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TMDL Number: 10-001

TOTAL MAXIMUM DAILY LOAD

Department of Ecology

P.O. Box 47600

Olympia, WA 98504~7600

Developed pursuant to 40 CFR 130.7 and the Federal Clean water Act

WATERRODY SEGMENT: WA-10-0020 RECEIVING SYSTEM INFORMATION:

Commencement Bay (Inner)

(S. and E.of line bearing 225 true

through Hylebos waterway Light to

the mouth of Puyallup River,

excludes City Waterway)

Basin:

County:

puyallup-White

Pierce

TMDL PARAMETER:

2,3,7,8 TCDD (Dioxin)

SOURCES COVERED BY THIS TMDL:

APPLICABLE RULES:

WAC 173-201-047(3)

WAC 173-201 047(4)

Allocation

Type

WLA

Source Description

Simpson at Tacoma

A TMDL for 2,3,7,8 TCDD of 0.07 mgper day to the Strait of Juan de Fuca. This

loading rate has been shown to be consistent with the narrative state water

quality criterion of 0.014 ppq at the edge of the mixing zone.

Technical Documents:

Industrial Section, Washington Department of Ecology. 1990 (version 2.0).

Proposed Effluent Limitations for Dioxin and AOX. Olympia, WA.

Publication # 92-10-201
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TMDL Number: 10-001

Implementation:

The WLA has been incorporated into the NPDES permit issued June 25, 1991 through

an interim control program.

Monitoring:

Ambient monitoring to assess TMDL implementation will be conducted by the

permittee before January 28, 1996 for bioaccumulation of TCDD in 4 species;

starry Flounder, Sandab, Mussels, and Crab.
United States

Environmental Protection

Agency

Reply to

Attn of: WD-139

MEMORANDUM

Region 10

1200 Sixth Avenue

Seattle WA 98101

APR 30 1992

Alaska

Idaho

Oregon

Washington

FROM:

SUBJECT:Recommendation for TMDL Approval

Commencement Bay (Inner) - dioxin

Amber Wong, Standards to Permits coordinatOJ;o;'t.L..,,- tJ(~ Water Quality section U

TO:

•

•

File

TMDL submitted March 9, 1992

TMDL package completed April 30, 1992

EPA Approval Checklist

Document 1: Transmittal letter

Document 2: TMDL document

Document 3: Industrial section, Washington

Department of Ecology. 1990 (version 2.0),

Proposed Effluent Limitations for Dioxin and AOX,

OlYmpia, WA

Document 4: Letter from Richard Burkhalter,

Ecology to Dave Ragsdale, EPA-WOO, transmitting

new TCDD and AOX effluent limits, dated January

29, 1991

Document 5: Public participation, pUblic notice

and pUblic hearing documentation

Document 6: NPDES Permit No. WA-000085-0

(Simpson-Tacoma Kraft Company), issued June 25,

1991, expiration date June 25, 1996

Document 7: Department of Ecology Order No. 91-

I059,to Simpson-Tacoma Kraft Company
Document 8: Fact Sheet for Simpson-Tacoma NPDES

permit, revised June 25, 1991

Document 9: Response to Comments received during

pUblic notice of simpson-Tacoma NPDES permit,

dated August 21, 1991

Transmittal letter - Complete (see Document 1)

• states that TMDL has been established in accordance

with section 303(d) (1) of the Clean Water Act.

• Review note: meets requirements

Problem Assessment - Complete (see Document 3)

Background

• Framework for TMDL came from EPA Dioxin Strategy

(1983), National Dioxin Study, five-mill study (1987),

U.S. EPA-Paper Industry Cooperative Dioxin Study (104

mill study, 1988).

• On October 20, 1988, EPA issued an interim strategy for

regulating dioxin discharges from existing mills. The

strategy set out proposed interim control measures for

chlorine minimization and suspended solids controls,

but stopped short of designating effluent limits.

• On June 9, 1989, Ecology listed 8 pUlp mills as

violating water quality standards for the priority

pollutant TCDD pursuant to section 304(1) of the Clean

Water Act. simpson-Tacoma, discharging to Inner

Commencement Bay, was one of these. An Individual

Control Strategy (ICS), defined as a water qualitybased permit, was required for Simpson-Tacoma.

Derivation of the TMDL for Commencement Bay for TCOD

was part of developing the permit.

Assessment

• The applicable water quality criterion for TCOD is

0.014 ppq, based on a 10 -6 risk level and ingestion of

aquatic organisms only (no drinking water component).

• Data from Simpson-Tacoma showed measurable quantities

of dioxin in effluent and sludge. These values showed

that existing effluent would cause violations of the

dioxin water quality standard.

• only one point source (simpson) was identified, which

had no existing controls for TCDO.

2
• Review notes: Problem assessment accurately gives

background information, identifies exceedence of water

quality standard for dioxin due to one point source in

the waterbody. supporting information - effluent,

sludge, fish data - quantify simpson's contribution.

TMDL document - Complete (see Document 2)

• states that a load of 0.07 mg/day has been established

for the point source.

• Review note: Clearly identifies the load capacity for

the TMDL. clearly links this to the water quality

criterion. concisely summarizes the implementation and

monitoring followup (through the NPDES permit).

Clearly references the supporting technical documents.

Supporting Studies - Complete (see Documents 3 and 4)

• TCDD limit (WLA) was calculated based on compliance

with the water quality criteria at the edge of the

dilution zone. Three factors in calculating the WLA

were: 1) applicable water quality criterion of 0.014

ppq, 2) dilution of 90:1, and 3) background

concentration in Commencement Bay of 0.007 ppq (50% of

the water quality criterion for TCDD). TCDD limit =

0.63 ppq.

• Mill final effluent flow averages 28.8 mgd. Combined

bleach plant effluent flow is estimated at 2.5 mgd.

Combined bleach plant effluent TCDD concentration is

7.3 ppq.

• For compliance purposes, annual average load for this

mill = 0.07 mg/day. Daily maximum limit is 0.13

mg/day. For compliance with the daily maximum limit,

the final effluent concentration is 1.2 ppq.

• Simpson must meet this level by March 8, 1994.

• Permit issued June 25, 1991.

• Review notes: Documentation clearly gives basis for

calculating the TMDL. Although dilution calculation is

relatively simple, it is valid in the absence of more

sophisticated analysis. Consideration of a margin of

safety (50%) is good. Calculation of the WLA - fine.

Clarification of the number to be used for compliance

purposes is good. The date for meeting the effluent

limits falls within guidelines.

Public participation - Complete (see Document 5)

3
• Public notice of the permit and load allocation from

September 7, 1990 to October 23, 1990. Public hearing

on the permit on October 16, 1990.

• Review notes: Adequate pUblic participation.

Enforceability - Complete (see Documents 6,7,8 and 9)

• NPDES Permit No. WA-000085-0, Simpson-Tacoma

• Review notes: Valid permit with applicable conditions

TMDL effectiveness plan - Complete (see Document 6,7, and 8)

• In permit: ambient monitoring - sediment (in vicinity

of outfall), bioaccumulation.

• related monitoring - Superfund action on the St. Paul

Waterway, monitoring of the cap placed on contaminated

sediments. Monitoring plan spelled out in separate

document.

• Review notes: Adequate monitoring to assess compliance

with the TMDL.

Recommendation, approve TMDL.

ALW, 4/30/92

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