### Fact Sheet for NPDES Permit No. WA 0023451

Lakehaven Utility District

Redondo Wastewater Treatment Plant

August 27 , 2013

Purpose of this f act s heet

This fact sheet explains and documents the decisions the Department of Ecology (Ecology) made in drafting th e proposed National Pollutant Discharge Elimination System (NPDES) permit for Lakehaven Utility District ’s Redondo Wastewater Treatment Plant (WWTP)

. This fact sheet complies with Section 173

- 220

- 060 of the Washington Administrative Code (WAC), which requ ires Ecology to prepare a draft permit and accompanying fact sheet for public evaluation before issuing an NPDES permit.

Ecology makes the draft permit and fact sheet available for public review and comment at least thirty (30) days before issuing the fi nal permit. Copies of the fact sheet and draft permit for

Redondo WWTP , NPDES permit No. WA 0023451 , were available for public review and

comment from July 22, 2013 until August 21, 2013

. For more details on preparing and filing

comments about the se documents , please see Appendix A

- Public Involvement Information

. Lakehaven Utility District reviewed the draft permit and fact sheet for factual accuracy. Ecology corrected any errors or omissions regarding the facility’s location, history, wastewater
d ischarges

, or receiving water prior to publishing this draft fact sheet for public notice

. After the public comment period close d , Ecology summarize s substantive comments and provide s responses to them. Ecology include s the summary and responses to comm ents in this

fact sheet as Appendix E

- Response to Comments , and publish es it when issuing the final NPDES permit. Ecology did not revise the rest of the fact sheet, but the full document become s part of the legal history contained in the facility’s permit file.

Summary

The Lakehaven Utility District (the District) operates a 5.6 MGD trickling filter wastewater treatment plant that discharges to Poverty Bay in mid

- Puget Sound. Ecology issued the previous permit for this facility on July 31, 2008 and modified it on November 1, 2008. The proposed permit contains the same effluent limits for Carbonaceous Biochemical Oxygen Demand (CBOD 5 ), Total Suspended Solids (TSS), Fecal Coliform Bacteria, pH, an d chlorin e as the permit amended on November 1, 2008

.Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 2 of 73



## Table of Contents

I. Introduction

................................ ................................ ................................ ............ 5

II. Background Information

................................ ................................ ....................... 6

A. Facility description

................................ ................................ ................................ 7 History

................................ ................................ ................................ ................................ 7 Collection system status

................................ ................................ ................................ ...... 7 Treatment processes

................................ ................................ ................................ ............ 8

Staff

................................ ................................ ................................ ................................ ..... 8

Solid wastes/Residual Solids

................................ ................................ .............................. 8 Discharge outfall

................................ ................................ ................................ ................. 8

B. Description of the receiving water

................................ ................................ ....... 9

C. Wastewater influent characterization

................................ ................................ . 9

D. Wastewater effluent characterization

................................ ................................ . 9

E. Summary of compliance with previous permit issued July 31, 2008

............. 10

F. State environmental policy ac t (SEPA) compliance

................................ ........ 11

III. Proposed Permit Limits

................................ ................................ ........................ 11

A. D esign criteria

................................ ................................ ................................ ..... 11

B. Technology

- based effluent limits

................................ ................................ ....... 12

C. Surface water quality

- based effluent limits

................................ ...................... 13 Numerical criteria for the protection of aquatic life and recreation

................................ .. 13 Numerical criteria for the protection of human health

................................ ...................... 14

Narrative criteria

................................ ................................ ................................ ............... 14 Antidegradation

................................ ................................ ................................ ................ 14 Mixing zones

................................ ................................ ................................ ..................... 15

D. Designated uses and surface water quality criteria

................................ ......... 19

E. Water quality impairments

................................ ................................ ................ 20

F. E valuation of surface water quality

- based effluent limits for numeric criteria

................................ ................................ ................................ ............................... 20 Reasonable Potential Analysis

................................ ................................ .......................... 24

G. Human health

................................ ................................ ................................ ...... 24

H. Sediment quality

................................ ................................ ................................ .. 25

I. Whole eff

luent toxicity

................................ ................................ ........................ 25

J. Groundwater quality limits

................................ ................................ ................ 26

K. Comparison of effluent limits with the previous permit modified on

November 1, 2008

................................ ................................ ................................ 26

IV. Monitoring Requirements

................................ ................................ .................... 27

A. Wastewater monitoring

................................ ................................ ...................... 27Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 3 of 73

B. Lab accreditation

................................ ................................ ................................ 28

V. Other Permit Conditions

................................ ................................ ...................... 28

A. Rep orting and record keeping

................................ ................................ ........... 28

B. Prevention of facility overloading

................................ ................................ ...... 29

C. Operation and maintenance

................................ ................................ ............... 29

D. P retreatment

................................ ................................ ................................ ........ 30 Duty to enforce discharge prohibitions

................................ ................................ ............. 30 Federal and state pretreatment program requirements

................................ ...................... 30 Routine identification and reporting of industrial users

................................ .................... 31

E. Solid wastes

................................ ................................ ................................ .......... 31

F. General conditions

................................ ................................ .............................. 31

VI. Permit Issuance Procedures

................................ ................................ ................ 31

A. Permit modifications

................................ ................................ ........................... 31

B. Proposed permit issuance

................................ ................................ ................... 32

VII. References for Text and Appendices

................................ ................................ ... 32

Appendix A

-- Public Involvement Information

................................ ................................ ......... 33

Appendix B

-- Your Right to Appeal

................................ ................................ ........................... 34

Appendix C

-- Glossary

................................ ................................ ................................ ................ 35

Appendix D

-- Technical Calculations

................................ ................................ ........................ 43

Appendix E

-- Response to Comments

................................ ................................ ........................ 70

Table 1. General Facility Information

................................ ................................ ........................... 6

Table 2. Ambient Background Data

................................ ................................ .............................. 9

Table 3. Wastewater Influent Characterization

................................ ................................ ............. 9

Table 4. Wastewater Effluent Characterization

................................ ................................ ............. 9

Table 5. Violations/Permit Triggers

................................ ................................ ............................ 10

Table 6. Permit Submittals

................................ ................................ ................................ ........... 10

Tabl e 7. Design Criteria for Redondo WWTP

................................ ................................ ............. 12

Table 8. Technology

- based Limits

................................ ................................ .............................. 12

Table 9. Technology

- based Mass Limits

................................ ................................ ..................... 13

Table 10. Critical Conditions Used to Model the Discharge

................................ ....................... 17

Table 11. Marine Aquatic Life Uses and Associated Criteria

................................ ..................... 20

Table 12. Recreational Uses

................................ ................................ ................................ ........ 20Fact Sheet for NPDES Permit No.WA 0023451

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Table 13. Dilution Factors (DF)

................................ ................................ ................................ ... 21

Table 14. Comparison of Previous and Proposed Effluent Limits

................................ .............. 27

Table 15. Accredited Parameters

................................ ................................ ................................ . 28

Figure 1. Facility Location Map

................................ ................................ ................................ .... 7

Figure 2. Dilution Necessary to Meet C riteria at Edge of Mixing Zone

................................ ...... 24Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 5 of 73



### I. Introduction

The F ederal Clean Water Act (FCWA, 1972, and later amendments in 1977, 1981, and 1987) established water quality goals for the navigable (surface) waters of the United State s. One mechanism for achieving the goals of the Clean Water Act is the National Pollutant Discharge Elimination System (NPDE S ), administered by the federal Environmental Protection Agency (EPA). The EPA authorized the s tate of Washington to manage the NP DES permit program in our state. Our state legislature accepted the delegation and assigned the power and duty for conducting NPDES permitting and enforcement to Ecology. The L egislature defined Ecology's authority and obligations for the wastewater disc harge permit program in 90.48 RCW (Revised Code of Washington).

The following regulations apply to domestic wastewater NPDES permits:

 Procedures Ecology follows for issuing NPDES permits ( c hapter 173

- 220 WAC)

.

 Technical criteria for discharges from munic ipal wastewater treatment facilities (c hapter

173

- 221 WAC)

.

 Water quality criteria for surface waters ( c hapter 173

- 201A WAC)

.

 Water quality criteria for groundwater s ( c hapter 173

- 200 WAC)

.

 Whole effluent toxicity testing and limits (chapter 173

- 205 WAC)

.

 Sediment management standards ( c hapter 173

- 204 WAC)

.

 Submission of plans and reports for construction of wastewater facilities ( chapter 173

- 240 WAC)

. These rules require any treatment facility owner/operator to obtain an NPDES permit before discharging was tewater to state waters. They also help define the basis for limits on each discharge and for requirements imposed by the permit.

Under the NPDES permit program and in response to a complete and accepted permit application

, Ecology must prepare a draft permit and accompanying fact sheet, and make them

available for public review before final issuance . Ecology must also publish an announcement (public notice) telling people where they can read the draft permit, and where to send their comments, during a period of thirty days (WAC 173

- 220

- 050). ( See Appendix A

- Public

Involvement Information for more detail about the public notice and c omment procedures). Aft er the public comment p eriod ends , Ecology may make changes to the draft NPDES permit in response to comment(s)

. Ecology will summarize the responses to comments and any changes to the permit in Appendix E

.Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 6 of 73



### II. Background Information

Table 1

. General Facility Information

Facility Information

Applicant Lakeh aven Utility District
31627 First Avenue South Federal Way, WA 98023

Facility Name and Address Redondo WWTP
515 S. 288 th Street Des Moines, WA 98198

Contact at Facility Name: Mr. Chris McCalib

Title: WWTP Operations Manager Telephone #: 253

- 945

- 1621

Responsible Official Name: Mr. John Bowman

Title: General Manager

Lakeh aven Utility District

Address: PO Box 4249

Federal Way, WA 98063 Telephone #: 253

- 94 6

- 5401

FAX # : 253

- 839

- 9310

Type of Treatment Trickling Filter (Secondary Treatment)

Facility Location (NAD83/WGS84 reference datum) Latitude: 47.34346 Longitude:

- 122.3279

Discha rge Waterbody Name and Location (NAD83/WGS84 reference datum) Puget Sound

– Poverty Bay
Outfall Location No.001:

Latitude: 47.34 941 Longitude:

- 122.33 8038

Permit Status

Issuance Date of Previous Permit 7/31/08

Modification Date of Previous Permit 11/1/08

Application for Permit Renewal Submittal Date 1/ 8 /13

Date of Ecology Acceptance of Application 2/8/13

Inspection Status

Date of Last Sampling Inspec tion 5 / 1 2/0 9

Date of Last Non

- sampling Inspection Date 7 / 23 / 13Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 7 of 73

Figure 1

. Facility Location Map

A. Fa cility d escription

History

Lakehaven Utility District, formerly known as Federal Way Water and Sewer District, owns and operates two wastewater treatment plants, Lakota WWTP and Redondo WWTP , which discharge to the Puget Sound. The Redondo WWTP is the smaller of the two with a maxim um month average design flow of 5.6 million gallons per day (mgd). The District built the original plant in 1962 for primary treatment and upgraded the plant with secondary treatment in 1983. The District

installed new odor control facilities and a solid s handling facility with a belt filter press in 1988 and a UV disinfection process in 2000. The belt filter press was removed and replaced with a

rotary pres s in 2010.

