Water Quality Trading in Oregon

Clean Water Services: A Case Study

Sonja Biorn-Hansen, Sr. Policy Analyst, Water Quality Permitting Program

How It Started…

Back in 2002, EPA awarded DEQ a grant to:

• Identify, develop and implement a model trade

• Develop policy and guidance regarding trading

• Promulgate the lessons learned

DEQ considered a variety of potential trades before deciding to work with Clean Water Services.

The trade was designed with stakeholder input.

Clean Water Services: Overview

• Located in the Tualatin Basin

• Serve over 500,000 customers

• Durham (22 mgd) and Rock Creek (39 mgd) plants both discharge during the summer

• 2001 TMDL req’d a 90% reduction in heat load from CWS, and allowed for trading

• In 2005, DEQ issued a permit that allowed trading for temperature as well as oxygen-demanding substances

CWS CBOD/Ammonia Trade

• Permit allows trading of oxygen-demanding substances between the Durham and Rock Creek treatment plants

• Permit contains equations that define allowable loading rates that insure impact on dissolved oxygen is never greater than 0.1 mg/L

• CWS is able to meet effluent limits for CBOD and ammonia without trading

Tualatin River

Gales C

reek

McK

ay C

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Ro

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Sco

ggin

s Cre

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reek

Wes

t F

ork

Da

i ry

Cre

ek

Fanno

Cre

ek

Da

i ry C

reek

B ronson Creek

Sain CreekM

cFee

Cre

e k

Beaverton Creek

Iler Creek

Be

ave

r C

r ee

k

Roaring Creek

Denny Creek

Ch icken C

reek

Burgholzer Creek

Ash

Cre

ek

Clear CreekAbbey C reek

Joh

ns

on

Cre

ek

Menden

hall C

reek

Wh

itch

er

Cre

ek

Sa

dd C

reek

Pai

s ley C

anyon

Will

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ree

k

So

ut h

Fo

rk G

ale

s Cr ee

k Jackson Creek

Da

ws

on

Cre

ek

Summer Creek

Bateman Creek

Ced

ar Cr eek

Butternut Creek

Cedar Canyon

Warble Gulch

Ro

deri

ck C

ree

k

Whisky Creek

Ro

c k Cre

ek

Hillsboro

Tigard

BeavertonPortland

Tualatin

Forest Grove

Sherwood

Cornelius

West Linn

Lake Oswego

Banks

North Plains

River Grove

King City

Gaston

Tualatin Basin Boundary

Land UseDeveloped LandAgricultureForestlandWaterWetlandsBarren Land

CitiesOther StreamsSalmonid Migration Streams Salmonid Spawning StreamsTualatin Mainstem

Tualatin Basin: Salmonid Streams and Land Uses

TMDL report: Tualatin River Temperature Profile (Observed and Predicted for 7/27/99)

Left Bank

Right Bank

Forest Land Agriculture Lands Urban Lands Transportation

Land Use Gaston West Linn

Le

e

Fa

lls

Sco

gg

ins C

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Gale

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Durh

am

WW

TP

Fa

nno

Cr.

Some Reaches areStratified Between RiverMile 0 and River Mile 27

50

55

60

65

70

75

80

05101520253035404550556065707580

River Mile

Str

eam

Tem

pe

ratu

re (oF

)

Simulated Stream Temperature

FLIR Derived Stream Temperatures

FLIR Break4:00 PM5:00 PM

Conclusion

The major cause of temperature problems in the Tualatin is not Clean Water Services.

“Good” Riparian Area

“Bad” Riparian Area

Back to CWS…

Options considered for complying:

• Reuse (insufficient opportunity)

• Send the effluent to another river (Expensive - too far and the other rivers are also Water Quality Limited)

• Evaporative cooling (insufficient)

• Refrigeration (lots of electricity)

• Outlaw hot water heaters?

• Trading…??

The “Winner”: Trading

The temperature trade includes:

– Riparian shading

– Flow augmentation The design of the trade was strongly influenced by stakeholder input.

