# Presentation: 143337

## Overview of the draft Pend Oreille RiverTotal Dissolved Gas Total Maximum Daily Load

**Paul J. Pickett, P.E.**
**Transboundary Gas Group**
**Castlegar, BC**
**October 19, 2006**

## Overview of the Draft Pend Oreille River TDG TMDL 

**Why a TMDL on the Pend Oreille River?**
- Total dissolved gas data exceed WA state water quality criteria
- Federal legal requirement: Determine the “total maximum daily load” (TMDL) of pollutants
- TMDL = technical analysis + implementation plan
- Ecology conducted technical studies in 2004 to augment other data and studies

## Overview of the Draft Pend Oreille River TDG TMDL 

- Geographic scope and jurisdictions
- Ecology is addressing Washington state waters
- Idaho border to Canada border
- Environmental Assessment Program (Olympia): technical
- Water Quality Program/Eastern Region (Spokane): public outreach & implementation
- EPA lead for Kalispel Tribal waters
- EPA also coordinating interstate and international issues

## Overview of the Draft Pend Oreille River TDG TMDL 

- Dams on the Pend Oreille River
- Boundary Dam – Seattle City Light
- Box Canyon Dam – Pend Oreille PUD
- Albeni Falls Dam – Seattle Army Corps
- Others upstream on the Clark Fork
- TDG listings in Idaho and Montana
- Cabinet Gorge FERC 401 certification
- Other sources in Montana

## Pend Oreille/Clark Fork Watershed (U.S.A. area)

**Cabinet Gorge**

## Slide 6

## Albeni Falls Dam

## Box Canyon Dam

## Boundary Dam

## Boundary Dam in the Future (“The Postman”)

## Overview of the DraftPend Oreille River TDG TMDL 

- TDG technical study
- TDG monitoring by dam owners
- Albeni Falls, Box Canyon, Boundary
- Forebay and Tailrace
- Ecology continuous monitoring
- Near Ruby – local resident’s dock
- Ecology paired monitoring
- About every two weeks – “snapshot”
- Newport, dam forebays, Ecology site
- Project Plan is available
- _http://www.ecy.wa.gov/biblio/0403107.html_

## Overview of the Draft Pend Oreille River TDG TMDL 

- Pend Oreille River Flows
- TDG elevated during peak freshet flows
- Mid-April through mid-July
- Study period flows varied widely
- 2001 critical low flow year
- 2002 high flow year
- 2003 average flow year
- 2004 low flow year
- 7Q10 flood flows = 105,500 – 108,300 cfs
- WA standards: criteria only apply below 7Q10 flood

## Overview of the Draft Pend Oreille River TDG TMDL 

**2001**

**2002**

**2003**

**2004**

## Overview of the Draft Pend Oreille River TDG TMDL 

- Box Canyon Reservoir
- TDG often elevated at Idaho State Line
- Fate in reservoir evaluated
- Difference of paired values (Box FB – ID SL)
- Separate temperature effect from wind and productivity
- Ecology data from Ruby: separate southern and northern half of reservoir
- Analyze periods of impairment

## Overview of the Draft Pend Oreille River TDG TMDL 

## Overview of the Draft Pend Oreille River TDG TMDL 

***Overview of the Draft ******Pend Oreille River TDG TMDL ***

## Overview of the Draft Pend Oreille River TDG TMDL 

## Overview of the Draft Pend Oreille River TDG TMDL 

## Overview of the Draft Pend Oreille River TDG TMDL 

## Overview of the Draft Pend Oreille River TDG TMDL 

- Box Canyon Reservoir Analysis of Impairments
- Most impairments caused by conditions upstream of Washington
- Effect of Temperature usually offset by wind or productivity
- Increase in TDG producing impairment is rare
- Amount of increase is small

## Overview of the Draft Pend Oreille River TDG TMDL 

- Box Canyon Dam TDG Generation
- Rising flows force spill
- Rising river levels decrease powerhouse efficiency
- Powerhouse shuts down at high flows (around 85 kcfs)
- As river rises, TDG generation peaks, then drops
- Rising tailrace river levels reduce height of spill
- Currently, spills above about 5 kcfs impair TDG

