jurisdictions Downstream Analysis: ❑ N/A ❑ Flow line for starting water surface elevation: ❑ Design HGL to use for starting water surface elevation: ❑ Manhole/Junction to take analysis to: Return to Clayton McEachern @ City of Springfield, email: cmceachem@springfie"d ,gov, FAX: (541) 7361021 COMPLETE STUDY ITEMS ae orseial ose onm: *Based upon the information provided on the front ofthis sheet, the following represents a minimum ofwhat is needed/b, an application to be complete for submittal with respect to drainage; however, this list should not be used in lieu ofthe Springfield Development Code (SDC) or the City's Engineering Design Manual Compliance with these requirements does nor constitute site approval; Additional site specie information may be required Note: Upon scoping sheet submittal, ensure completedform has been signed in the space provided below: Interim Design Standards/Water Quality (EDSPM Chapter 3 Req'd N/A ❑ ❑ All non -building rooftop (NBR) impervious surfaces shall be pre-treated (e.g. multi-chambered catchbasin w/oil filtration media) for stormwater quality. Additionally, a minimum of 50% ofthe NBR impervious surface shall be treated by vegetated methods. ❑ 7 Where required, vegetative Stormwater design shall be consistent with design standards (EDSPM Section 3.02), set forth in Chapter 2 of the Eugene Stormwater Management Manual. For new NBR impervious area less than 15,000 square feet, a simplified design approach may be followed as specified by the Eugene Stormwater Management Manual (Sec2.4.1). ❑ If a stormwater treatment swale is proposed, submit calculations/specifications for sizing, velocity, flow, side slopes, bottom slope, and seed mix consistent with City of Springfield or Eugene's Stormwater Management Manual. ❑ Water Quality calculations as required in Section 3.03.1 ofthe EDSPM. ❑ ❑ All building rooftop mounted equipment, or other fluid containing equipment located outside of the building, shall henrnvided with sernndary containment or weather resistant enclosure. ❑ ❑ Drainage study prepared by a Professional Civil Engineer licensed in the state of Oregon. ❑ ❑ A complete drainage study, as required in EDSPM Section 4.03.1, including a hydrological study map. ❑ ❑ Calculations showing system capacity for a 2 -year storm event and overflow effects of a 25 -year storm event. The time of concentration (Tc) shall be determined using a 10 minute start time for developed basins. Review of Downstream System(EDSPM Section 4.03.4.0 ❑ ❑ A downstream drainage analysis as described in EDSPM Section 4.03A.C. On-site drainage shall be governed by the Oregon Plumbing Specialty Code (OPSC). Elevations ofthe HGL and flow lines for both city and private systems where applicable. ❑ Design of Storm Systems (EDSPM Section 4.04). ❑ ❑ Flow lines, slopes, rim elevations, pipe type and sizes clearly indicated on the plan set. ❑ Minimum pipe cover shall be 18 inches for reinforced pipe and 36 inches for plain concrete and plastic pipe materials, or proper engineering calculations shall be provided when less. The cover shall be sufficient to support an 80,000 Ib load without failure of the pipe structure. ❑ ❑ Manning's `n" values for pipes shall be consistent with Table 4-1 of the EDSP. All storm pipes shall be designed to -h;- .,.fth— III fret — ceennd at 0.5 nine fill based on Table 4-1 as well. Existing and proposed contours, located at one foot interval. Include spot elevations and site grades showing how site drains. Private stormwater easements shall be clearly depicted on plans when private stonnwater flows from one property to another. ❑ Drywells shall not receive runoff from any surface w/o being treated by one or more BMPs, with the exception of residential building roofs (EDSP Section 3.03.4.A). Additional provisions apply to this as required by the DEQ. Refer in the website: hup-// dea.state.or.us/wo/iiic/uic.htin for more information. ❑ ❑ Detention ponds shall be designed to limit runoff to pre -development rates for the 2 through 25 -year storm events. *This form shall be included as an attachment, inside the front cover, of the stormwater study. *IMPORTANT: F.NGINF,ER PLEASE READ BELOWAND SIGN! As the engineer of record, I hereby certify the above required items are complete and included with the submitted stormwater study and plan set. Signature Date Form Version 5: June 2015 Memorandum Page 1 of 3 DATE: March 16, 2023 PROJECT: 2200394 -EC Cares Springfield TO: Clayton McEachern City of Springfield PHONE: 541.736.1036 EMAIL: cmceachern@springfield-or.gov TANOWNa SUBJECT: Stormwater FROM: Randi Rondeau KPFF Consulting Engineers PHONE: 541.632.8064 EMAIL: randi.rondeau@kpff.com This memo has been prepared to describe the stormwater work for the EC Cares Springfield project. The existing site has optimum infiltration rates, so on-site retention will be utilized for runoff. Existing Conditions The project