DENVER ZOODENVER ZOO Lion’s QuartersLion’s Quarters

Recycle Cross-connectionRecycle Cross-connection

Fred J. SanchezFred J. Sanchez

Denver Water, Water Quality Denver Water, Water Quality Investigations SupervisorInvestigations Supervisor

AGENDAAGENDA

CROSS-CONN @ THE DENVER CROSS-CONN @ THE DENVER ZOOZOO RECYCLE SYSTEM OVERVIEWRECYCLE SYSTEM OVERVIEW BACKGROUND INFORMATIONBACKGROUND INFORMATION INCIDENT DESCRIPTIONINCIDENT DESCRIPTION ACTIONS TAKENACTIONS TAKEN INVESTIGATION RESULTSINVESTIGATION RESULTS CORRECTIVE MEASURESCORRECTIVE MEASURES

AcknowledgmentsAcknowledgments

Water Quality PersonnelWater Quality Personnel WQ Investigations WQ Investigations Cross-connections Cross-connections

Water Control PersonnelWater Control Personnel Emergency ServicesEmergency Services System QualitySystem Quality

Denver Zoo PersonnelDenver Zoo Personnel VP for PlanningVP for Planning Zoo StaffZoo Staff

My personal friend…My personal friend…

DENVER WATER’SDENVER WATER’S RECYCLE SYSTEM RECYCLE SYSTEM

Metro WastewaterMetro Wastewater Reclamation provides Reclamation provides Denver Water’s Recycle Plant with source Denver Water’s Recycle Plant with source waterwater

The source is further The source is further treatedtreated by Denver Water by Denver Water Biological NitrificationBiological Nitrification Chemical CoagulationChemical Coagulation FlocculationFlocculation Granular Media FiltrationGranular Media Filtration Chlorine DisinfectionChlorine Disinfection

DW provides both potable & recycled water to DW provides both potable & recycled water to the Denver Zoothe Denver Zoo

DENVER ZOO’S RECYCLE DENVER ZOO’S RECYCLE SYSTEMSYSTEM

Takes recycled water from Denver Takes recycled water from Denver Water’s Recycling Distribution Water’s Recycling Distribution System System

Supplied by the Zoo’s Pump StationSupplied by the Zoo’s Pump Station Owned & Operated by the ZooOwned & Operated by the Zoo

Primary use…Primary use… Wash Down purposes in the animal pensWash Down purposes in the animal pens

DENVERDENVER WATER’S RECYCLE SYSTEM PHASE I MAPWATER’S RECYCLE SYSTEM PHASE I MAP

DENVERDENVER ZOOZOO

METROMETRO WASTE WATERWASTE WATERDWDW RECYCLERECYCLE PLANTPLANT

LNQ’S BACKGROUND LNQ’S BACKGROUND INFORMATIONINFORMATION

Both Potable & Recycle lines are located Both Potable & Recycle lines are located in the LNQ’S Mechanical Roomin the LNQ’S Mechanical Room The potable & recycle water entering the The potable & recycle water entering the

mechanical room have separate servicesmechanical room have separate services PotablePotable is used for animal food prep, employee is used for animal food prep, employee

wash room, and hose bibs.wash room, and hose bibs. RecycleRecycle is primarily used for wash down purposes is primarily used for wash down purposes

in the Lion’s holding quarters since May 2005.in the Lion’s holding quarters since May 2005.

LNQ’S RECYCLE & POTABLE LNQ’S RECYCLE & POTABLE SYSTEMSYSTEM

RECYCLE LINERECYCLE LINE

LION’S WASH-DOWN LINELION’S WASH-DOWN LINE

POTABLE SERVICE POTABLE SERVICE WATERWATER

PHYSICAL SEPARATIONPHYSICAL SEPARATION

INCIDENT DESRIPTIONINCIDENT DESRIPTION

February 27, 2006February 27, 2006 DW scheduled a DW scheduled a meetingmeeting with Zoo staff with Zoo staff Discuss a means of Discuss a means of temporarilytemporarily supplying the supplying the

Zoo’s recycle system with potable waterZoo’s recycle system with potable water Accommodate recycle system constructionAccommodate recycle system construction

Conceptual PlanConceptual Plan Physically disconnectPhysically disconnect the ‘recycled source’ at the ‘recycled source’ at

LNQLNQ 2-Inch Diameter Pipe2-Inch Diameter Pipe Cut & CapCut & Cap

ConnectConnect the ‘potable line’ as the new source the ‘potable line’ as the new source protected by a Reduced Pressured Zoned protected by a Reduced Pressured Zoned Backflow Prevention Device Backflow Prevention Device (RPZ)(RPZ)

INCIDENT...INCIDENT...

