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Home My WebLink About13 Discharge EstimationPollution plume Estimates,"'.-m-i OM Why add Volume�Estiniates-to 10 ome sirriates are Y[ Irivestigation. t Who is looking at us? • North Carolina Division of Water Resources • Environmental Protection Agency • City of Durham Residents • City of Durham Audit Services • City of Durham Water Management • City of Durham —Upper' Management • City of Raleigh • US Army Corp of Engineers (USAGE) • Non -government (ECWA) • Who else? Goal: Estimate total volume of pollutants that enter the MS4 What can we reasonably Estimate? 1) Private SSO —residential clean out? Broken Pipes? 2) Public SSO (Water Management may provide an estimate) 3) Mobile/Fixed car washes 4) Restaurant Grease 5) Paint/brush washing 6) Fuel/Hydraulic oil spills 7) Others? - .3 � Dur-.ion X FlowAft/second)..,.. _ � r i } 4 As Y. Mir., Duration =� '. 4► Need Start and Stop time, P= - Start time can be the most difficult to determine + DO NOT USE Initial notification time - Witness statements, Knock on doors, Telemetry alarms?, Ask Questions � s r Stop time should be accurately recorded by one of US! -f - Duration X FJOW(ft3/second) Total Volume Flow A" Float method Flow = Velocity x Area Curb Sewage i Gutter ° , fj - -_ 1Md1h Multiply average depth times stream width to determine crass -sectional area I gawnstream y! � 1 Take incremental depth measurements to determine average depth Start float well upstream from timing zone Float �w Time float over distance of about ■ 70 feet Duration X FJOW(ft3/second) = Total Volume Flow Float method b_ Flow = Velocity x Area Velocity? = distance X time , Curb Sewage i Gutter I Depth 1Mda Multiply average depth times stream width to determine crass -sectional area I Dawnstream y! � 1 Take incremental depth measurements to determine average depth Start float well upstream from timing zone Float �w Time float over distance of about ■ 70 feet Duration X FJOW(ft3/second) = Total Volume Flow Float method b_ Flow = Velocity x Area 5 feet in 150 seconds Curb Sewage i Gutter I Depth 1Mda Start float well upstream from timing zone Multiply average depth ,uI times stream width to determine crass -sectional area Float Downstream w Time float over ■ I — -� distance of about Take incremental depth measurements to determine average depth 10 feet Duration X FJOW(ft3/second) = Total Volume Flow Float method b_ Flow = Velocity x Area 5 feet in 150 seconds 5/150 = 0.033 feet per second Curb Sewage Gutter I Depth 1Mda Start float well upstream from timing zone Multiply average depth ,uI times stream width to determine crass -sectional area Float Downstream w Time float over ■ I — -� distance of about Take incremental depth measurements to determine average depth 10 feet Duration X FJOW(ft3/second) = Total Volume Flow 4' Float method Flow = Velocity x Area - Area? AB/2 = Area of Triangle A&B Triangle legs Curb Sewage Gutter I Wldfh i Start float well upstream from timing zone Multiply average depth ,uI times stream width to determine crass -sectional area Float V� Downstream w Time float over ■ I — -� distance of about Take incremental depth measurements to determine average depth 10 feet Duration X FJOW(ft3/second) = Total Volume Flow ......... Float method Flow = Velocity x Area - (0.5)6 / 2 = 1.52 inches 0.1252 feet Curb Sewage Glilt9r Depth ` V �� 1Nldfh Start float well upstream from timing zone Multiply average depth ,uI times stream width to determine crass -sectional area Float Downstream w Time float over ■ I — -� distance of about Take incremental depth measurements to determine average depth 10 feet Duration X FJOW(ft3/second) = Total Volume Flow ......... Float method Flow = Velocity x Area - 0.033 X 0.125 = 0.004 ft3/sec r. . Curb Sewage Gutter I With Start float well upstream from timing zone Multiply average depth ,uI times stream width to determine crass -sectional area Float Downstream w Time float over ■ I — -� distance of about Take incremental depth measurements to determine average depth 10 feet Duration X FJOW(ft3/second) = Total Volume Flow ......... Float method Flow = Velocity x Area - 0.033 X 0.125 = 0.004 ft3/sec Duration? Curb Sewage Gutter I With Start float well upstream from timing zone Multiply average depth ,uI times stream width to determine crass -sectional area Float Downstream w Time float over ■ I — -� distance of about Take incremental depth measurements to determine average depth 10 feet Duration X Flow(ft3/second) =Total Volume Flow �••� • �: _�1 � -'-ram' r y �- Bucket collection How fast does it fill up?