site, located at the corner of G Street and 8th Street in the City of Springfield, consists of an open field. Overall, the site is flat. It's assumed that most of the stormwater infiltrates on-site. The site area consists of tax lots 6700 and 6800 with a total property area of .46 acres. See Exhibit 1 in Appendix 1 for the drainage basin areas and limits of storm analysis. Proposed Stormwater Quantity Per the USDA Web Soil Survey, the soil on site is Malabon-Urban Land Complex. This soil type belongs to Hydrologic Soil Group C. An infiltration test was performed on site and summarized in the Infiltration Report by Branch Engineering dated 11/28/2022. The report found a high infiltration rate of 19 inches/hour at 38 inches deep. A soakage trench with a 3 -foot depth will be used to infiltrate on-site runoff. Preliminary sizing of the soakage trench was done using the City of Eugene's Subsurface Facility Sizing spreadsheet with a design infiltration rate of 9.5 inches/hour (half the tested infiltration rate). No runoff will leave the site after the improvements are completed. Therefore, the City of Springfield's stormwater quantity requirements are met. See Appendix 4 for the Infiltration Test Report. Methodology Stormwater Requirements The City of Springfield references the Eugene Stormwater Management Manual (SWMM) for the requirements for water quality treatment. The 2014 City of Eugene SWMM implements a hierarchy system in which infiltration facilities must be considered first. If infiltration is not possible, filtration facilities must be sized. The City of Springfield requires that at least 50 percent of vehicular areas are treated via vegetated methods. As described above, the on-site soils are favorable far infiltration. A rain garden will treat the runoff from most of the paved areas on site. The roof areas will be directed to the soakage trench and treated runoff from the rain garden will also be infiltrated in the soakage trench. A filter strip will provide treatment for a small, paved area at the south edge of the building. 800 Willamette Street, Suite 400, Eugene, OR 97401 541.684.4902 FAX 541.684.4909 Eugene, OR Portlond, OR Memorandum Page 2 of 3 March 16, 2023 Proposed Stormwater System The proposed site improvements include a modular classroom building with an outdoor covered play area, sidewalk and parking. Roof runoff will be piped directly to the soakage trench. Runoff from the northwest portion of the site and parking area will be captured through catch basins and piped to the rain garden. Runoff from the northern portion of the site will sheet drain to the rain garden and be treated prior to inf Itrating through the soakage trench. Runoff from the south portion of the site will be treated through a filter strip adjacent to the ramp at the front entrance. The site is divided into three drainage basins, described in detail below. There is no impervious area on the existing site. However, the proposed improvements include 10,110 square feet of impervious area. All calculations and details for the site and facilities are included in Appendix 2. • Basin A: A rain garden will serve as the filtration facility for the majority of the impervious area from parking, sidewalks and hardscape over the 0.46 -acre site. Basin A has 7,416 square feet of impervious area and 10,329 square feet of pervious area. The rain garden has a treatment area of 85 square feet, with a treatment depth of 6 inches. This allows for sufficient storage capacity to filter the water quality design storm. An overflow inlet will be set 6 inches above the rain garden treatment surface for overflow in larger rainfall events. Runoff in the parking area will sheet drain to a catch basin in the northwest corner of the parking area, where it will be hard piped to the rain garden. The northwest portion of the entire site will slope towards a catch basin which will also be hard piped to the rain garden. The remaining area will sheet flow towards the rain garden where it will be treated, then piped to the adjacent soakage trench for infiltration. • Basin B: A soakage trench will serve as infiltration area for the roof runoff on-site, as well as treated runoff through the rain garden. The total combined roof area for the modular building and the covered play area is 3,736 square feet, which will have hard piped connection from downspouts to the soakage trench. This runoff will be infiltrated on-site. • Basin C: A filter strip will serve as filtration area for the southwest portion of the site. The total impervious area to be filtered through this facility is 383 square feet. The facility must be one-fifth of the impervious area size for adequate sizing. A total filtration area of 98 square feet was chosen for this facility. Analysis Stormwater Runoff Calculations The runoff for the impervious areas has been calculated and the rain gardens have been sized