LOW LEVEL EFFLUENT LIMITATIONS:LOW LEVEL EFFLUENT LIMITATIONS:IS IT MBR, MEMBRANE FILTRATION, IS IT MBR, MEMBRANE FILTRATION,

TWO STAGE FILTRATION OR TWO STAGE FILTRATION OR CONVENTIONAL TERTIARY TREATMENT?CONVENTIONAL TERTIARY TREATMENT?

Presented byPresented by

Onder Caliskaner, Ph.D., P.E.Onder Caliskaner, Ph.D., P.E.Project Manager, Kennedy/Jenks ConsultantsProject Manager, Kennedy/Jenks Consultants

Brian Davis, P.E.Brian Davis, P.E.Project Manager, Kennedy/Jenks ConsultantsProject Manager, Kennedy/Jenks Consultants

Presented at thePresented at theCWEA Sacramento Section Meeting CWEA Sacramento Section Meeting

December 13, 2006December 13, 2006

LINDA COUNTY WATER DISTRICTLINDA COUNTY WATER DISTRICT

Located in Yuba County, south of Marysville Provides water and sewer service to over 12,000 customersServes primarily residential and light commercialRural community experiencing rapid growth due to new development

LINDA COUNTY WATER DISTRICT LINDA COUNTY WATER DISTRICT WWTPWWTP

Plant constructed in 1962 with land disposal and permitted river discharge.Secondary level plant with trickling filter, primary and secondary clarification andchlorination/de-chlorination.Capacity to treat average dry weather flow of 1.8 MGD.

DISTRICTDISTRICT’’S STRATEGY FOR S STRATEGY FOR EFFLUENT DISPOSALEFFLUENT DISPOSAL

In 2004, the RWQCB requested that the District abandon their disposal ponds. The District weighed its alternatives:

Land disposal at new siteUse District’s permitted NPDESdischarge to riverRetain usage of existing ponds

After extensive engineering and cost analyses, the best option was found to be the continued use of the NPDES discharge.

LINDA COUNTY WATER DISTRICT LINDA COUNTY WATER DISTRICT NPDESNPDESPERMIT RENEWAL PROCESSPERMIT RENEWAL PROCESS

Permit to Discharge to Feather River, administrated by the Central Valley Regional Water Quality Control Board (RWQCB)Existing NPDES permit was to expire in June 2005Report of Waste Discharge submitted November 2004

Reasonable Potential Analysis for CTR and SIP contaminantsMixing Zone Study for discharge to Feather River

Administrative Draft from RWQCB December 2005Continued discussion with RWQCB staff regarding:

Compliance timelinesAssimilative capacityVarious other requirements

NEW NEW NPDESNPDES PERMITPERMIT

Adopted by RWQCB on 22 September 2006Allowed for expansion from 1.8 MGD to 5.0 MGDRequired tertiary level treatment with plant expansionAllowed for a mixing zone to relax effluent requirements for contaminants based on human health criteriaAdded re-opener clauses to allow future consideration of aquaticlife-based criteriaRequired full compliance by 22 September 2011

HOW TO MEET REQUIREMENTS OF HOW TO MEET REQUIREMENTS OF NEW PERMITNEW PERMIT

Significant plant improvements requiredExpansion of capacity to 5.0 MGD average dry weather flowNew secondary and tertiary treatment processesPossible advanced treatment

Take it one step at a timeAddress issues we can confidently control, such as Ammonia, BOD, Turbidity, etc…After construction of the new plant, then we can see where we stand; further steps may require additional study and a permit re-opener rather than employing advanced/high level treatment options

CHANGE IN EFFLUENT LIMITATIONSCHANGE IN EFFLUENT LIMITATIONS

2.2240Total Coliform (MPN/100 ml)1---Nitrite (mg/l)

10---Nitrate + Nitrite (mg/l)1.22 / 1.80 (a)---Ammonia (mg/l)

< 2---Turbidity (NTU)1045TSS (mg/l)1045BOD (mg/l)

New PermitOld PermitMonthly Averages

(a) Summer Limit / Winter Limit

LINDA COUNTY WATER DISTRICT WWTP LINDA COUNTY WATER DISTRICT WWTP EXISTING TREATMENT PLANT SITE PLANEXISTING TREATMENT PLANT SITE PLAN