C ollection s ystem s tatus

The Redondo plant collection system includes approximately 114 miles of pipe and ser v es residential and associated commercial development. The sanitary collection system is separate from the storm drainage system. In the past during wet weather periods, flow increased from a monthly average base flow of around 2

- mgd up to 10

- mgd maximum daily flow. The District completed a comprehensive wastewater system plan in 1999. A collection system analysis found that Infiltration/Inflow (I/I) is a significant problem at this plant, and it recommended various I/I

and flow red uction programs. The District incorporated an I/I rehab program focusing on the

Redondo basin areas. No significant industrial users discharge to Redondo’s collection system.Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 8 of 73

T reatment p rocesses

The Redondo WWTP treatment process includes screening with m echanically cleaned bar screens, grit removal and com m inution, primary clarification, biological treatment using plastic media trickling filters, secondary clarification, and ultra violet disinfection. Solids are

process ed with primary and secondary anae robic digesters and a rotary press. The facility

heats s everal buildings onsite with digester off

- gas. A schematic of the treatment processes

is shown in Appendix D

. You can find basic information describing wastewater treatment processes included in a

b ooklet at the Water Environment Federation website at: http://www.wef.org/publicinformation/default.aspx

Staff

The Redondo plant is staffed five days a week from 6 : 3 0 a.m. to 5:00 p.m. Weeken d coverage consists of one operator for a period of two hours to conduct a facility inspection

and routine tasks. Redondo is a Class III plant

. There are five (5) certified operators and one (1) operator

- in

- training located at the Redondo WWTP . There ar e an additional five (5) certified operators in support roles that are available to work at Redondo WWTP if

necessary. Applicable monitoring data for Redondo WWTP are prepared by the laboratory at the District’s Lakota facility. The Lakota laboratory is currently staffed from 6 : 3 0 a

. m

. to
3: 0 0 p

. m

. , five days per week and weekends as needed.

Solid wastes

/Residual Solids

The treatment facilities remove solids during the treatment of the wastewater at the headworks (grit and screeni ngs), and at the primary and secondary clarifiers, in addition to incidental solids (rags, scum, and other debris) removed as part of the routine maintenance of the equipment. Redondo WWTP drains g rit, rags, and screenings which are transported for

ultima te dispos al at an approved local landfill. Waste s olids and scum removed from the primary and secondary clarifiers are treated by anaerobic digesters and dewater e d by rotary

press

. Dewatered sludge is normally trucked to a beneficial reuse facility in Eastern Washington for land appli cation under a permit from th e Department of Ecology (Permit No. BA0023451). Dewatered sludge can also be periodically trucked to a beneficial reuse composting facility in Kent, Washington

. T he composting faci lity is kept as a backup site when the disposal of Redondo WWTP biosolids via land application is not possible

. Discharge outfall

The secondary treated and disinfected effluent discharges from the facility into Puget

Sound

– Poverty Bay through outfall No .001

. The L akehaven Utility District extend ed the

Redondo WWTP outfall in 2008

. The existing 30

- inch outfall pipe extends 1,030 feet offshore to a depth of

- 123 feet MLLW and is connected to a ne w outfall line extension made

of a 24

- inch diameter high density polyethylene ( HDPE )

. The effluent discharge s through a single port (open

- ended pipe) at a distance of 2,670 feet offshore and a depth of

- 400 feet

MLLW. The primary incentive s for the outfall extension were to fix existing leaks and t o provide en hanced protection for the nearby geoduck beds

.Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 9 of 73

B. Description of the r eceiving w ater

Redondo WWTP effluent discharges to Puget Sound

– Poverty Bay . Other nearby point source

outfall s include the Lakota WWTP , located 2.6 miles southwest of Redondo, Midway (Des Moines) Sewer District WWTP located 5 miles north of Redondo WWTP, and various stormwater outfalls.

The ambient background data used for this permit includes the following from the ambient water

qu a lity monitoring station (EAP001) at East Passage

– SW of Three Tree Point just north of

Redondo ( link: http://www.ecy.wa.gov/apps/eap/marinewq/mwdataset.asp ):

Table 2

. Ambient Background Data

Parameter Value Used

Temperature ( 90 th percentile 1

- DADMax) 12.2 o C

Temperature (highest annual 1

- DADMax) 15.3 o C

pH (m inimum

, 90 th percentile , maximum ) 6.6, 8.1, 9 standard units

Dissolved Oxygen (average, 5 th percentile) 7.0 mg/L, 5.1 mg/L

Total Ammonia

- N (max.) 0.05 mg/L

Fecal Coliform (90 th percentile , maximum) 1 /100 mL , 5/100 mL

C. Wastewater i nfluent c haracterization

Redondo WWTP reported the concentration of influent pollutants in discharge monitoring reports.

The influent wastewater (data from January 2008 to December 2012) is characterized as follows:

Table 3 . Wastewater In fluent Characterization

Parameter Units Monthly Average Value Maximum Value

Biochemical Oxygen Demand (BOD 5 ) mg/L 247 325

BOD 5 lbs/day 5,334 7,670

Total Suspended Solids (TSS) mg/L 252 400

TSS lbs/day 5,497 9,900

D. Wastewater e ffluent c haracterization

Redondo WWTP reported the concentration of pollutants in the discharge in the permit application and in discharge monitoring reports. The tabulated data represents the quality of the wastewater effluent discharged from January 2008 to December 2012

. The wastewater effluent is characterized

as follows :

Table 4 . Wastewater Effluent Characterization

Parameter Units Monthly Average Value Ma ximum Value

Carbonaceous Biochemical Oxygen Demand (CBOD 5 ) mg/L 10 15

CBOD 5 lbs/day 237 590

TSS mg/L 19 26

TSS lbs/day 453 1,046Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 10 of 73

Parameter Units Maximum Monthly

G eometric M ean Maximum Weekly

G eometric M ean

Fecal Coliforms #/100 mL 179 443

Parameter Units Minimum Value Maximum Value

pH standard units 6 8

E. Summary of c ompliance with p revious p ermit i ssued July 31, 2008

The previous permit placed effluent limits on CBOD 5 , TSS, fecal coliform, pH, and chlorine.

Redondo WWTP has not consistently complied with the efflue nt limits and permit conditions throughout the duration of the permit issued on July 31, 2008 . Ecology assessed compliance

based on its review of the facility’s information in Ecology ’s Permitting and Repo rting Information System (PARIS), discharge monitoring reports (DMRs) and on inspections.

The following table summarizes the violations and permit triggers that occurred during the permit term. Permit triggers are not violations but rather when triggered require the permit holder to take an action defined in the permit.

Table 5

. Violations/Permit Triggers

Date Parameter Unit Value Max Limit Violation Category Violation

1/1/09 Eff luent TSS Lbs/d ay 2

, 279 2

, 102 Permit Violation Numeric effluent

violation

1/1/09 E f fluent

TSS Removal % 82.2 85 Permit Violation Numeric effluent

violation

12/1/10 Effluent Fecal

Coliform #/100 mL 443 400 Permit Violation Numeric effluent

violation

The following table summarizes compliance with report submittal requirements over the permit term. There w as one late submittal

.

Table 6

. Permit Submittals

Submittal ‘Name Due Date Received Date

Toxicity

- Chronic S ummary Report 6/30/12 6/1/12

Toxicity

- Chronic S ummary Report 12/15/12 12/3/12

I nfiltration and Inflow Evaluation 3 / 31 / 11 5 / 24 /1 1

Toxicity

- Acute S ummary Report 9 / 30 /12 9 / 1 /12

Application for Permit Renewal 1 / 31 /1 3 1 / 8 /1 3

Operation and Maintenance Manual 10 / 31 /1 0 10 / 29 /1 0

Sediment Sampling and Analysis Plan 3 / 31 /1 0 3 / 2 /1 0

Signatory Requirements 9 / 10 / 08 9 / 10 / 08Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 11 of 73

F. S tate e nvironmental p olicy a ct (S EPA ) c ompliance

State law exempts the issuance, reissuance or modification of any wastewater discharge permit from the SEPA process as long as the permit conta ins conditions are no less stringent than federal and state rules and regulations (RCW 43.21C.0383). The exemption applies only to existing discharges, not to new discharges.



### III. P roposed Permit Limits

Federal and s tate regulations require that effluent limits in an NPDES permit must be either

tec hnology

- or water quality

- based

.

 Technology

- based limits are based upon the treatment methods available to treat specific pollutants. Technology

- based limits are set by the EPA and published as a regula tion, or Ecology develops the limit on a case

- by

- case basis (40 CFR 125.3, and chapter 173

- 220 WAC).

 Water quality

- based limit s are calculated so that the effluent will comply with the Surface Water Quality Standards ( c hapter 173

- 201A WAC), Ground Water Standards ( c hapter

173

- 200 WAC), Sediment Quality Standards ( c hapter 173

- 204 WAC)

, or the National Toxics Rule (40 CFR 131.36).

 Ecology must apply the most stringent of these limits to each parameter of concern. These

limits are described below.

The li mits in this permit reflect information received in the application and from supporting reports (engineering, hydrogeology, etc.). Ecology evaluated the permit application and determined the limits needed to comply with the rules adopted by the s tate of Washington. Ecology does not develop effluent limits for all reported pollutants . Some pollutants are not treatable at the concentrations reported, are not controllable at the source, are not listed in regulation, and do not have a reasonable potential t o cause a water quality violation.

Ecology does not usually develop limits for pollutants not reported in the permit application but may be present in the discharge. T he permit does not authorize discharge of the non

- reported pollutants. During the fiv e

- year permit term, the facility’s effluent discharge conditions may change from those conditions reported in the permit application. The facility must notify Ecology if significant changes occur in any constituent [40 CFR 122.42(a)]

. Until Ecology modifi es the permit to reflect additional discharge of pollutants, a permitted facility could be violating its permit.

A. Design criteria

Under WAC 173

- 220

- 150 (1)(g), flows and waste loadings must not exceed approved design

criteria. Ecology approved design criteria for this facility’s treatment plant in the design drawings ( HDR Engineering

, November, 1987 )

. The table below includes design criteria from the referenced report.Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 12 of 73

Table 7

. Design Criteria for Redondo WWTP

Parameter Design Quantity

Maximum Month Design Flow (MMDF) 5.6 MGD

BOD 5 Loading for Maximum Month 9,760 lb/day

TSS Loading for Maximum Month 11,710 lb/day

B. T echnology

- b ased e ffluent l imit s

Federal and state regulations define technology

- based effluent limits for municipal wastewater treatment plants. These effluent limits are given in 40 CFR Part 133 (federal) and in chapter 173

- 221 WAC (state). These regulations are performance standards that constitute all known, available, and reasonable m ethods of prevention, control, and treatment (AKART) for municipal wastewater.

The table below identifies technology

- based limits for pH, fecal coliform, C BOD 5 , and TSS, as listed in chapter 173

- 221 WAC. Section III.F this fact sheet describes the potentia l for water quality

- based limits.