using the Springfield Stormwater Facility Calculator. The calculator determines runoff using the Santa Barbara Urban Hydrograph (SBHU) Method and NRCS 24-hour Type 1A Hyetograph as outlined in Appendix M of the City of Eugene SWMM (see Appendix 2 for the Stormwater Facility Calculator results). Memorandum Page 3 of 3 March 16, 2023 For analysis purposes, each basin of the property required the following information as input for the computer model: • Impervious Area (Ai), in acres • Curve Number(CNi), impervious • Travel Time (Tc) • Total Precipitation Precipitation data for the respective storms for City of Springfield Design Storms are shown in Table 1: Tabie 1:24-HOWPrec1rWa ion for5orinafiel4. OR Storm Event Inches WQ 0.83 2 -Year 5 -Year 10 -Year E4.80 25 -Year 100 -Year To size the rain gardens, the following information was needed: • Bottom Area, in feet • Bottom Width, in feet • Storage Depth, in inches • Side Slopes This information, as well as the runoff results from the proposed basins, is shown in Appendix 1. The rain garden, soakage trench and filter strip meet the requirements of the City of Springfield. Based on the requirements of the Stormwater Management Manual, no errors were found in the stormwater system design. The facilities and conveyance components have enough capacityto handle the required storm events and should be approved as designed. Attachments: Appendix 1: Proposed Basin Map Appendix 2: Proposed Runoff and Water Quality Calculations Appendix 3: Stormwater Scoping Sheet Appendix 4: Infiltration Test Report Appendix5: Operations and Maintenance Plan 2200394 -kg p4 � 5 x X x C W d a Q ac � a o Q w a CL H m �o CO W y 0CL u ZZ C H � ❑ i r ` E 5 �7 ❑ I 7 I III —__ ❑ I ` i � e i ux3 sri aeew-w=oe-ssmwe\weisWs;=aa-s����ow\mw-roux\ �o s-==��o-oa-oo-esmoex\emc\s\=\o :=ee ,�„ Appendix 2 SBUH Calculation Worksheet for City of Springfield Storm Events 1SU Project Name: EC CARES SPRINGFIELD Date: 02.06.2023 Designer: RRR Basin: 1 User -Supplied Data Pervious Area Impervlous Area Pervious Area, SF Pervious Area, Acres Pervious Area Curve Number, CNpery Time of Concentration, Te, minlRes 10,3291 Impervious Area, SF 7,416 Impervious Area, Acres 0.17 Impervious Area Curve Number, Chimp 9g Note: minlmum Tclsfive minutes 0.24 74 5 Total Project Area, Acres 1 0.411Total —WQ Project Area, Square Feet 17,245 Recurrence Interval Wq 2 -Yr 5 -Yr 10 -Yr 25 -Yr 50 -Yr 1OLr Peak Flow Rate, Opeak, on 0.03 0.20 0.24 0.29 11.34 #VALUE! 0.38 Total Runoff Volume, V, cubic Feet 391 2,846 3,/53 4,(178 4,719 #VALUE! 5,7A0 Time to Peak Runoff, hours 7.831 7.831 7.01 7.831 7.831 #VALUEI 1 7.83 RunoffMidrog aph 0.45 —WQ -- —2 -Year 0.40 —5 -Year 0.35 —10 -Year —25 -Year 0.30 —50 -Year „ 025 —100 -Year o � 0.20 rc 0.15 0.10 0.05 0.00 0 500 1000 1500 2000 2500 Time, minutes 8bOw111MKteo—t,SuTee00 Ersene,OR97401 541.66449e3 reffmm Springfield Stormwater Facility Calculator Instructions: 1. Choose Facility Type 2. Choose shape 3. Complete information in highlighted cells Facility Peak Flow (CIS) Raingarden Rock Capacity WQ Shape11in 351 N/A Below-Grade Bottom Area: 2,794 N/A sf Bottom Width: 3,400 N/A ft Side Slope: 4,029 N/A to 1 Storage Depth: 4,671 N/A in Growing Media: #VALUE! N/A Surface Storage Capacity 5,189 57 cf Infiltration Area @ 75% 151 sf GM Infiltration Rate 2.5 in/hr Infiltration Capacity (avg) 0.009 cfs RPf111tC Omar ProleR Name: EC CARES SPRINGFIELD WATER QUALITY EVENT PASS ROCK CAPACITY N/A SURFACE CAPACITY R% Recurrence Interval Peak Flow (CIS) Volume (cf) Rock Capacity WQ 0.0088 351 N/A 2 -Yr 0.1974 2,794 N/A 5 -Yr 0.2437 3,400 N/A 10 -Yr 0.2919 4,029 N/A 25 -Yr 0.3416 4,671 N/A 50 -Yr #VALUE! #VALUE! N/A 100 -Yr, 0.3822 5,189 N/A Meets Infiltration? Filtration Only 1201 Oak Street, Suite 100 Eugene,OR97401 541.6844902 kpH.com Basin: l Date: 02.06.2023 Impermeable Liner lepff Projed Name: EC CARES SPRINGFIELD Basin: l Water quality Event Surface Facility Modeling Date: 02 06.2023 0.0350 % �Surfacelnflow 0% 0.0300 ---IWIS-I Capacby 0% 0.0150 0% ��Permlation to Subsurface y 0.0300 V 0% 0.0150 � K ��� OveRlow 0% o% 0.0100 — Surface Capacity 0% —___ —__------� e0% 0.0050 90% 0.0000 100% 0 500 1000 1500 2000 2500 Time, minutes 800 Willamette Street, Suite 400 EUene,01197401 541.684.4902 kpff.com Storrnwater Subsurface Filtration/Infiltration Facility Sizing Spreadsheet 24 Hour Storm, NRCS Type 1A Rainfall Distribution City of Eugene Name: EC CARES SPRINGFIELD Date: 2/612023 Address: Springfield, OR Permit Number: Catchment ID: Overall Site u Ransil Rondeau ry: KPFF Consultlno Engineers Complete this form for each drainage catchment in the project site that is to be sized per the Presumptive Approach. Provitle a distinctive Catchment ID for each facility coordinated with the site basin map to correlate the appropriate calculations with the facility. The maximum drainage catchment to be modeled per the Presumptive Approach is t acre (43,560 SF) For infifiration facilities in Class A or B soils where no Infiltration testing has been perfromed use an infiltration rate of 0.5 inlhr. icode 'Yes"from the dropdown boors below next to the design standards requirements for this facility. Yes -Soasaa=rremn�d,aim=e-.