SECONDARY SECONDARY CLARIFIERCLARIFIER

PRIMARY PRIMARY CLARIFIERSCLARIFIERS

TRICKLING TRICKLING FILTERFILTER

INFLUENT INFLUENT PUMP PUMP

STATIONSTATION

GRIT GRIT REMOVALREMOVAL

ANAEROBIC ANAEROBIC DIGESTERSDIGESTERS

CHLORINE CHLORINE CONTACT CONTACT

BASINBASIN

SLUDGE SLUDGE DRYING BEDSDRYING BEDS

LINDA COUNTY WATER DISTRICT LINDA COUNTY WATER DISTRICT WWTPWWTPEXISTING SITE PLANEXISTING SITE PLAN

HEADWORKSHEADWORKS••Coarse screeningCoarse screening••Influent pump stationInfluent pump station••Medium screeningMedium screening••Grit chamberGrit chamber••20 % 20 % TSSTSS removalremoval••6 % 6 % BODBOD removalremoval

LINDA COUNTY WATER DISTRICT WWTP LINDA COUNTY WATER DISTRICT WWTP EXISTING SITE PLANEXISTING SITE PLAN

PRIMARY CLARIFIERPRIMARY CLARIFIER••6060--feet diameterfeet diameter••77--feet side water depthfeet side water depth••44 % TSS removal44 % TSS removal••16% BOD removal16% BOD removal

LINDA COUNTY WATER DISTRICT WWTP LINDA COUNTY WATER DISTRICT WWTP EXISTING SITE PLANEXISTING SITE PLAN

TRICKLING FILTERTRICKLING FILTER••110110--feet diameterfeet diameter••44--feet side depthfeet side depth••54% BOD removal (Trickling 54% BOD removal (Trickling Filter/Secondary Clarifier)Filter/Secondary Clarifier)••No significant Ammonia/ No significant Ammonia/ Nitrogen removalNitrogen removal

LINDA COUNTY WATER DISTRICT LINDA COUNTY WATER DISTRICT WWTPWWTPEXISTING SITE PLANEXISTING SITE PLAN

SECONDARY CLARIFIERSECONDARY CLARIFIER••7575--feet diameterfeet diameter••1414--feet side water depthfeet side water depth••59 % 59 % TSSTSS removalremoval

LINDA COUNTY WATER DISTRICT WWTP LINDA COUNTY WATER DISTRICT WWTP EXISTING SITE PLANEXISTING SITE PLAN

CHLORINATION/DECHLORINATIONCHLORINATION/DECHLORINATION••30 feet wide30 feet wide••100 feet long100 feet long••Average effluent 14 MPN/ 100 mlAverage effluent 14 MPN/ 100 ml

EVALUATED TERTIARY EVALUATED TERTIARY TREATMENT ALTERNATIVESTREATMENT ALTERNATIVES

Conventional secondary effluent filtration

Secondary effluent membrane filtration

Secondary effluent two-stage filtration

Membrane Bio-reactor

EFFLUENT WATER QUALITY OBJECTIVESEFFLUENT WATER QUALITY OBJECTIVES

0.50.50.55-10 (<5%)Daily Maximum<0.2 (95%)<0.2 (95%)<0.2 (95%)2Daily AverageTurbidity

(NTU)

11120Daily Maximum0.40.40.44Monthly AverageTSS (mg/l)20202020Daily Maximum10101010Monthly Average

BOD (mg/l)

MBRTwo StageFiltration

SecondaryEffluent

MembraneFiltrationConventionalParameter

EFFLUENT WATER QUALITY OBJECTIVESEFFLUENT WATER QUALITY OBJECTIVES

23232323Daily Maximum2.22.22.22.27-day MedianTC (MPN/

100 ml)

15151515Daily Maximum10101010Monthly AverageTN

(mg/l)

2222Daily Maximum1-1.8 (a)1-1.8 (a)1-1.8 (a)1-1.8 (a)Monthly AverageAmmonia

(mg/l)

