City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

Cyanide Attenuation StudyCyanide Attenuation Study

Use of TraceUse of Trace--Level Cyanide Method Level Cyanide Method to Determine Attenuation of to Determine Attenuation of

Discharged Cyanide in Lower South Discharged Cyanide in Lower South San Francisco BaySan Francisco Bay

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

…although the origins of terrestrial life appear to have been dependent in part on the presence and chemical reactivity of HCN and its derivatives, paradoxically it is toxic to the majority of living matter (Timothy C. Marrs and Bryan Ballantyne)

Paradox

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

Regulatory Driver for StudyRegulatory Driver for Study

•• EPA Cyanide Criterion is 1.0 EPA Cyanide Criterion is 1.0 μμg/Lg/L•• Proposed S. F. Bay SSO is 2.9 Proposed S. F. Bay SSO is 2.9 μμg/Lg/L•• Most ShallowMost Shallow--Water Dischargers cannot Water Dischargers cannot

meet this limitmeet this limit

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

Compliance StrategiesCompliance Strategies•• WaterWater--Effect Ratio study: results Effect Ratio study: results ≅≅ 11•• Spiking studySpiking study•• Translator StudyTranslator Study

–– Free:Total cyanideFree:Total cyanide–– EPA criteria based on free cyanideEPA criteria based on free cyanide–– MDL for free cyanide too highMDL for free cyanide too high

•• Fate and transport studyFate and transport study–– Need trace total cyanide methodNeed trace total cyanide method

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

Attenuation StudyAttenuation Study

•• F & T Most Reasonable Strategy for ReliefF & T Most Reasonable Strategy for Relief–– Attenuation = dilution + degradationAttenuation = dilution + degradation

•• Based on low levels of Total CyanideBased on low levels of Total Cyanide•• Need Lower Reporting LimitNeed Lower Reporting Limit•• Another type of Another type of ““TranslatorTranslator””

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

Trace Cyanide Method Trace Cyanide Method DevelopmentDevelopment

•• MDL for conventional method : 1MDL for conventional method : 1--2 2 μμg/Lg/L•• Proposed SSO requires MDL of < 0.5 Proposed SSO requires MDL of < 0.5 μμg/Lg/L•• Trace method adapted from Standard Trace method adapted from Standard

Methods, 18Methods, 18thth editionedition-- 4500 CN4500 CN--B,C &EB,C &E

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

Method ModificationsMethod Modifications

•• Concentration Factor increased from two Concentration Factor increased from two to six foldto six fold

•• Increased distillation timeIncreased distillation time•• Use of a 10 cm Cell for color Use of a 10 cm Cell for color

determinationdetermination•• Use of Nitrogen as a carrier gasUse of Nitrogen as a carrier gas

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

MethodologyMethodology

•• Preliminary Treatment of samplesPreliminary Treatment of samples–– to remove interferencesto remove interferences

•• DistillationDistillation–– to liberate cyanide as gaseous HCN from the to liberate cyanide as gaseous HCN from the

matrix background. HCN is collected as CNmatrix background. HCN is collected as CN-- in in the NaOH scrubbing solutionthe NaOH scrubbing solution

•• Colorimetric Determination of CyanideColorimetric Determination of Cyanide–– UVUV--VIS SpectrophotometerVIS Spectrophotometer

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

Distillation ApparatusDistillation Apparatus

•• Heating MantlesHeating Mantles•• Distillation FlasksDistillation Flasks•• Cold Finger Cold Finger

CondenserCondenser•• SpargerSparger•• Sparger VesselSparger Vessel•• Nitrogen GasNitrogen Gas

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

Distillation ProcedureDistillation Procedure

•• Sample Volume: 700 mlSample Volume: 700 ml•• Reagents: Reagents:

70 ml 0.04N NaOH 70 ml 0.04N NaOH PbCO3PbCO3MgCL2, NH2SO3HMgCL2, NH2SO3HH2SO4H2SO4Spikes: 2Spikes: 2--5ug/L (1ug/ml std) KCN5ug/L (1ug/ml std) KCNNitrogen Flow Rate Nitrogen Flow Rate

22--4 air bubbles/sec4 air bubbles/sec

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

MDL StudiesMDL Studies

MatrixMatrixDistilled Distilled WaterWater

Final Final EffluentEffluent SeawaterSeawater

MDLMDL((μμg/L)g/L) 0.060.06 0.20.2 .06.06

PQLPQL((μμg/L)g/L) 0.30.3 1.01.0 0.30.3

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

Cyanide RecoveriesCyanide Recoveries

0

20

40

60

80

100

120

140

9/22/200310/12/200311/1/200311/21/200312/11/200312/31/20031/20/20042/9/20042/29/20043/20/20044/9/20044/29/20045/19/20046/8/2004

Date

Perc

ent R

ecov

ery

0

5

10

15

20

25

30

35

40

45

50

Rel

ativ

e Pe

rcen

t Diff

eren

ce

Blank Spike Blank - Low & High Matrix Spike Matrix - Low & High % RPD

Mean = 93.3 Mean = 81.4

Mean = 6.1

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

Holding Time ExperimentsHolding Time Experiments

0.0

2.0

4.0

6.0

8.0

10.0

12.0

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Days Held Prior to Aalysis

Tota

l Cya

nide

( μg/

L)10 ppb CN-spiked DI 10 ppb CN-spiked DI + NaOH FE + NaOH FE Seawater

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

Effect of NaOH PreservationEffect of NaOH Preservation

0

2

4

6

8

10

12

1 2 3Plant Effluent

Tota

l Cya

nide

μg/

LWithout NaOH With NaOH

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

Cyanide Recoveries in Raw SewageCyanide Recoveries in Raw Sewage

Spike Spike ConcConc((μμg/L)g/L)