Flow Augmentation

• Achieved by release of cool water from Hagg Lake Reservoir

• Augmented flow cools river both directly and indirectly (increased flow rate means less time for heating from sun)

• Thermal credits quantified using TMDL model

• Flow Augmentation unique to CWS, discussion focuses on Shading Program

Focus: Riparian Restoration

The major issues:

• How much to plant?

• Where to plant?

• What to plant?

• How to get it planted?

• How to keep it planted?

How much to plant?

• Quantified by calculating the amount of solar radiation blocked by shade-producing vegetation.

• Expressed as kcal/day that must be blocked by shade.

• Took into account difference between immature trees and refrigeration equipment.

• Planning horizon was 20 years.

So how much stream restoration is enough?

The Basic Equation:

Length of Stream Required =

Excess Heat Load (per day)

(Reduced Solar Load x Stream Width)

Daily Solar Loading Rates

Right Bank

Forest Land Agriculture Lands

Land Use

Urban Lands Transportation

Left Bank

Forest Grove

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0123456789

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

River Mile

Su

rro

ga

te M

ea

su

re (

Eff

ec

tiv

e S

ha

de

)

0

64

127

191

255

318

382

446

509

573

637

So

lar

Ra

dia

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n F

lux

(ly

/da

y)

Current Condition

System Potential Condition

1/2 Mile Moving Average (Current Condition)

1/2 Mile Moving Average (System Potential Condition)

Effective Shade on Gales Creek

Problems…

• Doesn’t trading amount to giving CWS credit for something the farmers should already be doing?

• Trees take a long time to grow…

Response

When CWS trade was developed, farmers were not required by ODA to actively plant riparian areas, instead they were required to allow for the establishment of riparian vegetation.

Compensating for the Time to Grow Trees

0

1

2

1 3 5 7 9 11 13 15 17 19 21

Cooling via Refrigeration

Cooling via Shade from Trees

Time (years)

Co

olin

g

The equation modified…

Length of Stream Required

= ______2 x Excess Heat Load______

(Reduced Solar Load x River Width)

Where to plant?

Factors to consider:

• Ability of stream to support salmonids (particularly spawning, rearing)

• Current riparian condition/stream temp.

• Willingness of landowners to participate

What to plant?

The short answer: natives.

The CWS plant list included:

•16 tree species

•27 shrub species

•6 different types of grass

How to get (and keep) it planted?

• CWS put together a program to pay farmers to have riparian areas planted (“Enhanced CREP” )

• CWS had a contract with NRCS to enroll farmers

• There are 1900 farmers in the basin.

Incorporating Trading into Permits

Overview of the CWS permit:

• Schedule A defines allowable thermal load

• Schedule D authorizes trading

• Schedule C describes contents of Temperature Management Plan (TMP), due 90 days from permit issuance

• TMP is CWS’ plan for reducing/offsetting

their excess thermal load.

Establishing Compliance

Compliance based on:

• First 5 years: adherence to planting plans

• After 5 years: plant survival rates and shade density measurements

If CWS complies with TMP, CWS is in compliance with the permit.

RESULTS (as of 2013)

• 35 cfs of flow augmentation from Hagg Lake

• 84 projects resulting in over 40 miles of stream planted, ½ urban, ½ rural.

• A total of 37 rural landowners involved.

• Average shade density after 5 years: 69%

• Total cost: about $5 million

• Savings: over $50 million in capital costs plus over $2 million a year in operating costs

CWS Restoration Example

Fanno Creek (Englewood: 1.3 mile restoration for 16.5 million kilocalorie

temperature credits)

May 2006 Oct 2006 May 2011 Pre-restoration @ Planting Post-restoration

Englewood Park - 2006

Englewood Park - 2007

Englewood Park - 2012

What we heard from the stakeholders…

• Pursue trades involving shade • Allow shade projects on tributaries • Compensate for the time it takes trees to

grow • Some uncertainty acceptable if overall

environmental gain w. trading is clearly greater than technology-based solution.

Conclusions

• Trading can be used to accelerate the rate of restoration in the watershed.

• With trading available as a tool, we can ask “What is the best way to protect the resource?”