During the meeting on Feb 27During the meeting on Feb 27thth DW discovered the DW discovered the conversionconversion was was done done

incorrectlyincorrectly A direct A direct “Cross-connection”“Cross-connection” between the between the

potable & recycled water lines was potable & recycled water lines was createdcreated

The Zoo’s pump station was operating The Zoo’s pump station was operating during the discoveryduring the discovery

CROSS-CONNECTIONCROSS-CONNECTION

RECYCLE LINERECYCLE LINE

CROSS-CONNECTIONCROSS-CONNECTION

POTABLE SERVICE WATERPOTABLE SERVICE WATER

ACTIONS TAKENACTIONS TAKEN

Denver Water Personnel & Zoo Denver Water Personnel & Zoo Personnel Personnel surveyedsurveyed the potable the potable system for system for contaminated contaminated drinking drinking water (Recycle)water (Recycle)

Used Used Specific ConductanceSpecific Conductance Meters Meters ((µS)µS) Potable Source = Potable Source = 300 300 µSµS Recycle Source = Recycle Source = 700 – 900 µS700 – 900 µS

ACTIONS…ACTIONS…

Utilized Zoo’s Engineering Drawings Utilized Zoo’s Engineering Drawings & Tested Conductivity& Tested Conductivity Fire HydrantsFire Hydrants Water FountainsWater Fountains Sink TapsSink Taps Potable Water Service LinesPotable Water Service Lines DW’s Distribution SystemDW’s Distribution System

Outside Zoo’s propertyOutside Zoo’s property

ACTIONS…ACTIONS…

Collected Collected bacteriological bacteriological samplessamples Drinking Fountains Drinking Fountains Break Room TapsBreak Room Taps Food VendorsFood Vendors

PendingPending the the bacteriological bacteriological resultsresults DW recommended isolating the Zoo’s systemDW recommended isolating the Zoo’s system Prevent public contact with the drinking water Prevent public contact with the drinking water

until further notice until further notice No Human ConsumptionNo Human Consumption

INVESTIGATION RESULTSINVESTIGATION RESULTS

The The conductivityconductivity results showed results showed Small portion of the Small portion of the Zoo’s potable Zoo’s potable

systemsystem was was contaminatedcontaminated with with Recycle Recycle waterwater

LNQ’s Domestic Service LineLNQ’s Domestic Service Line 3-inch diameter x 345-ft3-inch diameter x 345-ft

Zoo’s Distribution Main Zoo’s Distribution Main Service to the LNQ bldg.Service to the LNQ bldg. 8-inch diameter x 30-ft8-inch diameter x 30-ft

Zoo's POTABLE DISTRIBUTION SYSTEMZoo's POTABLE DISTRIBUTION SYSTEM

CONTAMINATED SERVICECONTAMINATED SERVICE

CONTAMINATED CONTAMINATED SERVICE LINE & WATER MAINSERVICE LINE & WATER MAIN

CORRECTIVE MEASURESCORRECTIVE MEASURES

RemoveRemove the the Cross-connectionCross-connection between the between the Potable & Potable & RecycleRecycle Line LinePhysically separate the two Physically separate the two systemssystems

APPROVED PHYSICAL SEPARATIONAPPROVED PHYSICAL SEPARATION

RECYCLE LINERECYCLE LINE

APPROVED SEPARATIONAPPROVED SEPARATION

POTABLE SERVICE WATERPOTABLE SERVICE WATER

CORRECTIVE MEASURES…CORRECTIVE MEASURES…

Flush, Disinfect, Test Contaminated Flush, Disinfect, Test Contaminated Service Lines & Distribution Water Service Lines & Distribution Water MainMain Ozonation Method = 1.0 mg/L DosageOzonation Method = 1.0 mg/L Dosage

Kills Pathogenic OrganismsKills Pathogenic Organisms Kills CryptosporidiumKills Cryptosporidium

Collected Bacteriological SamplesCollected Bacteriological Samples Service LinesService Lines Distribution System Fire HydrantDistribution System Fire Hydrant

CORRECTIVE MEASURES…CORRECTIVE MEASURES…

Ensure the Zoo complies with Recycle Ensure the Zoo complies with Recycle Water RegulationsWater Regulations Backflow PreventionBackflow Prevention Marking & SignageMarking & Signage

Create a Management of Change Create a Management of Change ProtocolProtocol Ensure Zoo staff & contractors have approval for Ensure Zoo staff & contractors have approval for

future modificationsfuture modifications Provide additional training to Zoo staffProvide additional training to Zoo staff

Regulations RequirementsRegulations Requirements Protect the public water system from Protect the public water system from

contaminationcontamination

CONCLUSIONCONCLUSION

The Cross-connection was removedThe Cross-connection was removed All bacteriological results from the All bacteriological results from the

initial water quality survey were initial water quality survey were negativenegative

All bacteriological results from All bacteriological results from disinfection process were negativedisinfection process were negative

The Zoo has The Zoo has “High Quality H“High Quality H220”0”

Most Important…Most Important…

MOST IMPORTANTMOST IMPORTANT

KEEP FRED’S FRIENDS LOCKED UP KEEP FRED’S FRIENDS LOCKED UP

““AT ALL TIMES”!AT ALL TIMES”!

Q&AQ&A??