—.i ening wu aymre Frevenmenl to marl n Iuro�nW.bt ...Inem=,ns Pollution Reduction (PR) Flow Control (FC)l Yes Destination(DT( Yesna �mavanon temiymar be mason as me reanrrhnammen arsu,araa,aamraraare Total Square Footage Impervious Area= 11158 suit Total Square Footage Pervious Area= 6587 sgft Impervious Area CN=l 98 Pervlous Area CN=l 74 Total Square Footage of Drainage Area= 17745 sft Time of Concentration Post Development=Omin Welgbted Averege CN= 39 Time of Concerdratian Tested Soil Infiltration Rate=In/hr fs%e NOle al Destination Deem= 9.5 iNhr Oeslgn Soil Infiltration Rate=1 19 Ielm Soil lnf ltration Rate Re uirement Ralrrlall De th castors tone Pollution RetluGion 0.81nrl1es Water Ouali Flow Coniml I 36inehes IFI..dConVal Destination 1 3.9 inches Flood Control 25 -year storm Facility Surface Effective Facility Percent Storage Depth ..m n.l v,.inss int Drainage Rock, Layer 1 1 36.01 40yl 14.4 0.0 0.0 D.0 113112023-2'10 PIV Totals= 36.0 in 14.4 in 1 Pollution a uction-Calcu a icn Resultai Peak Flow Rate to Stormwater Facility 0.011 ds Peak Facility Overflow Nat 0.000 da Total Runoff Volume to Stoato miw Facility= 278 d Tom] Overflow Volume= 0 d Max. Eff. Depth of Stormwater In Facility= 0.0 in Dmwdown Time= 0.2 hours Ves Facility Sizing Meets Pollution Reduction Standards? YEe Meeffi Requirement MNo Facility Flooding? =Meets Requirement for Maximum of IS Hour Drawdown Tlme? Flow CordmLCalculatlon Results Peak Flow Rata to Stormwater Facility= 0.282 da Peak Facility Overflow Rete= 0.000 ds Total Runoff Volume to Stm.ft Facility• 3626 d Taal Overflow Volume= 0 d Peak Offsite Flow Rate Max. Eff. Depthof Stormander In Facility= 3.1 in Filtration Facility Underdrain NW chs Drewdown Time= 0.2 hours Pn>Develo ro I Runoff Data Peak Flow Rale = 0.116 cfa Total Runoff Volume= 1936 cf Yes Facility Sizing Meets Flow Control Standards? Meets Requirement for Post Development of Bite flow lass or equal to Pre-Development FlovlV YES Meets Requirement for Maximum of 18 Hour Drawdown Time? Destination-Iculation Results Peak Flow Rate to Stormwater Facility 0.318 da Peak Facility Over0ow Rate= 0.000 cis Total Runoff Volume to Stormweter Facility= 40384 Total Overflow Volume= 0d Max. Eff. Depth of Stormweter in Fadsh 12.0 in Drawdown Time= 0.2 hours Ves Facility Sizing Meets Destination Standards? VES Meets Requirement of No Facility Flooding? YES Meets Requirement for Maximum of 30 hour Drawdown Time? 1131Q023-2:10 PM Designed By: RR EC CARES SPRINGFIELD- FILTER STRIP DESIGN 02/06/2023 Checked By: AB Filter Strip Calculations Note: All Filter Strip Calculations are based on the SIM Form & the City of Eugene Stormwater Management Manual ;M Impervious Required Filter Area Provided Capacity Basin Area (sf) Strip Area sf) I IS Used 2 1 3831 771 981 78% ;M Appendix 3 DEVELOPMENT AND PUBLIC WORKS —OREGOX SPRINGFIELD, OR 97477 PHONE: 541.726.3753 FAX.541.726.1021 www.springfieldorgav STORMWATER MANAGEMENT SYSTEM SCOPE OF WORK — — (Area below the RnefrRedont by Applicant) (Please return to Clayton McEachern @ City ofSpringfieldDevelopmenl and Public Works, Fax # 736-1021, Phone # 736-1036), email cmaeachern@springfield-or.gov Project Name: BC Cares Springfield Applicant: Alma Backus, KPFF Assessors Parcel#: 170335120-6700,6800 Date: 3/16/2023 Land Use(s): Modular classroom building/parking Phone #: 541-735-9249 Project Size (Acres): 0.46 Fax #: Approx. Impervious Area: 10,369 SF Email: Anna.Backus@kpffcom Project Description (Include a copy of Assessor's map): Project will include a modular classroom building with an outdoor play area, sidewalks, and a puking lot. Drainage Proposal (Public connection(s), discharge location(s), etc. Attach additional sheet(s) if necessary: All stormwater wil I be infiltrated on site with a raingarden, filter strip and a soakage trench. Proposed Sto rnwater Best Management Practices: Concrete truck washout, construction entrance, inlet protection, silt fencing (Area below this line fr0ed oat ba, the Cay asd.Retaxned to the A !smut) (At a minimum, all boxes checkedby the City on the front and back ofthis.sheet shall be cubmilted or an application to be complete or submittal, although other requirements may be necessa </ Drainage Study Type (EDSPM Section 4 03 2)� (Note UH may be substituted for Rational Method) ❑ Small Site Study — (Use Rational Method for calculations) ❑ Mid -Level Development Study — (use Unit Hydrograph Method for calculations) ❑ Full Drainage Development Study — (use Unit Hydrogaph Method for calculations) Environmental Considerations: ❑ Wellhead Zone: ❑ Hillside Development: ❑ Wetland/Riparian: ❑ Floodway/Floodplain: ❑ Soil Type: ❑ Other Jurisdictions Downstream Analysis: ❑ N/A ❑ Flow line for starting water surface elevation: ❑ Design HGI, to use for starting water surface elevation: ❑ Manhole/Junction to take analysis to: Retum to Clayton McEachem @ City of Springfield, email: craceachem@springfield-o ,gov, FAX: (541) 736-1021 COMPLETE STUDY ITEMS arocia111�oN *Based upon the information provided on the front of this sheet, the following represents a minimum ofwhat is neededfor an application to be complete for submittal with respect to drainage; however, this list should not be used in lieu ofthe Springfield Development Code (SDC) or the City's Engineering Design Manual Compliance with these requirements does not constitute site approval; Additional site specie information may be required. Note: Upon scoping sheet submittal, ensure completed form has been signed in the space provided below: Interim Design Standards/Water Quality (EDSPM Chapter 3 Req'd N/A ❑ All non -building rooftop (NBR) impervious surfaces shall be pre-treated (e.g. multi-chambered catchbasin w/oil filtration media) for stormwater quality. Additionally, a minimum of 50% of the NBR impervious surface shall be treated by vegetated methods. ❑ Where required, vegetative stormwater design shall be consistent with design standards (EDSPM Section 3.02), set forth in Chapter 2 of the Eugene Stormwater Management Manual. ❑ ❑ For new NBR impervious area less than 15,000 square feet, a simplified design approach may be followed as specified by the Eugene Stormwater Management Manual (Sec2.4.1). ❑ ❑ If a stormwater treatment Swale is proposed, submit calculations/specifications for sizing, velocity, flow, side slopes, bottom slope, and seed mix consistent with City of Springfield or Eugene's Stormwater Management Manual. ❑ ❑ Water Quality calculations as required in Section 3.03.1 of the EDSPM. ❑ F] All building rooftop mounted equipment, or other fluid containing equipment located outside of the building, shall .--- :,--____A-_.....«r..:«««.. ...... _i,_eveicnnk -1- ­ A downstream drainage analysis as described in EDSPM Section 4.03A.C. On-site drainage shall be governed by the Oregon Plumbing Specialty Code (OPSC). Elevations of the HGL and flow lines for both city and private systems where applicable. Design of Storm Systems (EDSPM Section 4.04). Flow lines, slopes, rim elevations, pipe type and sizes clearly indicated on the plan set. Minimum pipe cover shall be 18 inches for reinforced pipe and 36 inches for plain concrete and plastic pipe materials, or proper engineering calculations shall be provided when less. The cover shall be sufficient to support an 80,00016 load without failure of the pipe structure. ❑ Manning's "n" values for pipes shall be consistent with Table 4-1 of the EDSP. All some pipes shall be designed to Existing and proposed contours, located at one foot interval. include spot elevations and site grades showing how site drains. Private stormwmer easements shall be clearly depicted on plans when private stormwater flows from one property to another. ❑ ❑ Drywells shall not receive runoff from any surface w/o being treated by one or more BMPs, with the exception of residential building roofs (EDSP Section 3.03.4.A). Additional provisions apply to this as required by the DEQ. Refer to the website: huv-//..dea.state.o,.us/wa/uicluic.htin for more information. Detention ponds shall be designed to limit runoff to pre -development rates for the 2 through 25 -year storm events. *This form shall be included as an attachment, inside the front cover, ofthe stormwater study. " IMPDRTANT. ENGINEER PLEASE READ BF-7.OWAND SIGN! As the engineer of record, I hereby certify the above required items are complete and included with the submitted stumrwater study and plan set Signature Date Form Version 5: June 2015 Drainage study prepared by a Professional Civil Engineer licensed in the state of Oregon. A complete drainage study, as required in EDSPM Section 4.03.1, including a hydrological study map. Calculations showing system capacity for a2 -year storm event and overflow effects of a 25 -year some event. F-1 n The time of concentration (Tc) shall be determined using a 10 minute start time for developed basins. A downstream drainage analysis as described in EDSPM Section 4.03A.C. On-site drainage shall be governed by the Oregon Plumbing Specialty Code (OPSC). Elevations of the HGL and flow lines for both city and private systems where applicable. Design of Storm Systems (EDSPM Section 4.04). Flow lines, slopes, rim elevations, pipe type and sizes clearly indicated on the plan set. Minimum pipe cover shall be 18 inches for reinforced pipe and 36 inches for plain concrete and plastic pipe materials, or proper engineering calculations shall be provided when less. The cover shall be sufficient to support an 80,00016 load without failure of the pipe structure. ❑ Manning's "n" values for pipes shall be consistent with Table 4-1 of the EDSP. All some pipes shall be designed to Existing and proposed contours, located at one foot interval. include spot elevations and site grades showing how site drains. Private stormwmer easements shall be clearly depicted on plans when private stormwater flows from one property to another. ❑ ❑ Drywells shall not receive runoff from any surface w/o being treated by one or more BMPs, with the exception of residential building roofs (EDSP Section 3.03.4.A). Additional provisions apply to this as required by the DEQ. Refer to the website: huv-//..dea.state.o,.us/wa/uicluic.htin for more information. Detention ponds shall be designed to limit runoff to pre -development rates for the 2 through 25 -year storm events. *This form shall be included as an attachment, inside the front cover, ofthe stormwater study. " IMPDRTANT. ENGINEER PLEASE READ BF-7.OWAND SIGN! As the engineer of record, I hereby certify the above required items are complete and included with the submitted stumrwater study and plan set Signature Date Form Version 5: June 2015 November 28, 2022 Luke Helm Via Email: Ihelm@umegon.edu BE: Sm hNmII cnoN TEsr Rrstn rs Tae M" a Lor No. 17-03-35-12-6900 812 G SraE r SPA GFO.n, OBEG N97477 BtuNCn ENGPIE G INC PAOJECr No. 22-515 Appendix 4 Vanch NEERING-- sf—Al Branch Engineering Inc. BED performed infiltration testing at one hand -augured hole at the approximate location shown on Infiltration Testing Map, Figure 1. 'the purpose of our testing was to provide a site-specific infiltration rate for the design of an on-site disposal system for stormwater generated from the proposed development. Site infiltration testing was conducted in a saturated test hole using the Encased Falling Head Test method in accordance with the 2014 City of Eugene Stormwater Management Manual on November 22, 2022. Infiltration testing commenced for three successive trials with water added between each trial. The soil in the hand auger boring was visually classified using the American Society of Testing and Materials (ASTM) Method D-2488. At the location of Infiltration Test 1 (IT -1), soil consisted of brown silty clay with gravel from 0- to 12 -inches below ground surface (BGS), followed by medium stiff dark brown silty clay from 12- to 36 -inches BGS and a light brown clay with sand from 36- to 40 -inches BGS. The NRCS Web Soil Survey maps the site as Malabon-Urban land complex, described as well drained soil derived from silty and clayey alluvium. Nearby well logs and NRCS soil mapping data are attached, indicating subsurface conditions are consistent with our observations. Ground Water Ground water was not encountered in the site boring, and well logs (see attached) in the site vicinity indicate static groundwater levels at 12- to 18 -feet BGS at well locations within 0.5 -mile of the site. Infiltration Data Analysis The amount of fall in the water columns were measured over time for three separate trials. The vertical hydraulic conductivity of the soil is calculated from the equations presented below. The volume of water infiltrated into a soil of consistent hydraulic conductivity is primarily dependent upon two factors, the area over which infiltration occurs and the pressure head. Using the following vadose zone equations, an estimated vertical hydraulic conductivity and rates of infiltration are presented in Table 1 for the test sites. V, Ki where: V, is the rate of fag in the water height K is the hydraulic conductivity i=H,.+L-h. its the head loss 1n Las the depth of the wetting front H„ is median water height & = V V„ is the total volume of water infiltrated A x f f is the fillable porosity (assumed to be 35%) p:503-779-2577 I w .branchengineering.rom 812 G street -Springfield HS BEI PN 22-515 q = YiA q is the average rate of water infiltration (vol./time) A is the infiltration area h_ is the cd deal pressure head of soil for sidewall wetting (assumed to be 0 inches) Recover, 1978) The soil material is assumed to be laterally homogeneous and sidewall infiltration is negligible as a 6 -inch diameter, open-ended, plastic standpipe was used for containment of the water column. Summary of Field Inffltration Test Results The results of our November 22, 2022 field testing are summarized below in Table 1. The hydraulic conductivity is based on the infiltration rate measured in the field and summarized on the attached Infiltration Data Evaluation Worksheet. Table 1: Summary of Field Infiltration Test Results Using the recommended factor of safety of approximately 2, a design infiltration rate of 10 Win is suggested. if you have any questions regarding the test method or data analysis, please contact the undersigned. Sincerely, Branch Engineering Inc, �S��P� sx�FFss� 2�. #37892PPE V 3 OREGON 2 � WgRREN� Expires: Dec. 31, 2022 Matthew Renner, P.E. Construction Engineer Attached: Figure-) Infiltration