## Overview of the Draft Pend Oreille River TDG TMDL 

***Overview of the Draft ******Pend Oreille River TDG TMDL ***

## Overview of the Draft Pend Oreille River TDG TMDL 

- Boundary Reservoir
- TDG often elevated from Box Canyon and Idaho
- Fate in reservoir evaluated

## Overview of the Draft Pend Oreille River TDG TMDL 

## Overview of the Draft Pend Oreille River TDG TMDL 

## Overview of the Draft Pend Oreille River TDG TMDL 

***Overview of the Draft ******Pend Oreille River TDG TMDL****** ***

## Overview of the Draft Pend Oreille River TDG TMDL 

- Boundary Reservoir Analysis of Impairments
- Most impairments caused by Box Canyon Dam and upstream conditions
- Effect of Temperature usually offset by wind or productivity
- Increase in TDG producing impairment is rare
- Amount of increase is small

## Overview of the Draft Pend Oreille River TDG TMDL 

- Boundary Dam TDG Generation by _spill_
- High upstream TDG levels “mask” effect of spill
- Spill above 14 kcfs causes increase of tailrace TDG above forebay levels
- Spill TDG generation can be estimated by back-calculation (with a few simplifying assumptions)
- Tailrace TDG if forebay were in compliance can be estimated
- If forebay were in compliance, spills above 4 kcfs would impair TDG

## Overview of the Draft Pend Oreille River TDG TMDL 

***Overview of the Draft ******Pend Oreille River TDG TMDL ***

## Overview of the Draft Pend Oreille River TDG TMDL 

- Boundary Dam TDG Generation by _powerhouse_
- TDG above 110% in tailrace sometimes occurs when there is no spill and no forebay impairment
- Usually occurs at very low flows
- Powerhouse shutdown and start up
- Related to air intake by turbines to prevent blade damage

## Overview of the Draft Pend Oreille River TDG TMDL 

## Overview of the Draft Pend Oreille River TDG TMDL 

## Overview of the Draft Pend Oreille River TDG TMDL 

## Overview of the Draft Pend Oreille River TDG TMDL 

- Loading capacity and allocations
- Equivalent to 110% saturation at low barometric pressure
- Compliance areas
- Entire Pend Oreille River in Washington, _except..._
- Aerated (“bubbly”) zones below dams excluded
- Compliance area begins at tailrace location specified in Implementation Plan
- Draft location: existing tailrace monitoring sites.
- Compliance flows
- Idaho State Line to Kalispel Reservation: all flows
- Kalispel Res. to Int’l Border: only below 7Q10 flood flow

## Overview of the Draft Pend Oreille River TDG TMDL 

- TMDL review and submittal
- TMDL = technical analysis (what you just saw)
- 				+ implementation plan

## Overview of the Draft Pend Oreille River TDG TMDL 

- Implementation Plan
- Box Canyon Dam 401 Certification
- 	(effective July 2005)
- TDG Abatement Plan
- Water Quality Monitoring Plan
- Boundary Dam FERC relicensing (due 2011)
- Pre-application Document (May 2006)
- Proposed Study Plan (October 2006)
- Upstream Sources
- Jurisdiction of Idaho and Montana
- U.S. EPA oversight

## Overview of the Draft Pend Oreille River TDG TMDL 

- Boundary Dam “Super Six”
- Throttle Sluice Gates
- Roughen Sluice Gate Discharge
- New Right Abutment Tunnel with Submerged Discharge
- New Left Abutment Tunnel Intercepts Diversion Tunnel
- Penstock/Draft Tube By-Pass
- New Short Left Abutment Tunnel Next to Unit #51
- Stay tuned!
- (Seattle City Light will provide details as planning continues)

## Overview of the Draft Pend Oreille River TDG TMDL 

- TMDL review and submittal
- TMDL = technical analysis
- 				+ implementation plan
- Continue coordination with stakeholders
- Formal review and public comment of final draft TMDL
- WA issues for state waters and submits to EPA
- EPA adopts for tribal waters and approves WA
- Implementation

## Overview of the Draft Pend Oreille River TDG TMDL 

- Questions?
- Contact info:
- Paul Pickett, EAP Olympia
- 	(360) 407-6882
- 	_ppic461@ecy.wa.gov_
- Jon Jones, WQP Spokane
- 	(509) 329-3481
- 	_jojo461@ecy.wa.gov_