Table 8

. Technology

- based Limits

Parameter Average Monthly Limit Average Weekly Limit

C BOD 5 (concentration) 25 mg/L 4 0 mg/L

C BOD 5 (concentration) In addition

, the C BOD 5 effluent concentration must not exceed fifteen

percent (15%) of the average influent concentration

. TSS (concentration) 30 mg/L 45 mg/L

TSS (concentration) In addition

, the TSS effluent concentration must not exceed fifteen percent

(15%) of the average influent concentration

.

Parameter Monthly Geometric Mean Limit Weekly Geometric Mean Limit

Fecal Coliform 200 organisms/100 mL 400 organisms/100 mL

Parameter Daily M inimum Daily Maximum

pH 6.0 standard units 9.0 standard units

Ecology derived t he technology

- based monthly average limit for chlorine from standard operating practices. The Water Pollution Control Federation's Chlorination of Wastewater (1976) states that a properly designed and maintained wastewater treatment plant can achieve adequate disinfection if a 0.5 mg/L chlorine residual is maintained after fifteen minutes of contact time. See also Metcalf and Eddy, Wastewater Engineering, Trea tment, Disposal and

Reuse , Third Edition, 1991. A treatment plant that provides adequate chlorination contact time can meet the 0.5 mg/L chlorine limit on a monthly average basis. According to WAC

173

- 221

- 030(11)(b), the corresponding weekly average is 0.75 mg/L.Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 13 of 73

Redondo WWTP disinfects with UV and only uses chlorine as a backup. The previous permit ha d water

- quality based chlorine limit s of 120  g/L (average monthly limit) and 312

 g/L ( maximum daily limit) based on dilution factors (24 acute and 225 c hronic) associated

with the old outfall diffuser design

, and the facility was able to comply with these limits

. The water

- quality based chlorine limit s associated with the dilution factors (79 acute and 182
chronic) of the new outfall are 394  g/L (averag e monthly limit) and 1,031  g/L (maximum daily limit)

. Since the WWTP could comply with the more stringent limits in the previous permit, and to avoid anti

- backsliding, t he chlorine limits in the previous permit 120  g/L (average monthly limit) and 312  g/L (maximum daily limit) will be retained for the proposed permit. The chlorine limits only apply when chlorine is being used as a

disinfectant.

Technology

- based mass limits are based on WAC 173

- 220

- 130(3)(b) and 173

- 221

- 030(11)(b). Ecology calculated the monthly and weekly average mass limits for CBOD 5 and Total Suspended Solids as follows:

Mass Limit = CL x DF x CF

where:

CL = Technology

- based concentration limits listed in the above table

DF = Maximu m Monthly Average Design flow ( MGD)

CF = Conversion factor of 8.34

Table 9

. Technology

- based Mass Limits

Parameter Concentration Limit (mg/L) Mass Limit (lbs/day)

CBOD 5 Monthly Average 25 1,168

CBOD 5 Weekly Average 40 1,868

TSS Monthly Average 30 1,401

TSS Weekly Average 45 2,102

C. Surface w ater q uality

- b ased e ffluent l imit s

The Washington State surface water quality standards ( c hapter 173

- 201A WAC) are designed to protect existing water quality and preserve the beneficial uses of Washington 's

surface waters. W aste discharge permits must include conditions that ensure the discharge

will meet the s urface w ater q uality s tandards (WAC 173

- 201A

- 510 )

. W ater quality

- based

effluent limits may be based on an individual waste load allocation or on a waste load

allocatio n developed during a basin wide total maximum daily load study (TMDL).

Numerical criteria for the protection of aquatic life and recreation

Numerical water quality criteria are listed in the water quality standards for surface waters ( c hapter 173

- 201A WAC) . They specify the maximum levels of pollutants allowed in receiving water to protect aquatic life and recreation in and on the water

. Ecology usesFact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 14 of 73

n umerical criteria along with chemical and physical data for the wastewater and receiving

water to derive the effluent limits in the discharge perm it. When surface water quality

- based limits are more stringent or potentially more stringent than technology

- based limits

, the discharge must meet the water quality

- based limits

. Numerical criteria for the protection of human health

The U.S. EPA has published 91 numeric water quality criteria for the protection of human health that are applicable to dischargers in Washington State (EPA

, 1992). These criteria are designed to protect humans from exposure to pollutants linked to cancer and other disease s
, based on consuming fish and shellfish and drinking contaminated surface waters. The water quality s tandards also include radionuclide criteria to protect humans from the effects of

radioactive substances.

Na rrative criteria

Narrative water quality criteria (e.g., WAC 173

- 201A

- 240(1); 2006) limit the toxic, radioactive, or other deleterious material concentrations that the facility may discharge to levels below those which have the potential to:

• Adversely affe ct designated water uses.

• Cause acute or chronic toxicity to biota.

• Impair aesthetic values.

• Adversely affect human health.

Narrative criteria protect the specific designated uses of all fresh waters (WAC 173

- 201A

- 200, 2006) and of all marine waters (W AC 173

- 201A

- 210

, 2006) in the

s tate of Washington.

Antidegradation

Description

-- The purpose of Washington's Antidegradation Policy (WAC 173

- 201A

- 300

- 330; 2006) is to:

• Restore and maintain the highest possible quality of the surface waters of Washington.

• Describe situations under which water quality may be lowered from its current condition.

• Apply to human activities that are likely to have an impact on the water quality of surface

water.

• Ensure that all human activities likely to contribute to a lowering of water quality, at a minimum, apply all known, available, and reasonable methods of prevention, control, and treatment (AKART).

• Apply three t iers of protection (described below) fo r surface waters of the state.

Tier I ensure s existing and designated uses are maintained and protected and applies to all waters and all sources of pollutions. Tier II ensure s that waters of a higher quality than the criteria assigned are not degraded unless such lowering of water quality is necessary and in the overriding pub lic interest. Tier II applies only to a specific list of polluting activities.

Tier III prevent s the degradation of waters formally listed as "outstanding resource waters," and applies to all sources of pollution.Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 15 of 73

A facility must prepare a Tier II analys is when a ll three of the following conditions are met :

• The facility is planning a new or ex panded action

.

• Ecology regulates or authorizes the action.

• The action has the potential to cause measurable degradation to existing water quality at the edge of a c hronic mixing zone.

Facility Specific Requirements

-- This facility must meet Tier I requirements.

• Dischargers must maintain and protect existing and designated uses

. Ecology must not allow any degradation that will interfere with, or become injurious to, existing or designated uses, except as provided for in chapter 173

- 201A WAC

. Ecology’s analysis described in this section of the fact sheet demonstrates that the proposed permit conditions will protect existing an d designated uses of the receiving water

. Mixing z ones

A mixing zone is the defined area in the receiving water surrounding the discharge port(s), where wastewater mixes with receiving water. Within mixing zones the pollutant concentrations may exceed wat er quality numeric standards, so long as the discharge doesn’t

interfere with designated uses of the receiving water body ( for example

, recreation, water supply , and aquatic life and wildlife habitat , etc .) The pollutant concentrations outside of the

mixi ng zones must meet water quality numeric standard s.

State and federal rules allow mixing zones because the concentrations and effects of most pollutants diminish rapidly after discharge, due to dilution. Ecology defines mixing zone

sizes to limit the amou nt of time any exposure to the end

- of

- pipe discharge could harm water quality, plants, or fish.

The state’s water quality standards allow Ecology to authorize mixing zones for the facility’s permitted wastewater discharges only if those discharges already receive all known, available, and reasonable methods of prevention, control

, and treatment (AKART). Mixing zones typically require compliance with water quality criteria within a specified distance from the point of discharge and must not use more than 25 % of the available width of the water body for dilution [ WAC 173

- 201A

- 400 (7)(a)(ii

- iii) ]

. Ecology uses modeling to estimate the amount of mixing within the mixing zone. Through modeling Ecology determine s the potential for violating the water quality standards at the edge of the mixing zone and derive s any necessary effluent limit s . Steady

- state models are the most frequently used tools for conducting mixing zone analyses. Ecology chooses values

for each effluent and for receiving water variable s that correspond to the time period when

the most critica l condition is likely to occur (see Ecology’s Permit Writer’ s Manual ). Each critical condition parameter

, by itself

, has a low probability of occurrence and the resulting

dilution fac tor is conservative. The term “ reasonable worst

- case ” applies to these values.

The mixing zone analysis produces a numerical value called a dilution factor (DF)

. A

d ilution factor represents the amount of mixing of effluent and receiving water that occurs at the boundary of the mixing zone. For example, a dilution factor of 10 means the effluent is 10% and the receiving water is 90% of the total volume of water at the boundary of the mixing zone

. Ecology uses d ilution factor s with the water quality criteria to c al culateFact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 16 of 73

reasonable potentials and effluent limits. Water quality standards include both aquatic life

based criteria and human health

- based criteria. The former are applied at both the a cute and chronic mixing zone boundaries ; the latter are applied only at the chronic boundary. The concentration of pollutants at the boundar ies of any of these mixing zones may not exceed

the numerical criteria for that zone.

Each aquatic life acute criteri on is based on the assumption that organisms are not exposed to

that concentration for more than one hour and more often than one exposure in three years. Each aquatic life chronic criteri on is based on the assumption that organisms are not expose d

to that concentration for more than four consecutive days and more often than once in three

years.

The two types of human health

- based water quality criteria distinguish between those pollutants linked to non

- cancer effects (non

- carcinogenic) and those linked to cancer effects (carcinogenic). The human health

- based water quality criteria incorporate several exposure and risk assumptions. These assumptions include:

• A 70

- year lifetime of daily exposures

.

• A n ingestion rate for fish or shellfish measured in kg/day

.

• A n ingestion rate of two liters/day for drinking water

.

• A one

- in

- one

- million cancer r isk for carcinogenic chemicals.

This permit authorizes a small acute mixing zone, surrounded by a chronic mixing zone around the point of discharge ( WAC 173

- 201 A

- 400 ). The water quality standards impose certain conditions before allowing the discharger a mixing zone:

1. Ecology must specify both the allowed size and location in a permit.

Th e proposed permit specifies the size and location of the allowed mixing zone (as specified below)

.
2. The facility must f

ully apply “all known

, available

, and reasonable methods of prevention, control and treatment” (AKART) to its discharge

. Ecology has determined that the treatment provided at Redondo WWTP meet s the requirements of AKART (see “Technology

- based Limits ”).

3. Ecology must c onsider critical discharge condition s

. Surface water quality

- based limits are derived for the water body’s critical condition ( the receiving water and waste discharge condition with the highest potential for adverse impact on the aquatic biota, human health, and existing or designated water body uses )

. The critical discharge condition is of ten pollutant

- specific or water body

- specific.

Critical discharge conditions are those conditions that result in reduced dilution or increased effect of the pollutant . Factors affecting dilution include the depth of water, the density stratification in the water column, the currents

, and the rate of discharge. Density stratification is determined by the salinity and temperature of the receiving water. Temperatures are warmer in the surface waters in summer. Therefore, density stratification is generally greatest during the summer months. Density stratification affects how far up in the water col um n a freshwater plume may rise . The rate of mixingFact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 17 of 73

is greatest when an effluent is rising

. The effluent stops rising when the mixed effluent is the same density as the surrounding water. After the effluent stops rising , the rate of mixing is much more gr adual. Water depth can affect dilution when a plume might rise

to the surface when there is little or no stratification. Ecology uses the water depth at mean lower low water (MLLW) for marine waters

. Ecology’s Permit Writer’s Manual

describes additional guidance on criteria/design conditions for dete rmining dilution

factors. The m anual can be obtained from Ecology’s website at: https://fortress.wa.gov/ecy/publications/SummaryPages /92109.html

.