Testing Map ]nfiltration Field Data Worksheet DWRD Well Logs MRCS Soils Map Branch Engineering, Inc Andrew Park, E.I. Engineering Technician Test Depth Measured Conductivity K (in/hr) Test Location inches IT -1 38 1 19 Summary of Field Infiltration Test Results Using the recommended factor of safety of approximately 2, a design infiltration rate of 10 Win is suggested. if you have any questions regarding the test method or data analysis, please contact the undersigned. Sincerely, Branch Engineering Inc, �S��P� sx�FFss� 2�. #37892PPE V 3 OREGON 2 � WgRREN� Expires: Dec. 31, 2022 Matthew Renner, P.E. Construction Engineer Attached: Figure-) Infiltration Testing Map ]nfiltration Field Data Worksheet DWRD Well Logs MRCS Soils Map Branch Engineering, Inc Andrew Park, E.I. Engineering Technician c ".`` < asa �c a'o's*�a iY a agg �z g Y s [ � I; e y h h Y A � h a • ' f ��1 s i �FI 3 Y �,eel��z�"313 c�a,.a r.MOP xea wuo•.me ,9emmoemxzo ep ry area ep s IVOmtlpeTea91 Th11 TOee lmd AVLee fnl IW 11v/mel Ilv/ht1 ¢af Fall Tlll 32,0 1RL i9® 10.0 IMA 0 0A tW�mlatleal ) B 900 0.00 19 033 mmwu ysm aQim JLo 8 1 IeXlmmnrW 12 Tlme lmlW ,6ereetW IW IremIW UWMI ofrall T -z lin7R1 \'plume of 3Vcm Mtletl 0 "I aomlwe oso � iao io.o Seo pa3 2. Sae A P11¢2tl WeuetlmTenITU13 SY,Ie e1hJ IWWa uNmW 1 mm 1 3RA Iii] Sae 9BA 00 3Z0 OJO 1H0 M 55 RJ 393 033 19l P I Nm"n NOTfCI: TO WATER WELL t e.,w Tee thif l p ma flat copy : tbfi eeport m be I L EEPO$'Jkt' mea orlon th me e„t" OF OBE(iON STATE ENGINEER. SALEM OREGON 079B1 7Cl-fkt. ase tyye a o") wtthfnandayaaom we a.re NSU -" .211/0 $)<�n t of WdI wmdemn ' t � o�iEy.�o�e m, nee, � '� 7975 (1) OWNER.: .1 LEIA, OR. ll Name McKenziefiame McKenzieOrthopwdinC1 in Adames 14th 8 G14th & G strati+ . G,^•de ,, n (2) TYPE OF WORK (check): New Wen] DeepmN{ ❑ - Reconditioning ❑ Abandon ❑ If abandonment, de¢erfbe meterbl and procedure In Igen is. (3) TYPE OF WELL: (4) PROPOSED USE (check): Rotaq ❑ Del. ❑ Desessue 13 mdwh9al ❑ Mwldmo ❑ Cable ® Tatted ❑ nus ❑ Boned ❑ ungouw ❑ Test Well ❑ more ❑ CASING INSTALLED: Tafreadad ❑ welded ❑ ..__.8.._• in.. from .t.1. ...... _----- .ft. he ..75_..._ tc cage ...250._ Dian, bpm ....G.Lr._1e m .2;_....__...._rt Gage ...... ..._.__...._• Own. from _.._.._.__._ ft. to ..__e._____ ft. Gess ...._.—..— W PERFORATIONS: - Ferfor tadl ❑ Yea ❑ No. Type of pereremr eted Machined in ............... Bae of 118 in. b,, 3 in. _ 6pereseanmu S7 rerfwatfwa 4om ...._.YO... .._ fL to ..._.—.60 _._ SG .—�— peril nsuees from ....__. — R. to _.._.._.._.__._...._ It. penmauw. from .... ....... ....... ..... ._ f0. .mse (7) SCREENS: Well amrw Listened? ❑ Yes Rj No ....... noose M®udetureYe Name._.......__...__..._._._.__._�__.—.�______.__.____... . . . .. . ..................... Type Model Diem. ____.._ and side .... _..... 9d Swm ..._—._.__.. A. to .....�_... ft. nram.._.._._.._ fines... .__.__.. set arm ._.._._.._..._.. eL (8) WELL TESTS: waterteal a aowereed afow Wan a pump test heads? x] Yes ❑ No D M. by whomr aan¢ test ed./mln. with . It. deawde— after he. Arced. now e.p.m. Depth session flew enrowtered .......__.._.._ n. (8) CONSTRUCTION: Well Ted—Material wed _.. cement...__......_.._ ............... Wee seated from land surface ter,.20L ................._.__._.._..__ ...___._... to Diameter d wen boa to bottom d Ted --16_.. __- to Damder, d wcu rare bdoW ead -16- -- u, Nusbor of seeks of cement peed N well sed _•jg.,_�..____._........_ .mse Numbm of sada d bentonite used In wen esti ._._....__._ ....... noose Brand name of bentmns, -+..-...----....-. . .. ............ .. . . . .. . ..................... Nornbar of poweds of lookouts uts pat IN on. of water .---- ... ......... ..... _____.._--__...._._. lb../. sets. Was a delve cors used? ❑ Yes NX. lose, ...... Biu: loestiw ........ ft Type of wife" depth of strata Soothed of ...nos shnta otf Gravel e Wen No._{yJ.( e Dermic No. (10) tftA77QN' Ftb}9E3.tI counts Lane Demure weD nmvber 1 ti NE u Bedew 35 Ta 7i R 3Iy W.M. u ease. T3is R ?) W.m. Bosun, and Natrnce fres storkme w euhdvbaon or (11) WATER LEVEL: Completed well. Depth Of wbkh Wates orae fleet lewd 18 ft. Stetie level 12 ft below laud surface. rate Artesian pre. lb,. pee egnaes then. Date T TTS (12) WELL LOG: nlemater, d wee hot— eating Depth armed '75 ft. Depth of emesleted wen 75 0. Forsacoe: Describe calw. teeitme, green she apt afrueh,re of materials, and show thickness and nature of mar stedme and squffer peceftated, with at leant wr mtey for men ehinge of formation. Report each change in _ position of Sta be water Lead apt lMlwte yrhtNp81 wept -bearing Aorta. IdATBFIAL Siem To I BWL clay - n Clay, grave+ heuldea•s X18_ Date well drDling sazhive mored oa of Well is Brims, X.Shbou, Operator.. certlfleauon: This well was oomtructed under in,, direct supervision. Materials used and ia4ormetlon reported above are true to may beat knowledge and belief. - [Signed] -.....R.D m ahli� Gam_ ..