MBRTwo StageFiltration

SecondaryEffluent

MembraneFiltrationConventionalParameter

(a) winter limit / summer limit

Membrane Bio-reactor

HeadworksHeadworks

Primary Primary SedimentationSedimentation

Activated Activated Sludge ProcessSludge Process

Secondary Secondary SedimentationSedimentation

Secondary Secondary Effluent Effluent FiltrationFiltration

DisinfectionDisinfection

TERTIARY TREATMENT ALTERNATIVESTERTIARY TREATMENT ALTERNATIVESFLOW DIAGRAMSFLOW DIAGRAMS

HeadworksHeadworks

Primary Primary SedimentationSedimentation

Activated Activated Sludge ProcessSludge Process

Secondary Secondary SedimentationSedimentation

Membrane Membrane FiltrationFiltration

DisinfectionDisinfection

HeadworksHeadworks

Primary Primary SedimentationSedimentation

Activated Activated Sludge ProcessSludge Process

Secondary Secondary SedimentationSedimentation

Secondary Secondary Effluent Effluent FiltrationFiltration

DisinfectionDisinfection

HeadworksHeadworks

Primary Primary SedimentationSedimentation

(Optional)(Optional)

Membrane BioMembrane Bio--ReactorReactor

DisinfectionDisinfection

Secondary Effluent Membrane Filtration

Two-stage FiltrationConventional

Membrane Membrane FiltrationFiltration

EVALUATED ACTIVATED SLUDGE EVALUATED ACTIVATED SLUDGE PROCESSES PROCESSES

Plug Flow Activated Plug Flow Activated Sludge SystemSludge System

EVALUATED ACTIVATED SLUDGE EVALUATED ACTIVATED SLUDGE PROCESSES PROCESSES

Plug Flow Activated Plug Flow Activated Sludge SystemSludge SystemOxidation DitchOxidation Ditch

EVALUATED ACTIVATED SLUDGE EVALUATED ACTIVATED SLUDGE PROCESSES PROCESSES

Plug Flow Activated Plug Flow Activated Sludge SystemSludge SystemOxidation DitchOxidation DitchSequencing Batch Sequencing Batch ReactorReactor

EVALUATED SECONDARY EFFLUENT EVALUATED SECONDARY EFFLUENT FILTRATION SYSTEMS FILTRATION SYSTEMS

Granular Bed FiltrationContinuous Backwash (Dynasand, Technasand)

EVALUATED SECONDARY EFFLUENT EVALUATED SECONDARY EFFLUENT FILTRATION SYSTEMS FILTRATION SYSTEMS

Granular Bed FiltrationContinuous Backwash (Dynasand, Technasand)Pulsed Bed (Hydroclear)

EVALUATED SECONDARY EFFLUENT EVALUATED SECONDARY EFFLUENT FILTRATION SYSTEMS FILTRATION SYSTEMS

Granular Bed FiltrationContinuous Backwash (Dynasand, Technasand)Pulsed Bed (Hydroclear)

Compressible Medium Filtration (Fuzzy Filter)

EVALUATED SECONDARY EFFLUENT EVALUATED SECONDARY EFFLUENT FILTRATION SYSTEMS FILTRATION SYSTEMS

Granular Bed FiltrationContinuous Backwash (Dynasand, Technasand)Pulsed Bed (Hydroclear)

Compressible Medium Filtration (Fuzzy Filter)

EVALUATED SECONDARY EFFLUENT EVALUATED SECONDARY EFFLUENT FILTRATION SYSTEMS FILTRATION SYSTEMS

Granular Bed FiltrationContinuous Backwash (Dynasand, Technasand)Pulsed Bed (Hydroclear)

Compressible Medium Filtration (Fuzzy Filter)

EVALUATED SECONDARY EFFLUENT EVALUATED SECONDARY EFFLUENT FILTRATION SYSTEMS FILTRATION SYSTEMS

Granular Bed FiltrationContinuous Backwash (Dynasand, Technasand)Pulsed Bed (Hydroclear)

Compressible Medium Filtration (Fuzzy Filter)Disk Filtration

Fully submerged (Cloth Disk Filter)

EVALUATED SECONDARY EFFLUENT EVALUATED SECONDARY EFFLUENT FILTRATION SYSTEMS FILTRATION SYSTEMS

Granular Bed FiltrationContinuous Backwash (Dynasand, Technasand)Pulsed Bed (Hydroclear)

Compressible Medium Filtration (Fuzzy Filter)Disk Filtration

Fully submerged (Cloth Disk Filter)