Table 10

. Critical Conditions Used to Model the Discharge

Critical Condition Value

Water depth at MLLW 400 feet

Densit y profile with a difference of 0.76 sigma

- t units between

- 400 ( MLLW ) feet and the surface

10 th percentile current speeds for acute mixing zone 0.38 ~ 0.54 c m/sec

50th percentile current speeds for chronic and human health mixing zones 1.96 ~ 2.81 c m/sec

Maximum average monthly effluent flow for chronic and human health

non

- carcinogen 5.6 MGD

Maximum daily flow for acute mixing zone 10 MGD

1 DAD MAX e ffluent temperature 20.9 degrees C

Ecology obtained ambient data at critical conditions in the vicinity of the outfall from an outfall engineering report by Cosmopolitan Engineering Group in 2005

.
4. Supporting information must clearly indicate the mixing zone would not:

• H ave a reasonable potential to cause the loss of sensitive or important habitat.

• S ubstantially interfere with the existing or characteristi c uses.

• R esult in damage to the ecosys tem

.

• A dversely affect public health.

Ecology established Washington State water quality criteria for toxic chemicals using EPA criteria. EPA developed the criteria using toxicit y tests with numerous organisms

and set the criteria to generally protect the species tested and to fully protect all commercially and recreationally important species

.

EPA sets a cute criteria for toxic chemicals assuming organisms are exposed to the pollutant at the criteria concentration for one hour. They set chronic standards assuming organisms are exposed to the pollutant at the criteria concentration for four days

. D ilution modeling under critical conditions generally shows that both acute and chronic

criteria concentrations are reached within minutes of discharge

.

T he di scharge plume does not impact d rifting and non

- strong swimming organisms because they cannot stay in the plume close to the outfall long enough to be affected. Strong swimming fish could maintain a position within the plume, but they can also

avoid the di scharge by swimming away

. M ixing zone s generally do not affect b enthic organisms (bottom dwellers) because the buoyant plume rises in the water column.Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 18 of 73

Ecology has additionally determined that the effluent will not exc eed 33 degrees C for

more than two s econds after discharge; and that the temperature of the water will not create lethal conditions or blockages to fish migration.

Ecology evaluates the cumulative toxicity of an effluent by testing the discharge with

w hole effluent toxicity (WET) testing.

5. T he discharge/receiving water mixture must not exceed w ater quality criteria outside the boundary of a mixing zone.

Ecology conducted a reasonable potential analysis, using procedures established by the

EPA and by Ecology , f

or each pollutant and concluded the discharge/receiving water

mixture will not violate water quality criteria outside the boundary of the mixing zone if permit limits are met

.
6. The size of the mixing zone and the concentrations of the pollutants must be

minimized.

At any given t ime, the effluent plume uses only a portion of the acute and chronic mixing zone, which minimizes the volume of water involved in mixing. Because tidal currents change direction, the plume orientation within the mixing zone changes

. The plume

mixes as it rises throu gh the water column therefore much of the receiving water volume at lower depths in the mixing zone is not mixed with discharge . Similarly, because the discharge may stop rising at some depth due to density stratification, waters above that depth will not mix with the discharge

. Ecology determined i t is impractical to specify in the permit the actual, much more limited volume in which the dilution occurs as the plume rises and moves with the current.

Ecology minimizes the size of mixing zo nes by requiring dischargers to install diffusers when they are appropriate to the discharge and the specific receiving waterbody. When a

diffuser is installed

, the discharge is more completely mixed with the receiving water in a

shorter time. Ecology al so minimizes the size of the mixing zone (in the form of the dilution factor) using design criteria with a low probability of occurrence. For example, Ecology uses the expected 95th percentile pollutant concentration, the 90th percentile background concen tration, the centerline dilution factor

, and the lowest flow occurring once in every ten years to perform the reasonable potential analysis.

Because of the above reasons, Ecology has effectively minimized the size of the mixing zone authorized in the prop osed permit

.

7. Maximum size of mixing zone

. The authorized mixing zone does not exceed the maximum size restriction.

8. Acute m ixing z one

.

• The discharge/receiving water mixture must comply with acute criteria as near to the point of discharge as practicably att ainable.

Ecology determined the acute criteria will be met at 10% of the distance of the chronic mixing zone

.Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 19 of 73

• The pollutant concentration, duration, and frequency of exposure to the discharge will not create a barrier to migration or translocation of indigenous organisms to a degree that has the potential to cause damage to the ecosystem.

As described above, the toxicity of any pollutant depends upon the exposure, the pollutant concentration, and the time the organism is exposed to that concentration. Authorizing a limited acute mixing zone for this discharge assures that it will not create a barrier to migration. The effluent from this discharge will rise as it enters the receiving water, assuring that the rising effluent will not cause translocation of indigenous organisms near the point of discharge (below the rising effluent).

• Comply with size restrictions.

The mixing zone authorized for this discharge complies with the size restrictions published in chapter 173

- 201A WAC.

9. Overlap of mixing zones

. This mixing zone does not overlap another mixing zone

.

D. Designated u ses and s urface w ater q uality c riteria

Applicable designated uses and surface water quality criteria are defined in c hapter

173

- 201A WAC. In addition, the U.S. EPA set human health crit eria for toxic pollutants (EPA 1992). The table s included below summarize the c riteria applicable to the receiving water’s designated uses

.

• Aquatic life uses are designated using the following general categories. All indigenous

fish and non

- fish aquatic species must be protected in waters of the state.

a. Extraordinary quality salmonid and other fish migration, rearing, and spawning; clam, oyster, and mussel rearing and spawning; crustaceans and other shellfish (crabs, shrimp, crayfish, scallops, etc.) reari ng and spawning.

b. Excellent quality salmonid and other fish migration, rearing, and spawning; clam, oyster, and mussel rearing and spawning; crustaceans and other shellfish (crabs, shrimp, crayfish, scallops, etc.) rearing and spawning.

c. Good quality salmoni d migration and rearing; other fish migration, rearing, and spawning; clam, oyster, and mussel rearing and spawning; crustaceans and other shellfish (crabs, shrimp, crayfish, scallops, etc.) rearing and spawning.

d. Fair quality salmonid and other fish migra tion.

The Aquatic Life Uses and the associated criteria for this receiving water are identified

below.Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 20 of 73

Table 11

. Marine Aquatic Life Uses and Associated Criteria

Extraordinary Quality

Temperature Criteria

– Highest 1D MAX 13°C (55.4°F)

Dissolved Oxygen Criteria

– Lowest 1

- Day

Minimum 7.0 mg/L

Turbidity Criteria • 5 NTU over background when the background is 50 NTU or less; or

• A 10 percent increase in turbidity when the background turbidity is more than 50 NTU.

pH Criteria pH must be within the range of 7.0 to 8.5 with a

human

- caused variation within the above range of

less than 0.2 units.

• To protect shellfish harvesting, fecal coliform organism levels must not exceed a geometric mean value of 14 colonies/100 mL, a nd not have more than 10 percent of all samples (or any single sample when less than ten sample points exist) obtained for calculating the geometric mean value exceeding 43 colonies/100 mL.

• The recreational uses are primary contact recreation and secondary contact recreation.

The recreational use for this receiving water is primary contact recreation as identified below.

Table 12

. Recreational Uses

Recreational U se Criteria

Primary Contact

Recreation Fecal coliform organism levels must not exceed a geometric mean value of 14

colonies/100 mL, with not more than 10 percent of all samples (or any single sample when less than ten sample points exist) obtained for calculating the geometric mean value exceeding 43 colonies /100 mL.

• The miscellaneous marine water uses are wildlife habitat, harvesting, commerce and navigation, boating, and aesthetics.

E. Water q uality i mpairments

Ecology has not documented any water quality impairments in the receiving water in the vicinity of the outfall.

F. Evaluation of s urface w ater q uality

- b ased e ffluent l imits for n umeric c riteria

Pollutants in an effluent may affect the aquatic environment ne ar the point of discharge (near

- field) or at a considerable distance f rom the point of discharge (far

- field). Toxic pollutants, for exam ple, are near

- field pollutants ; their adverse effects diminish rapidly with mixing in the receiving water. Conversely

, a pollutant such as bio chemical oxygen demand (BOD 5 ) is a far

- field pollutant whose adverse effect oc curs away from the discharge even after dilution has occurred. Thus, the method of ca lculating surface water quality

- based effluent limits varies with the point at which the pollutant has its maximum effect.Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 21 of 73

With technology

- based controls (AKART), predic ted p ollutant concentrations in the discharge exceed water quality criteria. Ecology therefore authorizes a mixing zone in accordance with the geometric configuration, flow restriction, and other restrictions imposed on mixing zones by c hapter 173

- 201A WA C.

The Outfall No. 001 has 2,670 feet long outfall pipe with a diameter of 24 inches

, and is

open

- ended

. T he mean lower low water (MLLW) depth is 400 feet. Ecology obtained this

information from the Outfall Engineering R eport submitted by Cosmopolitan Eng ineering Group in 2005

. Chronic Mixing Zone

-- WAC 173

- 201A

- 400(7)(b) specifies that mixing zones must not extend in any horizontal direction from the discharge ports for a distance greater than 200 feet plus the depth of water over the discharge ports and may not occupy more than 25% of the width of the water body as measured during MLLW.

The horizontal distance of the chronic mixing zone is 1,200 feet. The mixing zone extends from the top of the discharge ports to the water surface.

Acute Mixing Zon e

-- WAC 173

- 201A

- 400(8)(b) specifies that in estuarine waters a zone where acute criteria may be exceeded must not extend beyond 10% of the distance established for the chronic zone. The acute mixing zone for Outfall No. 001 extends 60 feet in any direction from any discharge port.

Ecology reviewed t he dilution factors that occur within these zones at the critical condition using U.S. EPA’s UM3 Model . The dilution factors are listed below.

Table 13

. Dilution Factors (DF)

Criteria Acute Chronic

Aquatic Life 79 : 1 182: 1

Human Health, Carcinogen 182: 1

Human Health, Non

- carcinogen 182: 1

Ecology determined the impacts of dissolved oxygen deficiency, nutrien ts, pH, fecal coliform, ammonia, metals, other toxics, and temperature as described below, using the

dilution factors in the above table. The derivation of surface water quality

- based limits also takes into account the variability of pollutant concentrations in both the eff luent and the receiving water.

Dissolve d Oxygen

-- BOD 5 and Ammonia Effects

-- Natural decomposition of organic

material in wastewater effluent impact s dissolved oxygen in the receiving water at distances

far outsid e of the regulated mixing zone. The 5

- day Biochemical Oxygen Demand (BOD 5 )

of an effluent sample indicates the amount of biodegradable material in the wastewater and estimates the magnitude of oxygen consumption the wastewater will g enerate in the receiving

water. The amount of ammonia

- based nitrogen in the wastewater also provides an indication of oxygen demand potential in the receiving water.