—.._ Dategon Drilling Machine Operatods Ucense 1Pa....._.Z$fi_........._..._..— Water well contraotwt cormse res: This well was drilled order my jurisdiction and this report 18 true to the beat a my knowledge and bebaf. Nava 4L.....0[.__ileill.i�n�..:8'wguap._�piiri.-s;�aii __...._ Address .2320 M fat cw.mr welt sen ( n4adue. License No. --264}. - Date .._8/23.— ... ......... , ipJt(. (pER .1imONAL BERETS . "Case.) apwesaw _STATE OFOREGON tat Mit / &J C—�// btsOut hyOM WELLREPO ( J GCrCJ (ffi regnia@d hyo%53].]65@OAR 690-2f049 5v SEP -81994 scan cava# 1,1- ctloa➢for len Wlere art are oa Nelast of thkf (1) OWWR/P1tOSECT. _ wec}.HD. W, c:HI (6)40.C&VQN OFWELLBy legal/dea�rlptioa OF RK: g/r z MOer Strekt address ofwel "o0 7 a1I—».....vF New wvomclibv E] Aaeredhh (Repair76emod'ihon) - pr Tarlotnu uofwalacfldov�y ❑Covvuaidv ❑D evinB' RLAboosl evt 3. A1"GICHMAP LOCATIONMENTH+MD. blapslullioslso& eppswdmese sale aad nook arrow. ❑ RMKYry ❑ Bmary Mud [Cable- _ -- :d FLbelowlavdemfaw. care v• _ 17 Hallow St Mgo, ❑ 0ther _ - A oo Aesosoo - Ib/%.. i Due _ BORE HOLE CONSTRUCTION (S) WATER BEARING ZONES: % D� 1&s No _ Deptlratwhiebwuerwaafert Eau.a 'el Stm�dmds ❑ � D"eplM1 ofwmpleRdwe6 �%J � ft _. 'ib 4 aw am Lava amfue /o r / � 9 D. water-dghrcvvm e —Soh eflosh vault LA. a �� (9)WELLLOG: croaaaelevv oa _ - a�9. P(�U: dienmter � nda .. Pmm ib swL ���� matmial Threaaea cotta • 11 El Seat�4:"9: Liver / D A�?99' P.. Db,99'•R.., mateum q:6'N.: e4:0'.'tl: WElded Theadat cb iw. Fo 9 ,9dn: 4a?;: Matt�al nmvnot Qi:a'-4,_.. Rry Gmut weigh 0 .APs.. ,i�d: AbPPp eb.• : Bevtov'nep�at least3ft Wick —screw ., ... uy. FilterQ'd p4q osaboisl pack nbo _ rare, a%a -�. sla sea hL v rwp Material Size (5) WELLTESM _ _ ❑Pump ❑Bailer- _ ❑ Ah, ❑Flowwg Artatm_ _ Permeahaity dela DPM__ -__ 1 pooofwara Depth mm.=:e.. now mood ft Was watersaalyaisP No By wnomR - Depthofstrdatobemdyzed. Fro dto ft rsamc lYnhaua�I�'I4viror VkLL Covswctor Certifiradm: / larafy Nat slit work I performed u¢the wvshacGan, alteretloq m atievdoomen[ oftial web ie h complianw with Oregon well wq-the s�dards. Muerials used avd'u adoo ttported above are -smshe ben knowledge ev bag AdWCNambea > Signed � �., ale (boaded)Muviwr likLL C1maWctor aalifuatio�e I accept msponsibtliry for the covehucaoq eltmetlon, or abuWmiment eroh performM ov tnia weLL aadvg Wa wuumcdov aa[es mporma above. ALL ,m& ma TT503-620-7892 m_INC eLu - § 2 oil h m.ssu va, � 5 tea' z Q 1-1 g!\ LL z-!dd- IL \ \ \9® G!#!2 « # \ g,q = se plGb,e,99 a a@ 2 g4 R w Q d e / E § .,,.::\ /I /■ 0. 4«00•+:,,�� / E Soil Map—Lane County Area, Oregon Map Unit Legend 812 G Street Natural Resources Web Sail Survey 11/102012 Conservation Service National CCOperstive Soil Surrey Page 3013 Map Unit Symbol Map Unit Name Acin a In AOI Percent of AOI 76 Malabon-Urban land complex 1.0 100.0% Totals far Area of Interest 1-0 100.0% Natural Resources Web Sail Survey 11/102012 Conservation Service National CCOperstive Soil Surrey Page 3013 Map Unit Desorption : Malabon-UNan land connplax--Lane County Area, Oregon Lane County Area, Oregon 76—Malabon-Urban land complex Map Unit Setting National map unit symbol: 238t Elevation: 300 to 650 feet Mean annual precipitation: 40 to 60 inches Mean annual air temperature: 52 to 54 degrees F Frost -free period. 165 to 210 days Farmland classification: Farmland of statewide importance Map Unit Composition Malabon and similar soils: 50 percent Urban land: 45 percent Estimates are based on observations, descriptions, and transects of the mapumt. Description of Malabon Setting Landform: Terraces Landform position (three-dimensional): Tread Down-slope shape: Linear Across -slope shape: Linear Parent material. Silty and clayey alluvium Typical profile Hl - 0 to 12 inches: silty clay loam H2 - 12 to 42 inches: silly clay H3 - 42 to 60 inches: clay loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): Moderately high (0.20 to 0.57 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water supply, 0 to 60 inches. High (about 11.4 inches) Interpretive groups Land capability classification (irrigated): 1 Land capability classification (nonirrigated): 1 Hydrologic Soil Group: C Ecological site: R002XC006OR - Stream Terrace Group Forage suitability group: Well drained < 15% Slopes (GO02XY0020R) Other vegetative classification: Well drained < 15% Slopes (GO02XY0020R) 812 G street ibM Natural Resources Web Soil Surrey 11/1 M022 i Conservation Service National Cooperative Soil Surrey Page 1 of 2 Map Unit Desorption: Malabon-Urban land complex—Lane County Area, Oregon Hydric soil rating: No Description of Urban Land Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): S Hydric soil rating: No Data Source Information Soil Survey Area: Lane County Area, Oregon Survey Area Data: Version 20, Sep 14, 2022 812 G sheet Ibnt Natural Resources Web Soil Survey 11/1612022 �I Conservation Service National Cooperative Soil Survey Page 2 of 2