EVALUATED SECONDARY EFFLUENT EVALUATED SECONDARY EFFLUENT FILTRATION SYSTEMS FILTRATION SYSTEMS

Granular Bed FiltrationContinuous Backwash (Dynasand, Technasand)Pulsed Bed (Hydroclear)

Compressible Medium Filtration (Fuzzy Filter)Disk Filtration

Fully submerged (Cloth Disk Filter)Partially Submerged (Hydrotech)

EVALUATED SECONDARY EFFLUENT EVALUATED SECONDARY EFFLUENT FILTRATION SYSTEMS FILTRATION SYSTEMS

Granular Bed FiltrationContinuous Backwash (Dynasand, Technasand)Pulsed Bed (Hydroclear)

Compressible Medium Filtration (Fuzzy Filter)Disk Filtration

Fully submerged (Cloth Disk Filter)Partially Submerged (Hydrotech)

EVALUATED MEMBRANE FILTRATION EVALUATED MEMBRANE FILTRATION TECHNOLOGIES TECHNOLOGIES

Secondary Effluent Membrane Filtration

Hollow-Fiber (Zenon)

EVALUATED MEMBRANE FILTRATION EVALUATED MEMBRANE FILTRATION TECHNOLOGIES TECHNOLOGIES

Secondary Effluent Membrane Filtration

Hollow-Fiber (Zenon)Hollow-Fiber (Pall)

Two-Stage FiltrationFirst Stage: Secondary effluent filterSecond Stage: Hollow – Fiber Membrane

EVALUATED MEMBRANE FILTRATION EVALUATED MEMBRANE FILTRATION TECHNOLOGIES TECHNOLOGIES

Secondary Effluent Membrane Filtration

Hollow-Fiber (Zenon)Hollow-Fiber (Pall)

Two-Stage FiltrationFirst Stage: Secondary effluent filterSecond Stage: Hollow – Fiber Membrane

EVALUATED MEMBRANE BIOEVALUATED MEMBRANE BIO--REACTOR REACTOR TECHNOLOGIES TECHNOLOGIES

Flat Plate (Kubota/Enviroquip) Hollow Fiber (Zenon)

EVALUATION CRITERIA FOR TERTIARY EVALUATION CRITERIA FOR TERTIARY

TREATMENT TRAIN ALTERNATIVESTREATMENT TRAIN ALTERNATIVES

100.0%Total12.5%Site Requirements

7.5%Environmental Considerations/Safety

25.0%Operational and Maintenance Issues

30.0%Performance

25.0%Cost

WeightingFactor (a)

(a) Specific to Linda County Water District

ECONOMIC COMPARISON FOR TERTIARY ECONOMIC COMPARISON FOR TERTIARY TREATMENT TRAIN ALTERNATIVESTREATMENT TRAIN ALTERNATIVES

38,200,000

635,000

26,700,000

Two StageFiltration

37,600,00035,900,00024,000,000Net Present Value, $(b)

935,000615,000375,000Annual Operations and Maintenance Cost (a), $

21,560,00024,770,00016,870,000Capital Cost, $ (a) (Constructed Facility)

MBR

SecondaryEffluent

MembraneFiltrationConventional

(a) Includes costs only for secondary and tertiary processes.(b) Based on 20-year operating life cycle and average annual interest rate of 1.5 percent.

ECONOMIC EVALUATION MATRIX FOR ECONOMIC EVALUATION MATRIX FOR TERTIARY TREATMENT TRAIN TERTIARY TREATMENT TRAIN

ALTERNATIVESALTERNATIVES

5.0%10.0%10.0%

WeightingFactor

656565100Overall Weighted Score

3334Net PresentValue

2334Annual3224Capital

MBRTwo StageFiltration

SecondaryEffluent

MembraneFiltrationConventionalCost

PERFORMANCE EVALUATION MATRIX FOR PERFORMANCE EVALUATION MATRIX FOR

TERTIARY TREATMENT TRAIN ALTERNATIVESTERTIARY TREATMENT TRAIN ALTERNATIVES

2.5%2.5%2.5%2.5%2.5%2.5%2.5%2.5%

10.0%

WeightingFactor

11311511095Overall Weighted Score4443Regulatory Requirements3433Redundancy Requirement3433Reliability/Vendor Support4443Chemical Requirements4334Backwash Requirements4443Sludge Settleability4333Shock/Toxic Load Resistance3444Aeration Efficiency4443Effluent Quality