With technology

- based limits, this discharge results in a small amount of biochemical oxygen demand ( BOD 5 ) relative to the large amount of dilution in the receiving water at

critical condition s. Technology

- based limits will ensure that dissolved oxygen criteria are met in the receiving water.Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 22 of 73

pH

-- Compliance with the technology

- based limits of 6.0 to 9.0 will assure compliance with the water quality standards of surface waters because of the hi gh buffering capacity of marine

water.

Fecal Coliform

-- Ecology modeled the number s of fecal coliform by simple mixing analysis using the technology

- based limit of 400 organisms per 100 m L and a dilution factor of 182.

Under critical conditions, modeling predicts no violation of the water quality criterion for fecal coliform. Therefore, the proposed permit includes the technology

- based effluent limit

for fecal coliform bacteria.

Turbidity

-- Ecology evaluated the impact of turbidity based on the range of total suspended solids in the effluent and turbidity of the receiving water. Ecology expects no violations of the turbidity criteria outside the designated mixing zone provided the facility meets its technology

- based total suspended solids permit limits.

Toxic Pollutants

-- Federal regulations (40 CFR 122.44) require Ecology to place limits in NPDES permits on toxic chemicals in an effluent whenever there is a reasonable potential for those chemicals to exceed the surface water quality criteria. Ecology doe s not exempt facilities with technology

- based effluent limits from meeting the surface water quality standards.

The following toxic pollutants are present in the discharge: chlori ne, ammonia, and heavy metals (arsenic, cadmium, chromium, copper, lead, mer cury, nickel, selenium, and zinc )

, bis (2

- ethylhexyl phthalate), and butyl b enzyl phthalate . Ecology conducted a reasonable potential analysis (See Appendix D ) on these parameters to determine whether it would require effluent limits in this permit.

Ammo nia's toxicity depends on that portion which is available in the unionized form. The amount of unionized ammonia depends on the temperature, pH, and salinity of the receiving

marine water. To evaluate ammonia toxicity, Ecology used the available receivin g water
information for ambient station, the Ecology Marine Water Quality Monitoring Station

EAP001 and Ecology spreadsheet tools.

No valid ambient background data were available for chlori ne and heavy metals (arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, and zinc )

, bis (2

- ethylhexy l phthalate), and butyl b enzyl phthalate

. Ecology used zero for background.

Ecology determined that chlorine, ammonia, and heavy metals (ars enic, cadmium, chromium, copper, lead, mercury, nickel, selenium, and zinc )

, bis (2

- ethylhexy l phthalate) and butyl b enzyl phthalate pose no reasonable potential to exceed the water quality criteria at the critical condition using procedures given in EPA, 1991 ( Appendix D ) and as described above. Ecology’s determination assumes that this facility meets the other effluent limits of this permit.

Temperature

-- The state temperature standards [ WAC 173

- 201A

- 200

- 210 and 600

- 612 ] include multiple elements:

• Annual summer maximum threshold criteria (June 15 to September 15)

.

• Supplemental spawning and rearing season criteria (September 15 to June 15)

.

• Incremental warming restrictions

.

• Protections against acute effects

.Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 23 of 73

Ecology evaluates each criterion independently to determine reasonable potential and derive permit limits.

• Annual summer maximum and supplementary spawning/rearing criteria

Each water body has an annual maximum temperature criterion [ WAC 173

- 201A

- 200(1)(c), 210(1)(c), and Table 602]. These threshold cr iteria (e.g., 12, 16, 17.5, 20°C) protect specific categories of aquatic life by controlling the effect of human actions on summer

temperatures.

Some waters have an additional threshold criterion to protect the spawning and incubation of salmonids (9°C fo r char and 13°C for salmon and trout) [WAC 173

- 201A

- 602, Table 602]. These criteria apply during specific date

- windows.

The threshold criteria apply at the edge of the chronic mixing zone. Criteria for most fresh waters are expressed as the highest 7

- Day average of daily maximum temperature (7

- DADMax). The 7

- DADMax temperature is the arithmetic average of seven consecutive measures of daily maximum temperatures. Criteria for marine waters and some fresh waters are expressed as the highest 1

- Day annual maximum temperature (1

- DMax).

• Incremental warming criteria

The water quality standards limit the amount of warming human sources can cause under specific situations [WAC 173

- 201A

- 200(1)(c)(i)

- (ii), 210(1)(c)(i)

- (ii)]. The incremental warming criteria ap ply at the edge of the chronic mixing zone.

At locations and times when background temperatures are cooler than the assigned threshold criterion, point sources are permitted to warm the water by only a defined increment. These increments are permitted onl y to the extent doing so does not cause temperatures to exceed either the annual maximum or supplemental spawning criteria.

At locations and times when a threshold criterion is being exceeded due to natural conditions, all human sources, considered cumulat ively, must not warm the water more than 0.3°C above the naturally warm condition.

When Ecology has not yet completed a TMDL, our policy allows each point source to warm water at the edge of the chronic mixing zone by 0.3°C. This is true regardless of the background temperature and even if doing so would cause the temperature at the edg e of a standard mixing zone to exceed the numeric threshold criteria. Allowing a 0.3°C warming for each point source is reasonable and protective where the dilution factor is based on 25% or less of the critical flow. This is because the fully mixed effe ct on temperature will only be a fraction of the 0.3°C cumulative allowance (0.075°C or less)

for all human sources combined.

• Protections for temperature acute effects

Instantaneous lethality to passing fish: The upper 99 th percentile daily maximum efflue nt temperature must not exceed 33°C

, unless a dilution analysis indicates ambient temperatures will not exceed 33°C two seconds after discharge.

General lethality and migration blockage: Measurable (0.3°C) increases in temperature at the edge of a chronic mixing zone are not allowed when the receiving water temperature

exceeds either a 1DMax of 23°C or a 7DADMax of 22°C.Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 24 of 73

Lethality to incubating fish: Human actions must not cause a measurable (0.3°C) warming above 17.5°C at locations where eggs are incubat ing.

Reasonable Potential Analysis

Annual summer maximum and incremental warming criteria: Ecology calculated the reasonable potential for the discharge to exceed the annual summer maximum and the incremental warming criteria at the edge of the chronic mixing zone during critical condition. No reasonable potential exists to exceed the temperature criterion where:

(Criterion + 0.3) > [Criterion + (Teffluent95

– Criterion)/DF].

The figure below graphically portrays the above equation and shows the conditi ons when a permit limit will apply.

Figure 2

. Dilution Necessary to Meet Criteria at Edge of Mixing Zone

(13 + 0.3) > ( 13 + ( 23

– 13 )/ 282) => 13.3 > 13.035

Therefore, the proposed permit does not include a temperature limit

. The permit requires additional monitoring of the effluent. Ecology will reevaluate the reasonable potential during the next permit cycle.

G. Human h ealth

Washington’s water quality standards include 91 numeric human health

- based criteria that Ecology mus t consider when writing NPDES permits. These criteria were established in

1992 by the U.S. EPA in its National Toxics Rule (40 CFR 131.36). The National Toxics

Rule allows states to use mixing zone s to evaluate whether discharges comply with human

health criteria. 0 10 20 30 40 50 60 70

9 11 13 15 17 19 21 23 25 27 29 31 33 Minimum Chronic Dilution Factor needed to meet numeric WQ criteria

95 th Percentile Effluent Temperature, ° C

WQ Criteria =

9

WQ Criteria =

12 Calculation based on:Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 25 of 73

Ecology determined the effluent may contain chemicals of concern for human health

, based

on (1) the facility’s status as an EPA major discharger and (2) data or information indicat ing the discharge contains regulated chemic als

.

Eco logy evaluated the discharge's potential to violate the water quality standards as required by 40 CFR 122.44(d) by following the procedures published in the Technical Support Document for Water Quality

- Based Toxics Control (EPA/505/2

- 90

- 001) and Ecology's

Permit Writer's Manual to make a reasonable potential determination. The evaluation

showed that the discharge has no reasonable potential to cause a violation of water quality standards, and an effluent limit is not needed

.

H. Sediment q uality

The aquat ic sediment standards ( c hapter 173

- 204 WAC) protect aquatic biota and human

health. Under t hese standards Ecology may require a facility to evaluate the potential for its discharge to cause a violation of sediment standards (WAC 173

- 204

- 400). You can obt ain

additional information about sediments at the Ecology Aquatic Lands Cleanup Unit website. http://www.ecy.wa.gov/programs/tcp/smu/sediment.html

In August 2009, a sampling event occurred to provide baseline sediment data near the new

outfall which was installed in 2008. No SMS chemical exceedances were found in the six samples analyzed and the one bioassay sample passed the SMS biological criteria

. Ecology’s Aquatic Lands Cleanup Unit recommends sampling at Redondo’s new outfall again to assess

sediment conditions from the baseline conditions. The proposed permit requires a sediment sampling and analysis plan and a subsequent sediment data report

. According to Ecology’s Aquatic Cleanup Lands Unit, if no SMS exceedances are found during this permit cycle, monitoring would continue at a rate of every other permit cycle.

I. Whole e ffluent t oxicity

The water quality standards for surface waters forbi d discharge of effluent that has the potential to cause toxic effects in the receiving waters. Many toxic pollutants cannot be measured by commonly available detection methods. However, laboratory tests can measure toxicity directly by exposing living or ganisms to the wastewater and measuring their responses. These tests measure the aggregate toxicity of the whole effluent, so this approach is called whole effluent toxicity (WET) testing. Some WET tests measure acute toxicity and

other WET tests measure chronic toxicity.

• Acute toxicity tests measure mortality as the significant response to the toxicity of the effluent. Dischargers who monitor their wastewater with acute toxicity tests find early indications of any potential lethal effect of the effluent on organisms in the receiving water.

• Chronic toxicity tests measure various subletha l toxic responses, such as reduced growth or reproduction. Chronic toxicity tests often involve either a complete life cycle test on an organism with an extremely short life cycle, or a partial life cycle test during a critical stage of a test organism's life. Some chronic toxicity tests also measure survival.

Laboratories accredited by Ecology for WET testing know how to use the proper WET testing protocols, fulfill the data requirements, and submit results in the correct reporting format.

Accredited la boratory staff know how to calculate an NOEC, LC50, EC50, IC25, etc. Ecology gives all accredited labs the most recent version of Ecology Publication No. WQ

- R

- 95

- 80,Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 26 of 73

Laboratory Guidance and Whole Effluent Toxicity Test Review Criteria ( https://fortress.wa.gov/ecy/publications/SummaryPages /9580.html ) which is referenced in the permit. Ecology recommends that each regulated facility send a copy of the acute or chronic toxicity sections(s) of its NPDES per mit to the laboratory.

Acute Toxicity

The previous permit required the Redondo WWTP to perform acute WET tests twice during the permit term. Both of the July 2012 acute tests (fathead minnow and daphnid) had less

than 65% survival in 100% effluent. There fore, Redondo needs another effluent

characterization for acute WET.