Preserved Preserved K3Fe(CN)6 K3Fe(CN)6 % Recovery% Recovery

Unpreserved Unpreserved K3Fe(CN)6 K3Fe(CN)6 % Recovery% Recovery

55 73.673.6 80.280.2

1010 74.374.3 81.681.6

2020 81.981.9 87.887.8

5050 66.866.8 84.384.3

Average Average RecoveryRecovery

74.274.2 83.583.5

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

Cyanide Recoveries in Raw SewageCyanide Recoveries in Raw Sewage

•• Recoveries : Independent of Spike ConcentrationRecoveries : Independent of Spike ConcentrationHigher with K3Fe(CN)6 than KCNHigher with K3Fe(CN)6 than KCN

•• Average Recoveries with K3Fe(CN)6:Average Recoveries with K3Fe(CN)6:-- 74.2% Preserved74.2% Preserved-- 83.5% Unpreserved83.5% Unpreserved

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

Future ResearchFuture Research

•• Cyanide Speciation Studies Cyanide Speciation Studies –– Free CyanideFree Cyanide•• Sample Preservation IssuesSample Preservation Issues•• Cyanide Formation:Cyanide Formation:

-- ChloraminationChloramination-- ThiocyanateThiocyanate

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

Plant Cyanide MeasurementsPlant Cyanide Measurements

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

Plant Influent (RawSewage)

NitrificationEffluent

Plant Final Effluent

Plant Location

Mea

n To

tal C

yani

de ( μ

g/L

+ s.

d.)

* *1.5

2.7

1.8

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

Plant Variability StudyPlant Variability Study

0.0

0.5

1.0

1.5

2.0

2.5

3.0

0100 0400 0700 1000 1300 1600 1900 2200

Time

Tota

l Cya

nide

( μg/

L)2/17/2004 2/18/2004 2/19/2004

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

Cyanide Sampling StationsCyanide Sampling Stations

km0 2.5

SB08SB08SB08SB08SB08SB08SB08SB08SB08SB08

SB01SB01SB01SB01SB01SB01SB01SB01SB01SB01

SB09SB09SB09SB09SB09SB09SB09SB09SB09SB09

SB10SB10SB10SB10SB10SB10SB10SB10SB10SB10

SB02SB02SB02SB02SB02SB02SB02SB02SB02SB02

SB06SB06SB06SB06SB06SB06SB06SB06SB06SB06

SB07SB07SB07SB07SB07SB07SB07SB07SB07SB07

5

SB03SB03SB03SB03SB03SB03SB03SB03SB03SB03

SB05SB05SB05SB05SB05SB05SB05SB05SB05SB05

SB14SB14SB14SB14SB14SB14SB14SB14SB14SB14

SB12SB12SB12SB12SB12SB12SB12SB12SB12SB12

SB04SB04SB04SB04SB04SB04SB04SB04SB04SB04SB13SB13SB13SB13SB13SB13SB13SB13SB13SB13

SB15SB15SB15SB15SB15SB15SB15SB15SB15SB15

SB11SB11SB11SB11SB11SB11SB11SB11SB11SB11

OutfallOutfall

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

Cyanide AttenuationCyanide Attenuation

0.0

1.0

2.0

3.0

4.0

5.0

Final EffluentSB15SB14SB13SB04SB05SB03SB06SB02SB08SB10SB07SB09SB01SB11SB12

Cyanide stations going away from the Plant

Mea

n C

yani

de (

μg/

L +

s.d.

)

Proposed Site-Specific Objective (red line)

7 9 9

10

Station SB11 is Upstream of Plant

Station SB12 is in Alviso Slough

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

Cyanide Attenuation FactorsCyanide Attenuation Factors

Date Tidal Cycle

SB04 Cyanide Concentration*

SB05 Cyanide Concentration*

Final Effluent Cyanide

Concentration*

SB04 Attenuation

Factor

SB05 Attenuation

Factor

7/9/03 Flooding 1 0.4 1.6 1.6 4.08/20/03 Flooding 0.8 0.6 1.8 2.3 3.09/24/03 Flooding 1.2 0.5 3.5 2.9 7.0

10/15/03 Ebbing 1.8 0.9 2.3 1.3 2.611/19/03 Flooding 0.7 0.2 2.7 3.9 13.512/3/03 Ebbing 0.7 0.4 5.2 7.4 13.01/21/04 Flooding 1.1 0.4 1.8 1.6 4.52/27/04 Ebbing 0.9 0.7 2 2.2 2.93/17/04 Flooding 0.8 0.3 3.1 3.9 10.34/16/04 Flooding 1.7 0.4 4.7 2.8 11.86/23/04 Ebbing 1.3 0.8 2.5 1.9 3.1

Mean 2.9 6.9* Concentration: μg/L Median 2.3 4.5

n 11 11

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

Cyanide IncidentCyanide Incident

0

10

20

30

40

50

60

NE FE SB15SB14SB13SB 04SB 05SB 03SB 06SB 02SB 08SB 10SB 07SB 09SB 01

Cyanide Stations going away from the Plant

Cya

nide

Con

cent

ratio

n ( μ

g/L)

Proposed SSO = 2.9 μg/L

Coyote CreekStation nearest to Plant

City of San JoseCity of San JoseEnvironmental Services DepartmentEnvironmental Services Department 2006 NWQMC Presentation2006 NWQMC Presentation

Report available at:

http://www.sanjoseca.gov/esd/pub_res.htm

Cyanide Attenuation Study

Watershed Investigations

and

Laboratory Staff

Watershed Protection Group

Environmental Services Department

City of San Jose

September 1, 2004