MBRTwo StageFiltration

SecondaryEffluent

MembraneFiltrationConventionalPerformance

OPERATIONAL AND MAINTENANCE OPERATIONAL AND MAINTENANCE EVALUATION MATRIX FOR TERTIARY EVALUATION MATRIX FOR TERTIARY TREATMENT TRAIN ALTERNATIVESTREATMENT TRAIN ALTERNATIVES

5.0%

5.0%

5.0%

5.0%

5.0%

WeightingFactor

70657595Overall Weighted Score

3234MaintenanceRequirements

3433Operational Flexibility

3234Operational History/Number of Installations

2234Operational Complexity

3334Operational SkillsRequirement

MBRTwo StageFiltration

SecondaryEffluent

MembraneFiltrationConventional

Operational andMaintenance Issues

ENVIRONMENTAL/SAFETY EVALUATIONENVIRONMENTAL/SAFETY EVALUATIONMATRIX FOR TERTIARY TREATMENT TRAIN MATRIX FOR TERTIARY TREATMENT TRAIN

ALTERNATIVESALTERNATIVES

2.5%2.5%2.5%

WeightingFactor

30303030Overall Weighted Score

4444Safety Issues4444Odor4444Noise

MBR

Two Stage

Filtration

SecondaryEffluent

MembraneFiltrationConventional

EnvironmentalConsiderations/ Safety

SITE REQUIREMENTS EVALUATION MATRIX SITE REQUIREMENTS EVALUATION MATRIX FOR TERTIARY TREATMENT TRAIN FOR TERTIARY TREATMENT TRAIN

ALTERNATIVESALTERNATIVES

2.5%

5.0%

5.0%

WeightingFactor

50404338Overall Weighted Score

4233Space Requirements

4433Expansion/Modification Requirements

4343Head Requirements

MBR

Two Stage

Filtration

SecondaryEffluent

MembraneFiltrationConventionalSite Requirements

ADJUSTED EVALUATION MATRIX FOR ADJUSTED EVALUATION MATRIX FOR TERTIARY TREATMENT TRAIN ALTERNATIVESTERTIARY TREATMENT TRAIN ALTERNATIVES

328315323358100.0%Total5040433812.5%Site Requirements303030307.5%

Environmental Considerations/Safety

7065759525.0%Operational and Maintenance Issues

1131151109530.0%Performance 65656510025.0%Cost

MBRTwo StageFiltration

SecondaryEffluent

MembraneFiltrationConventional

WeightingFactor

PROJECT STATUSPROJECT STATUS

Environmental study is in the final stage, and design is 50 percent complete

Design is scheduled to be completed by April 2007 and the construction is proposed to start in August 2007

WWTP DESIGN INFLUENT CHARACTERISTICSWWTP DESIGN INFLUENT CHARACTERISTICS

mg/l395Maximum dailymg/l275Maximum monthlymg/l190Average

Biochemical Oxygen DemandMGD13.8Peak Hourly FlowMGD9.9Maximum Day FlowMGD5.0Average Dry Weather FlowUnitsFlow rates

WWTP DESIGN INFLUENT CHARACTERISTICSWWTP DESIGN INFLUENT CHARACTERISTICS

º C22.9Minimum Monthly during Warm Weather º C14.3Minimum Monthly during Cold Weather

Wastewater Temperaturesmg/l55Maximum dailymg/l45Maximum monthlymg/l35Average

Ammoniamg/l575Maximum dailymg/l435Maximum monthlymg/l305Average unitsTotal Suspended Solids

LINDA COUNTY WATER DISTRICT LINDA COUNTY WATER DISTRICT WWTPWWTPEXISTING AND PROPOSED SITE PLANEXISTING AND PROPOSED SITE PLAN

EXISTING EXISTING TREATMENT TREATMENT

PLANTPLANT

NEW LIQUID NEW LIQUID PROCESSESPROCESSES

NEW SOLIDS HANDLING NEW SOLIDS HANDLING AND EMERGENCY AND EMERGENCY

OVERFLOW FACILITIESOVERFLOW FACILITIES

LINDA COUNTY WATER DISTRICT LINDA COUNTY WATER DISTRICT WWTPWWTPNEW LIQUID PROCESSES SITE PLANNEW LIQUID PROCESSES SITE PLAN