Chronic Toxicity

The previous permit required the Redondo WWTP to perform chronic WET tests twice during the permit term. WET testing conducted during effluent characterization showed no reasonable potential for effluent discharges to cause receiving water chronic toxicity because there was no statistically significant toxicity at the ACEC of 4.17% effluent. Therefore, the

p roposed permit will not impose a chronic WET limit. Redondo WWTP must re

- test the effluent before submitting an application for permit renewal.

• If this facility makes process or material changes which, in Ecology's opinion, increase the potential for eff

luent toxicity, then Ecology may (in a regulatory order, by permit modification, or in the permit renewal) require the facility to conduct additional effluent

characterization

. Redondo WWTP may demonstrate to Ecology that effluent toxicity has

not increas ed by performing additional WET testing after the process or material changes

have been made.

• If WET testing conducted for submittal with a permit application fails to meet the performance standards in WAC 173

- 205

- 020, Ecology will assume that effluent to xicity

has increased and require another effluent characteriza tion in accordance with WAC

173

- 205

- 060(3)(a)

.

J. Groundwater q uality l imits

The groundwater quality s tandards (c hapter 173

- 200 WAC) protect beneficial uses of groundwater . Permits issued by Ecology must not allow vio lations of those standards (WAC 173

- 200

- 100).

The Redondo WWTP does not discharge wastewater to the ground

. N o permit limits are required to protect groundwater

.

K. Comparison of e ffluent l imits w ith t he p revious permit modified on November 1, 2008

The proposed effluent limits are the same as the previous limits.Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 27 of 73

Table 14 . Comparison of Previous and Proposed Effluent Limits

Previous Effluent Limits:

Outfall No. 001 Proposed Effluent Limits:

Outfall No. 001

Parameter Basis of

Limit Average

Monthly Average

Weekly Average

Monthly Average

Weekly

CBOD 5 Technology 25 mg/L 1168 lbs/day

85% removal 40 mg/L

1868 lbs/day 25 mg/L

1168 lbs/day

85% removal 40 mg/L

1868 lbs/day

TSS Technology 30 mg/L

1401 lbs/day

85% removal 45 mg/L

2102 lbs/day 30 mg/L

1401 lbs/day

85% removal 45 mg/L

2102 lbs/day

Parameter Monthly
Geometric

Mean Limit Weekly

Geometric

Mean Limit Monthly

Geometric

Mean Limit Weekly

Geometric

Mean Limit

Fecal Coliform

Bacteria Technology 200/100 mL 400/100 mL 200/100 mL 400/100 mL

Parameter Limit Limit

pH Technology 6.0

- 9.0 6.0

- 9.0

Parameter Average Monthly Maximum

Daily Average

Monthly Maximum

Daily

Total Residual
Chlorine WQ 1 20 μg/L 312 μg/L 1 20 μg/L 312 μg/L



### IV. Monitoring Requirements

Ecology requires m onitoring, recording, and reporting (WAC 173

- 220

- 210 and 40 CFR 122.41) to verify that the treatment process is functioning correctly and that the discharge complies with the permit’s effluent limits

. If a facility uses a contract laboratory to monitor wastewater, it must ensure that the laboratory uses the methods and meets or exceeds the method detection levels required by the permit. The permit describes when facilities may use alternative methods. It also descr ibes what to do in certain situations when the laboratory encounters matrix effects. When a facility uses an alternative method as allowed by the permit, it must report the test method, DL, and QL on the discharge monitoring report or in the required repo rt.

A. Wastewater m onitoring

The monitoring schedule is detailed in the proposed permit under Special Condition S.2. Specified monitoring frequencies take into account the quantity and variability of the discharge, the treatment method, past compliance, significance of pollutants, and cost of monitoring. The required monitoring frequency is consistent w ith agency guidance given in the current version of Ecology’s Permit Writer's Manual (Publication Number 92

- 09) for trickling filter facilities > 2.0 MGD

.Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 28 of 73

Ecology has included some additional monitoring of nutrients in the proposed permit to

establish a baseline for this discharger. It will use this data in the future as it develops TMDLs for dissolved oxygen and establishes WLAs for nutrients.

Monitoring of sludge quantity and quality is necessary to determine the appropriate uses of the sludge. Bios olids monitoring is required by the current state and local solid waste management program and also by EPA under 40 CFR 503.

B

. Lab accreditation

Ecology requires that facilities must use a laboratory registered or accredited under the provisions of chapter 173

- 50 WAC, Accreditation of Environmental Laboratories

, to prepare all monitoring data (with the exception of certain parameters). Applicable monitoring data for Redondo WWTP will be prepared by the laboratory at the District’s Lakota facility. It should be noted that the Redondo WWTP staff perform analysis of pH and DO. Ecology accredited the laboratory at th e Lakota facility for BOD 5 /CBOD 5 , chl orine (residual), DO, pH, TSS, t urbidity, and fecal coliform. The lab accreditation number is M 674

.

Table 15 . Accredited Parameters

General Chemistry

P arameter name A nalyte code M ethod description NELAC code M atrix *

Turbidity 2055 SM 2130 B

- 01 20048219 N

Solids, Total Suspended 1960 SM 2540 D

- 97 20051201 N

Chlorine (Residual), Total 1940 SM 4500

- Cl G

- 00 20081612 N

pH 1900 SM 4500

- H+ B

- 00 20105219 N

Dissolved Oxygen 1880 SM 4500

- O G

- 01 20121408 N

Biochemical Oxygen Demand 1530 SM 5210 B

- 01 20135006 N

Solids, Total, Fixed and Volatile 1725 SM 2540 G

- 97 WM920420 S

Microbiology

P arameter name A nalyte code M ethod description NELAC code M atrix *

Fecal coliform

- count 2530 SM 9222 D (m

- FC)

- 97 20210008 N

* Matrix key: N = non

- potable water; S = solids and chem ical materials



### V. Other Permit Conditions

A. R eporting and record keeping

Ecology base d Special C ondition S3 on its authority to specify any appropriate reporting and

record keeping requirements to prevent and control waste discharges (WAC 173

- 220

- 210).Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 29 of 73

B. Prevention of facility overloading

Overloading of the treatment plant is a violation of the terms and conditions of the permit. To prevent this from occurring, RCW 90.48.110 and WAC 173

- 220

- 150 require Redondo

WWTP to:

• Take the actions detailed in proposed permit Special C ondition S.4.

• Des ign and construct expansions or modifications before the treatment plant reaches existing capacity.

• Report and correct conditions that could result in new or increased discharges of pollutants.

Special Condition S.4 restricts the amount of flow.

If a municipality intends to apply for Ecology

- administered funding for the design or construction of a facility project, the plan must meet the standard of a “Facility Plan”, as defined

in WAC 173

- 98

- 030. A complete “Facility Plan” includes all elements of an “Engineering Report” along with State Environmental Review Process (SERP) documentation to demonstrate compliance with 40 CFR 35.3140 and 40 CFR 35.3145, and a cost effectiveness analysis as required by WAC 173

- 98

- 730. The municipality should contact Ecolo gy’s regional office as early as practical before planning a project that may include Ecology

- administered funding.

C. Operation and maint enance

The proposed permit contains Special Condition S.5 as authorized under R CW 90.48.110,

WAC 173

- 220

- 150, c hapter 173

- 230 WAC, and WAC 173

- 240

- 080. Ecology included it to ensure proper operation and regular maintenance of equipment, and to ensure that Redondo

WWTP takes adequate safeguards so that it uses constructed facilities to their optimum potential in terms of pollutant capture and treatment.

Significant portions of the collection system are 35 y ears old, were constructed using techniques such as concrete pipes with oakum packing and/or have numerous manholes

, which were not installed us ing modern materials. Ecology expects leaks are present in the collection system due to its age, materials used

, and, construction methods for its installation. Therefore, t he proposed permit require s the Redondo WWTP to characterize the collection

syste m for the presence of leaks by providing the following information :

• Volume of the annual average and peak daily flow under worst conditions (inflow or infiltration) attributed to leaks

.

• Location of each individual leaks

.

• Size of each leak and/ or volume of excess flow contributed by a run of sewer

.

• Whether exfiltration occurs in the system’s force mains and/or inverted siphons

. Three good references to aid in these tasks include :

• American Society of Civil Engineers and Water Environment Feder ation Manual of

Practice FD

- 6, Existing Sewer Evaluation and Rehabilitation

.

• U.S. Environmental Protection Agency, Handbook for Sewer System Infrastructure Analysis and Rehabilitation

, EPA/625/6

- 91/030 , 1991.Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 30 of 73

• Washington Sta te Department of Transportation, Standard Specifications for Road, Bridge, and Municipal Construction

, 2002.

Following characterization of the leaks, Ecology may require corrective actions by issuing an administrative order following review of the assessment.

D. Pretreatment

Duty to enforce discha rge prohibitions

This provision prohibits the publicly owned treatment works ( POTW ) from authorizing or permitting an industrial discharger to discharge certain types of waste into the sanitary sewer.

• The first section of the pretreatment requirements pr ohibits the POTW from accepting pollutants which causes “ pass

- through” or “interference .” This general prohibition is from 40 CFR §403.5(a). Appendix C of this fact sheet defines these terms.

• The second section reinforces a number of specific state and f ederal pretreatment prohibitions found in WAC 173

- 216

- 060 and 40 CFR §403.5(b). These reinforce that the POTW may not accept certain wastes, which:

a. Are prohibited due to dangerous waste rules.

b. Are explosive or flammable.

c. Have too high or low of a pH (too corrosive, acidic or basic).

d. May cause a blockage such as grease, sand, rocks, or viscous materials.

e. Are hot enough to cause a problem.

f. Are of sufficient strength or volume to interfere with treatment.

g. Contain too much petroleum

- based oils, mineral oil, or cutting fluid.

h. Create noxious or toxic gases at any point.

40 CFR Part 403 contains the regulatory basis for these prohibitions, with the exception of the pH provisions which are based on WAC 173

- 216

- 060.

• The third section of pretreatment conditions reflects state prohibitions on the POTW accepting certain types of discharges unless the discharge has received prior written authorization from Ecology. These discharges include:

a. Cooling water in signif icant volumes.

b. Stormwater and other direct inflow sources.

c. Wastewaters significantly affecting system hydraulic loading, which do not require

treatment.

Federal and state pretreatment program requirements

Ecology administers the Pretreatment Program unde r the terms of the addendum to the “Memorandum of Understanding between Washington Department of Ecology and the United States Environmental Protection Agency, Region 10” (1986) and 40 CFR, part 403. Under this delegation of authority, Ecology issues wast ewater discharge permits for significant industrial users (SIUs) discharging to POTWs which have not been delegated authority to issue wastewater dischargeFact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 31 of 73

permits. Ecology must approve, condition, or deny new discharges or a significant increase in the

d ischarge for existing signif icant industrial users (SIUs) [ 40 CFR 403.8 (f) (1)(i) and(iii)]

. Industrial dischargers must obtain a permit from Ecology before discharging waste to the

Redondo WWTP [ WAC 173

- 216

- 110(5) ] . Industries discharging wastewater that is similar in character to domestic wastewater do not require a permit.

