Raj Kapur

Clean Water Services

OutlineMajor municipal facilities

2006 Willamette Mercury TMDL

Clean Water Services Permit

Mercury Minimization Plan

Monitoring Results

Summary

Municipal Treatment Facilities Sources of wastewater

50 major facilities in Oregon

Size of major facilities:

Sweet Home, Cottage Grove (pop. <10,000)

Portland, Clean Water Services (pop.>500,000)

Type of wastewater facilities

Designed to remove oxygen-demanding pollutants, solids and bacteria

Also very effective at removing metals, mercury and other pollutants

City of Albany Willamette River (RM 118.0) 8.7

City of Canby Willamette River (RM 33) 2.0

City of Corvallis Willamette River (RM 130.8) 9.7

City of Cottage Grove CF Willamette River (RM 21.5) 1.8

City of Dallas Rickreall Creek 2.0

MWMC - Eugene/Springfield Willamette River (RM 178.0) 49.0

City of Lebanon South Santiam (RM 17.4) 3.0

City of McMinnville S. Yamhill River (RM 1.0) 5.6

City of Newberg Willamette River (RM 49.7) 4.0

City of Portland-Tyron Creek Willamette River (RM 20.3) 8.3

City of Salem Willamette River (RM 78.1) 35.0

City of Silverton Silver Creek (RM 2.4) 2.5

City of Stayton North Santiam (RM 14.9) 1.9

City of Sweet Home South Santiam (RM 31.5) 1.4

City of Wilsonville Willamette River (RM 38.6) 2.7

City of Woodburn Pudding River (RM 21.4) 5.0

Clackamas WES - Tri-Cities Willamette River (RM 25.5) 11.9

Clackamas WES - Kellogg Creek Willamette River (RM 18.7) 10.0

Clean Water Services-Durham Tualatin River (RM 9.2) 25.7

Clean Water Services-Rock Creek Tualatin River (RM 37.7) 46.4

Clean Water Services-Forest Grove Tualatin River (RM 53.8) 6.3

Clean Water Services-Hillsboro Tualatin River (RM 43) 4.5

Oak Lodge Sanitary District Willamette River (RM 20.1) 4.0

Receiving streamMunicipal Treatment Facility

Average Dry

Weather Design

Flow (MGD)

2006 Willamette Basin Mercury TMDL TMDL findings

for mainstem Willamette River:

More than 95% of mercury from soil erosion and air deposition – local and global

Small quantity from municipal WWTFs

Abandoned mines

2006 Willamette Basin Mercury TMDL 26.4% reduction in total mercury is needed

Sector specific allocations

Point sources:

Implement mercury minimization efforts

Conduct mercury monitoring

Assess BMP approach over time as part of an adaptive management strategy; DEQ would also update the TMDL

TMDL provisions not fully implemented

Clean Water Services Permit 4 treatment facilities & municipal storm water

system in urban Washington County

Watershed-based NPDES permit

Permit includes:

Monitoring

Quarterly monitoring of influent and effluent

Parameters: mercury, dissolved mercury, methyl mercury, dissolved methyl mercury

Mercury Minimization Plan

Submitted as part of permit renewal

Incorporated into final permit

Mercury Sources in Wastewater

Mercury Minimization Plan Key Elements:

Survey/inspect dental offices

Audit of CWS facilities

Industry monitoring

Outreach to schools/healthcare facilities/laboratories

Commercial/residential outreach

Implementation Status

Monitoring WWTF influent, effluent and biosolids monitoring

Influent/effluent levels of total mercury

% removal

Estimated loading

Recent data (methyl mercury)

Biosolids

Ambient data

Total Mercury

Effluent Mercury StatisticsStatistic

Rock Creek WWTF

Durham WWTF

Forest Grove WWTF

Hillsboro WWTF

Number of Samples 174 176 104 119

Geometric Mean (ng/L) 1.6 1.6 2.2 2.9

Maximum (ng/L) 5.1 5.8 14.2 18

Standard Deviation 0.93 0.83 2.0 1.7

Coefficient of Variation 0.51 0.46 0.74 0.54

Annual Average Flow (MGD) 57.4 33.9 7.1 3.9

Mass Load (kg/year) 0.13 0.08 0.02 0.01

2006 Willamette TMDL Mass Load Estimate (kg/yr)

0.69 0.51 0.06 0.10

Methyl Mercury

Biosolids

Ambient Data

UpstreamDownstream

Technology Evaluation Literature review to evaluate performance of treatment

strategies

Technologies evaluated: precipitation, filtration, ion exchange, reverse osmosis

Technologies used for industrial applications with much higher loading & effluent concentrations

Did not identify pilot or full-scale systems that would be able to achieve potential mercury limits

Summary Receive wastewater from residential/commercial/

industrial sources and treat it before release

Designed to remove conventional pollutants (solids, BOD, bacteria)

Also very effective at removing mercury (>95%)

Significant reduction in methyl mercury

Produce high quality effluent that exceeds federal standards

Mercury monitoring is very expensive; need to ensure that data being collected informs management actions

Summary (cont.) Mercury loading from municipal treatment facilities

Well below 2006 TMDL estimate

Primary source of mercury: dental facilities; actions taken to reduce mercury

Remaining mercury sources are diffuse

Municipal actions geared toward reducing mercury in the environment; doesn’t have a wastewater nexus

Technology solutions not available to reduce effluent concentrations to target levels

Mercury minimization plan is the most effective approach

What does this mean?? Municipal facilities will likely consider a variance

Clean Water Act tool when water quality based effluent limits cannot be met

Waiver would likely be based on these factors:

Naturally occurring pollutant concentrations prevent attainment of the criterion.

Human-caused conditions or pollutions sources prevent attainment of the criterion and cannot be remedied.

Controls more stringent than technology-based controls will result in substantial and widespread economic and social impact.

Minimization plan would be an element of a variance

Questions?

Contact information:Raj Kapur

Clean Water Services

Kapurr@cleanwaterservices.org

503-681-4424