PRIMARY CLARIFIERSPRIMARY CLARIFIERS

ACTIVATED SLUDGE BASINSACTIVATED SLUDGE BASINS

CONTROL/BLOWER CONTROL/BLOWER BUILDINGBUILDING

HEADWORKSHEADWORKS

SECONDARY SECONDARY EFFLUENT EFFLUENT

FILTRATIONFILTRATION

SECONDARY SECONDARY CLARIFIERSCLARIFIERS

ACTIVATED SLUDGE BASINSACTIVATED SLUDGE BASINS

PrePre--Anoxic BasinsAnoxic BasinsBasin Side Water DepthBasin Side Water Depth 20 ft20 ftVolume per basinVolume per basin 0.23 MG0.23 MGActive Active denitrifierdenitrifier biomassbiomass 1,500 mg/l1,500 mg/lF/M (anoxic zone)F/M (anoxic zone) 0.8 d0.8 d--11

Specific Specific denitrificationdenitrification raterate 0.15 d0.15 d--11

Hydraulic detention timeHydraulic detention time 2 2 –– 3.5 hr3.5 hr

ACTIVATED SLUDGE BASINSACTIVATED SLUDGE BASINS

Aeration and Swing ZonesAeration and Swing ZonesBasin Side Water DepthBasin Side Water Depth 20 ft20 ftAeration zone volume per basinAeration zone volume per basin 0.8 MG0.8 MGSwing zone volume per basinSwing zone volume per basin 0.1 MG0.1 MGSolids retention timeSolids retention time 88--15 days15 daysMLSSMLSS 25002500--3500 3500 mg/lmg/lF/M (BOD)F/M (BOD) 0.11 d 0.11 d --11

F/M (Ammonia)F/M (Ammonia) 0.04 d 0.04 d --11BOD daily loading per 1,000 ftBOD daily loading per 1,000 ft33 1010--15 lb15 lb

ACTIVATED SLUDGE BASINSACTIVATED SLUDGE BASINS

MLSS Recirculation PumpsMLSS Recirculation PumpsNumber of pumps:Number of pumps: 1 per basin1 per basinRecirculation ratio:Recirculation ratio: 200 200 –– 450 percent450 percent

SECONDARY CLARIFIERSSECONDARY CLARIFIERS

Diameter 100 ftSide water depth 18 ftSurface Overflow Rate

ADF 360 gpd/ft²MDF 665 gpd/ft²

Solids Flux RateADF 0.7 lb/hr-ft²MDF 1.3 lb/hr-ft²

Return Activated Sludge (RAS)Return Ratio 75 – 150 %

SECONDARY EFFLUENT FILTRATIONSECONDARY EFFLUENT FILTRATION

Maximum Filtration Rate 30 gpm/ft²Filter Dimensions (L x W) 7 x 7 ftFilter Depth

Media Only 2.5 ftFilter Unit 13.9 ft

Compression Ratio Range 0 – 45 %

SECONDARY EFFLUENT FILTRATIONSECONDARY EFFLUENT FILTRATION

Filtration Rate (All in Service/ One out of Service)at ADF 13.0 / 15.6 gpm/ft²at MDF 22.9 / 27.5 gpm/ft²

Backwash Reject RatioAverage 3 %Peak 5 %

CONCLUSIONSCONCLUSIONS

Conventional tertiary treatment system with necessary design considerations for possible upgrade to two stage filtration system is recommended for Linda County Water District.

Near term more stringent requirements can be met both with conventional and advanced tertiary treatment systemsAdded benefits of advanced tertiary treatment systems with regards to near term effluent limitations was not evidentA very high level treatment (such as reverse osmosis) that requires membrane filtration as pretreatment may be required in the future for some contaminants of concernHigher capital and operational costs associated with the membrane involving alternatives is not justified for immediate and near term needs

CONCLUSIONSCONCLUSIONS

The recommended conventional tertiary system employs four plug-flow type activated sludge basins, two secondary clarifiers, and six compressible medium filters

Deferring membrane filtration provides the following benefits:Observe the outcomes from a dynamic regulatory environmentObtain performance data from the upgraded plantOverall potential capital cost savings: membrane technology cost may continue to decreaseMembrane technology is still advancing: more robust technology with less cleaning/backwash requirements in the future