Routine identification and reporting of industrial users

The permit requires non

- delegated POTWs to take “continuous, routine measures to identify all existing, new, and proposed sign ificant industrial users (SIUs) and potential significant industrial users (PSIUs)” discharging to their sewer system. Examples of such routine measures include regular review of water and sewer billing records, business license and building permit applic ations, advertisements, and personal reconnaissance. System maintenance personnel should be trained on what to look for so they can identify and report new industrial dischargers in the course of performing their jobs. The POTW may not allow SIUs to disc harge prior to receiving a permit, and must notify all industrial dischargers (significant or not) in writing of their responsibility to apply for a State Waste Discharge Permit. The POTW must send a copy of this notification to Ecology.

E. Solid waste s

To prevent water quality problems the facility is required in permit Special Condition S7 to store and handle all residual solids (grit, screenings, scum, sludge, and other solid waste) in accordance with the req uirements of RCW 90.48.080 and state water q uality s tandards.

The final use and disposal of sewage sludge from this facility is regulated by U.S. EPA under

40 CFR 503, and by Ecology under chapter 70.95J RCW, c hapter 173

- 308 W AC “Biosolids Management,” and c hapter 173

- 350 WAC “Solid Waste Handling S tandards .” The disposal

of other solid waste is under the jurisdiction of the King County Health Department.

Requirements for monitoring sewage sludge and record keeping are included in this permit. Ecology will use t his information , required under 40 CF R 503

, to develop or update local limits.

F

. G eneral c onditions

Ecology bases the standardized G eneral Conditions on state and federal law and regulations

. They are included in all individual domestic wastewater NPDES permits issued by Ecology

.



### VI. Permit Issuance Procedures

A. P ermit m odifications

Ecology may modify this permit to impose numerical limit s , if necessary to comply with water quality standards for s urface waters, with s ediment q uality s tandards, or with water quality

standards for groundwater s, based on new information from sources such as inspections, effluent monitoring, outfall studies, and effluent mixing studies.

Ecology may also modify this permit to comply with new or amended state or federal regulations.Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 32 of 73

B. Proposed permit issuance

Thi s proposed permit meets all statutory requirements for Ecology to authorize a wastewater discharge

. The permit includes limit s and conditions to protect human health and aquatic life, and the be neficial uses of waters of the s tate of Washington. Ecology proposes to issue

this permit for a term of 5 years.



### VII. References f or Text a nd Appendices

Environmental Protection Agency (EPA)

1992. National Toxics Rule. Federal Register, V. 57, No. 246, Tuesday, December 22, 1992.

1991. Technical Support Document for Water Quality

- based Toxics Control . EPA/505/2

- 90

- 001.

1988. Technical Guidance on Supplementary Stream Design Conditions for Steady State Modeling . USEPA Office of Water, Washington, D.C.

1985. Water Quality Assessment: A Screening Procedure for Toxic and Conventional Pollutants in Surface and Ground Water . EPA/600/6

- 85/002a.

1983. Water Quality Standards Handbook . USEPA Office of Water, Washington, D.C.

Tsivoglou, E.C., and J.R. Wallace.

1972. Characterization of Stream Reaeration Capacity . EPA

- R3

- 72

- 012 . (Cited in EPA 1985 op.cit.)

Washington State Department of Ecology.

December 2011

. Permit Writer’s Manual . Publication Number 92

- 109 ( https://fortress.wa.gov/ecy/publications/SummaryPages /92109.html )

Laws and Regulations ( http://www.ecy.wa.gov/laws

- rules/index.html )

Permit and Wastewater Related Information ( http: //www.ecy.wa.gov/programs/wq/permits/guidance.html )

Water Pollution Control Federation.

1976. Chlorination of Wastewater

. Wright, R.M., and A.J. McDonnell.

1979. In

- stream Deoxygenation Rate Prediction . Journal Environmental Engineering Division, ASCE. 105(EE2). (Cited in EPA 1985 op.cit.)Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 33 of 73



### Appendix A

-- Public Involvement Information

Ecology proposes to reissue a permit to Redondo WWTP . The permit includes wastewater discharge limit s and other cond itions . This fact sheet describes the facility and Ecology’s reasons for requiring permit conditions

. Ecology place d a Public Notice of Draft on July 22, 2013

, in the Seattle Times to inform the public and to invite comment on the proposed draft National Pollutant Discharge Elimination System permit a nd fact sheet

.
The n otice:

• T old where copies of the draft permit and fact s heet we re available for public evaluation (a

loc al public library, the closest regional or field office, posted on our websi te ).

• O ffer ed to provide the documents in an alternate format to accommodate special needs.

• A sk ed people to tell us how well the proposed permit would protect the receiving water.

• I nvite d people to suggest fairer conditions, limits, and requirements for the permit.

• I nvite d comments on Ecology’s determination of compliance with antidegradation rules.

• U rge d people to submit their comments, in writing, before the end of the comment p eriod

.

• T old how to request a public hearing a bout the proposed NPDES p ermit.

• E xplain ed the next step(s) in the permitting process.

Ecology has published a document entitled Frequently Asked Questions about Effective Public Commenting

, which is available on our website at
https://fortress.wa.gov/ecy/publications/SummaryPages /0307023.html

. You may obtain f

urther inform ation from Ecology by telephone, 425

- 649

- 7000 or by writing to

the address listed below

. Water Quality Permit Coordinator Department of Ecology

Northwest Regional Office

3190 160th Avenue SE Bellevue, WA 98008

- 5452

During the above

- noted public comment period, no comments were received.

The primary author of t his permit and fact sheet is Kevin Leung

.Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 34 of 73



### Appendix B

-- Your Right to Appeal

You have a right to appeal this permit to the Pollution Control Hearing Board (PCHB) within 30 days of the date of receipt of the final permit. The appeal process is governed by c hapter 43.21B

RCW and c hapter 371

- 08 WAC. “Date of receipt” is defined in R CW 43.21B.001(2) (see glossary)

. To appeal you must do the following within 30 days of the date of receipt of this permit :

 File your appeal and a copy of this permit with the PCHB (see addresses below). Filing means actual receipt by the PCHB during regul ar business hours.

 Serve a copy of your appeal and this permit on Ecology in paper form

- by mail or in person. (See addresses below.) E

- mail is not accepted.

You must also comply with other applicable requirements in c hapter 43.21B RCW and c hapter

371

- 08 WAC.

ADDRESS AND LOCATION INFORMATION

. Street Addresses Mailing Addresses

Department of Ecology Attn: Appeals Processing Desk
300 Desmond Drive SE Lacey, WA 98503 Department of Ecology Attn: Appeals Processing Desk
PO Box 47608 Olympia, WA 98504

- 7608

Pollution Control Hearings Board
1111 Israel RD SW

, STE 301 Tumwater, WA 98501 Pollution Control Hearings Board
PO Box 40903 Olympia, WA 98504

- 0903Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 35 of 73



### Appendix C

-- Glossary

1

- DMax or 1

- day maximum temperature

-- The highest water temperature reached on any given day. This measure can be obtained using calibrated maximum/minimum thermometers or continuous monitoring probes having sampling intervals of thirty minutes or less.

7

- DADMax or 7

- day average of the daily maximum temperatures

-- The arithmetic average of seven consecutive measures of daily maximum temperatures. The 7

- DADMax for any individual day is calculated by averaging that day's daily maximum temperature with the daily maximum temperatures of the three days prior and the three days after that date.

Acute toxicity

-- The lethal effect of a compound on an organism that occurs in a short time period, usually 48 to 96 hours.

AKART

-- The acronym for “all known, available, and reasonable methods of prevention, control and treatment.” AKART is a technology

- based approach to limiting pollutants from wastewater discharges, which requires an engineering judgment and an economic judgmen t. AKART must be applied to all wastes and contaminants prior to entry into waters of the state in accordance with RCW 90.48.010 and 520, WAC 173

- 200

- 030(2)(c)(ii), and WAC 173

- 216

- 110(1)(a).

Alternate point of compliance

-- An alternative location in the groundwater from the point of compliance where compliance with the groundwater standards is measured. It may be

established in the groundwater at locations some distance from the discharge source, up to, but not exceeding the property boundary and is dete rmined on a site specific basis following an AKART analysis. An “early warning value” must be used when an alternate point is established. An alternate point of compliance must be determined and approved in

accordance with WAC 173

- 200

- 060(2).

Ambient water quality

-- The existing environmental condition of the water in a receiving water body.

Ammonia

-- Ammonia is produced by the breakdown of nitrogenous materials in wastewater. Ammonia is toxic to aquatic organisms, exerts an oxygen demand, and contribute s to eutrophication. It also increases the amount of chlorine needed to disinfect wastewater.

Annual average design flow (AADF )

– The average of the daily flow volumes anticipated to occur over a calendar year.

Average monthly (intermittent) discharge l imit

-- The average of the measured values obtained over a calendar months time taking into account zero discharge days.

Average monthly discharge limit

-- The average of the measured values obtained over a

calendar month's time.

Background water quality

-- The concentrations of chemical, physical, biological or radiological

constituents or other characteristics in or of groundwater at a particular point in time upgradient of an activity that has not been affected by that activity [WAC 173

- 200

- 020(3)]. Bac kground water quality for any parameter is statistically defined as the 95% upper tolerance interval with a 95% confidence based on at least eight hydraulically upgradient water quality samples. The eight samples are collected over a period of at least on e year, with no more than one sample collected during any month in a single calendar year.Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 36 of 73

Best management practices (BMPs)

-- Schedules of activities, prohibitions of practices, maintenance procedures, and other physical, structural and/or managerial prac tices to prevent or reduce the pollution of waters of the state. BMPs include treatment systems, operating procedures, and practices to control: plant site runoff, spillage or leaks, sludge or waste disposal, or drainage from raw material storage. BMPs may be further categorized as operational, source control, erosion and sediment control, and treatment BMPs.

BOD5

-- Determining the five

- day Biochemical Oxygen Demand of an effluent is an indirect way of measuring the quantity of organic material present in an effluent that is utilized by bacteria. The BOD5 is used in modeling to measure the reduction of dissolved oxygen in receiving waters after effluent is discharged. Stress caused by reduced dissolved oxygen levels makes organisms less competitive and less able to sustain their species in the aquatic environment. Although BOD 5 is not a specific compound, it is defined as a conventional pollutant under the federal Clean Water Act.

Bypass

-- The intentional diversion of waste streams from any portion of a treatment facility.

Categorical pretreatment standards

-- National pretreatment standards specifying quantities or concentrations of pollutants or pollutant properties, which may be discharged to a POTW by existing or new industrial users in specific in dustrial subcategories.

Chlorine

-- A chemical used to disinfect wastewaters of pathogens harmful to human health. It is also extremely toxic to aquatic life.

Chronic toxicity

-- The effect of a compound on an organism over a relatively long time, often

1 /10 of an organism's lifespan or more. Chronic toxicity can measure survival, reproduction or growth rates, or other parameters to measure the toxic effects of a compound or combination of compounds.

Clean water act (CWA )

-- The f ederal Water Pollution Control Act enacted by Public Law

92

- 500, as amended by Public Laws 95

- 217, 95

- 576, 96

- 483, 97

- 117; USC 1251 et seq.