_ _n i.z a %av If a 5 Gallon Bucket was full in 5 minutes what is the flow? r PW- : Duration X Flow(ft3/second) =Total Volume Flow �••� • �: _�1 � -'-ram' r y �- Bucket collection How fast does it fill up?_ _n i.z a %av If a 5 Gallon Bucket was full in 5 minutes what is the flow? r Volume/Time = Flow 5 Gallons/5 Minutes = 1 Gallon per minute IF �- If Duration is 2 hours what is the TOTAL Volume?rs; . w Duration X Flow(ft3/second) =Total Volume Flow Bucket collection How fast does it fill up? If a 5 Gallon Bucket was full in 5 minutes what is the flow? 5 Gallons/5 Minutes = 1 Gallon per minute If Duration is 2 hours what is the TOTAL Volume? 1 Gallon (per minute) X 120 minutes (2 hours) _ 120 Gallons Duration-k-Row(ft -eco,dyunye Length X Width = Area What is the Depth?Afto -.z pia How do we get Volume? • M r Ar dr fl t tim it f r me r d easu a ea, op a oa , e o a asu e distance Find a storm drain, pull the grate, use bucket metho •o • 5.3 Gallons or 20 Liters per car — Mobile Car wash study _ • How many cars have yo,Tu washed today? " - _ =,' �`y ' � - - - ` s '-f Z � � .L'i ram.. ..�-.f'n,. •r`_.. �i+�'" : - - - City of San Diego Metropolitan Wastewater Department 100 gpm Reference Sheet for Estimating Sewer Spills from Overflowing Sewer Manholes All estimates are calculated in gallons per minute (gpm) 25 gpm 150 gpm 225 gpm 250 gpm Wastewater Collection Division (619) 654-4160 50 gpm 200 gpm �275 gpm Tom.. Courtesy of the Ohio EPA: Sewage Flow Rate Estimates Duration is still needed to calculate Volume! Find this document: F:\SW\Division Fi Ies\Qua I ity\Docs\I nvestigati ons\Investigation and Enforcement Training Attachment B ESTIMATING SEWAGE FLOW RATE These estimated flows are empirical and are intended for estimating average flow rates ESTIMATED SEWAGE FLOW PLACE (Gallons Per Day) Apartments 250 one -bedroom 300 two- bedroom 350 three -bedroom Assembly Halls' 2 per seat Beauty Shop, Styling Salon 200 per basin Bowling Alleys (no food service)' 75 per lane Churches (small)' 3-5 per sanctuary seat Churches (large with kitchen)b 5-7 per sanctuary seat Country Clubs 50 per member Dance Halls' 2 per person Doctors/Dentists 75 per doctor 20 per employee 10 per patient Drive -Inn Theaters 5 per car space Factories (no showers) 25 per employee Factories (with showers) 35 per employee Food Service Operations Ordinary Restaurant (not 24-hour) 35 per seat at 400 ppm BOD5 24-Hour Restaurant 50 per seat at 400 ppm BODS Banquet Rooms 5 per seat at 400 ppm BODS Restaurant Along Freeway 100 per seat at 400 ppm BODS Tavern (very little food service) 35 per seat at 400 ppm BODS Curb Service (drive-in) 50 per car space at 400 ppm BODS Vending Machine Restaurants 100 per seat at 200 ppm BODS Homes in Subdivision 400 per dwelling Hospitals (no resident personnel)' 300 per bed Other Estimates • Private SSO — See Ohio EPA guidance • Public SSO (Water Management may provide an estimate) • Mobile/Fixed car washes (5.3 Gallons or 20 Liters per car — Mobile Car wash study) • Restaurant Grease — area X depth measurement (Hopefully its not flowing!) • Paint/brush washing - ??? Some measurement will be necessary • Hydraulic oil spills — ALL heavy equipment will have total volume for hydraulic fluid in operators/maintenance manual. Fleet has LOTS of data on this! • Fuel Spills — How many gallons does the tank/container hold? How full was it before the spill? How full is it now? • Surface washing — How many gallons does the reservoir hold? How many times have you filled it up? What is the flow rate of the pressure washer being used? How long have you been washing ?