Compliance inspection

- without sampling

-- A site visit for the purpose of determining the compliance of a facility with the terms and condi tions of its permit or with applicable statutes and regulations.

Compliance inspection

- with sampling

-- A site visit for the purpose of determining the compliance of a facility with the terms and conditions of its permit or with applicable statutes and reg ulations. In addition it includes as a minimum, sampling and analysis for all parameters with limits in the permit to ascertain compliance with those limits; and, for municipal facilities, sampling of influent to ascertain compliance with the 85 percent r emoval requirement. Ecology may conduct additional sampling.

Composite sample

-- A mixture of grab samples collected at the same sampling point at different times, formed either by continuous sampling or by mixing discrete samples. May

be "time

- composite " (collected at constant time intervals) or "flow

- proportional" (collected either as a constant sample volume at time intervals proportional to stream flow, or collected by increasing the volume of each aliquot as the flow increased while maintaining a con stant time interval between the aliquots).Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 37 of 73

Construction activity

-- Clearing, grading, excavation, and any other activity, which disturbs the surface of the land. Such activities may include road building; construction of residential houses, office buildi ngs, or industrial buildings; and demolition activity.

Continuous monitoring

-- Uninterrupted, unless otherwise noted in the permit.

Critical condition

-- The time during which the combination of receiving water and waste discharge conditions have the high est potential for causing toxicity in the receiving water environment. This situation usually occurs when the flow within a water body is low, thus, its ability to dilute effluent is reduced.

Date of receipt

– This is defined in RCW 43.21B.001(2) as five business days after the date of mailing; or the date of actual receipt, when the actual receipt date can be proven by a preponderance of the evidence. The recipient's sworn affidavit or declaration indicating the date of receipt, which is unchallenged by t he agency, constitutes sufficient evidence of actual receipt. The date of actual receipt, however, may not exceed forty

- five days from the date of mailing.

Detection limit

– see Method Detection Level

. Dilution factor (DF)

-- A measure of the amount of mix ing of effluent and receiving water that occurs at the boundary of the mixing zone. Expressed as the inverse of the percent effluent fraction, for example, a dilution factor of 10 means the effluent comprises 10% by volume and the receiving water 90%.

Dis tribution uniformity

-- The uniformity of infiltration (or application in the case of sprinkle or trickle irrigation) throughout the field expressed as a percent relating to the average depth

infiltrated in the lowest one

- quarter of the area to the average depth of water infiltrated.

Early warning value

-- The concentration of a pollutant set in accordance with WAC

173

- 200

- 070 that is a percentage of an enforcement limit. It may be established in the effluent, groundwater , surface water, the vadose zone or within the treatment process. This value acts as a trigger to detect and respond to increasing contaminant concentrations prior to the degradation of a beneficial use.

Enforcement limit

-- The concentration assigned to a contaminant in the groundwater at t he point of compliance for the purpose of regulation, [WAC 173

- 200

- 020(11)]. This limit

assures that a groundwater criterion will not be exceeded and that background water quality will be protected.

Engineering report

-- A document that thoroughly examines the engineering and administrative aspects of a particular domestic or industrial wastewater facility. The report must contain the appropriate information required in WAC 173

- 240

- 060 or 173

- 240

- 130.

Fecal coliform bacteria

-- Fecal coliform bacteria are used as indicators of pathogenic bacteria in the effluent that are harmful to humans. Pathogenic bacteria in wastewater discharges are controlled by disinfecting the wastewater. The presence of high numbers of fecal coliform bacteria in a water body can indicate the recent release of untreated wastewater and/or the presence of animal feces.

Grab sample

-- A single sample or measurement taken at a specific time or over as short a period of time as is feasible.Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 38 of 73

Groundwater

-- Water in a saturated zone or st ratum beneath the surface of land or below a surface water body.

Industrial user

-- A discharger of wastewater to the sanitary sewer that is not sanitary wastewater or is not equivalent to sanitary wastewater in character.

Industrial wastewater

-- Water or liquid

- carried waste from industrial or commercial processes, as distinct from domestic wastewater. These wastes may result from any process or activity of industry, manufacture, trade or business; from the development of any natural resource; or

from an imal operations such as feed lots, poultry houses, or dairies. The term includes contaminated storm water and, also, leachate from solid waste facilities.

Interference

-- A discharge which, alone or in conjunction with a discharge or discharges from

other sources, both:

 Inhibits or disrupts the POTW, its treatment processes or operations, or its sludge processes, use or disposal; and

 Therefore is a cause of a violation of any requirement of the POTW's NPDES permit (including an increase in the magnitude or duration of a violation) or of the prevention of sewage sludge use or disposal in compliance with the following statutory provisions and regulations or permits issued thereunder (or more stringent State or local regulations):

Section 405 of the Clean Wate r Act, the Solid Waste Disposal Act (SWDA) (including title II, more commonly referred to as the Resource Conservation and Recovery Act (RCRA), and including State regulations contained in any State sludge management plan prepared pursuant to subtitle D of the SWDA), sludge regulations appearing in 40 CFR Part 507, the Clean Air Act, the Toxic Substances Control Act, and the Marine Protection, Research and Sanctuaries Act.

Local limits

-- Specific prohibitions or limits on pollutants or pollutant parameters developed by

a POTW.

Major facility

-- A facility discharging to surface water with an EPA rating score of > 80 points based on such factors as flow volume, toxic pollutant potential, and public health impact.

Maximum daily discharge limit

-- The highest allowable daily discharge of a pollutant measured during a calendar day or any 24

- hour period that reasonably represents the calendar day for purposes of sampling. The daily discharge is calculated as the average measurement of the pollutant over the day

. Maximum day design flow (MDDF )

-- The largest volume of flow anticipated to occur during a

one

- day period, expressed as a daily average.

Maximum month design flow (MMDF)

-- The largest volume of flow anticipated to occur during a continuous 30

- day per iod, expressed as a daily average.

Maximum week design flow (MWDF )

-- The largest volume of flow anticipated to occur during a continuous 7

- day period, expressed as a daily average.

Method detection level (MDL)

-- The minimum concentration of a substance that can be measured and reported with 99 percent confidence that the pollutant concentration is above zero and is determined from analysis of a sample in a given matrix containing the pollutant.Fact Sheet for NPDES Permit No.WA 0023451

Redondo Wastewater Treatment Plant Page 39 of 73

Minor facility

-- A facility discharging to surface water wi th an EPA rating score of < 80 points based on such factors as flow volume, toxic pollutant potential, and public health impact.

Mixing zone

-- An area that surrounds an effluent discharge within which water quality criteria may be exceeded. The permit specifies the area of the authorized mixing zone that Ecology defines following procedures outlined in state regulations (chapter 173

- 201A WAC ).

National pollutant discharge elimination system (NPDES)

-- The NPDES (Section 402 of the Clean Water Act) is the federal wastewater permitting system for discharges to navigable waters of the United States. Many states, including the state of Washingto n, have been delegated the authority to issue these permits. NPDES permits issued by Washington State permit writers are joint NPDES/State permits issued under both state and federal laws.

pH

-- The pH of a liquid measures its acidity or alkalinity. It is the negative logarithm of the hydrogen ion concentration. A pH of 7 is defined as neutral and large variations above or below this value are considered harmful to most aquatic life.

Pass

- through

-- A discharge which exits the POTW into waters of the St ate in quantities or concentrations which, alone or in conjunction with a discharge or discharges from other sources, is a cause of a violation of any requirement of the POTW's NPDES permit (including an increase in the magnitude or duration of a violation ), or which is a cause of a violation of State water quality standards.

Peak hour design flow (PHDF)

-- The largest volume of flow anticipated to occur during a

one

- hour period, expressed as a daily or hourly average.

Peak instantaneous design flow (PIDF)

-- The maximum anticipated instantaneous flow.

Point of compliance

-- The location in the groundwater where the enforcement limit must not be exceeded and a facility must comply with the Ground Water Quality Standards. Ecology

determines this limit on a s ite

- specific basis. Ecology locates the point of compliance in the groundwater as near and directly downgradient from the pollutant source as technically, hydrogeologically, and geographically feasible, unless it approves an alternative point of compliance

. Potential significant industrial user (PSIU)

-- A potential significant industrial user is defined as an Industrial User that does not meet the criteria for a Significant Industrial User, but which discharges wastewater meeting one or more of the followin g criteria:

a. Exceeds 0.5 % of treatment plant design capacity criteria and discharges <25,000 gallons per day ; or

b. Is a member of a group of similar industrial users which, taken together, have the potential to cause pass through or interference at the POTW (e.g. facilities which develop photographic film or paper, and car washes).

Ecology may determine that a discharger initially classified as a potential significant industrial user should be managed as a significant industrial user.

Quantitation level (QL)

-- Also known as Minimum Level of Quantitation (ML)

– The lowest level at which the entire analytical system must give a recognizable signal and acceptable calibration point for the analyte. It is equivalent to the concentration of the lowest calibr ation standard, assuming that the lab has used all method

- specified sample weights, volumes, andFact Sheet for NPDES Permit No.WA 0023451

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cleanup procedures. The QL is calculated by multiplying the MDL by 3.18 and rounding the result to the number nearest to (1, 2, or 5) x 10 n , where n is an inte ger (64 FR 30417).

ALSO GIVEN AS: The smallest detectable concentration of analyte greater than the Detection Limit (DL) where the accuracy (precision & bias) achieves the objectives of the intended purpose. ( Report of the Federal Advisory Committee on D etection and Quantitation Approaches and Uses in Clean Water Act Programs Submitted to the US Environmental Protection Agency

, December 2007).

Reasonable potential

-- A reasonable potential to cause a water quality violation, or loss of

sensitive and/or im portant habitat.

Responsible corporate officer

-- A president, secretary, treasurer, or vice

- president of the corporation in charge of a principal business function, or any other person who performs similar policy

- or decision

- making functions for the corp oration, or the manager of one or more manufacturing, production, or operating facilities employing more than 250 persons or have gross annual sales or expenditures exceeding $25 million (in second quarter 1980 dollars), if authority to sign documents has been assigned or delegated to the manager in accordance with corporate procedures (40 CFR 122.22).

Significant industrial user (SIU)

-- 1) All industrial users subject to Categorical Pretreatment Standards under 40 CFR 403.6 and 40 CFR Chapter I, Subchapte r N ; and

2) Any other industrial user that: discharges an average of 25,000 gallons per day or more of process wastewater to the POTW (excluding sanitary, noncontact cooling, and boiler

blow

- down wastewater); contributes a process wastestream that makes up 5 percent or more of the average dry weather hydraulic or organic capacity of the POTW treatment plant; or is designated as such by the Control Authority* on the basis that the industrial user has a reasonable potential for adversely affecting the POTW 's operation or for violating any pretreatment standard or requirement [ in accordance with 40 CFR 403.8(f)(6) ]

. Upon finding that the industrial user meeting the criteria in paragraph 2, above, has no reasonable potential for adversely affecting the POTW's operation or for violating any pretreatment standard or requirement, the Control Authority* may at any time, on its own initiative or in response to a petition received from an industrial user or POTW, and in accordance with 40 CFR 403.8(f)(6), determine that such industrial user is not a significant

industrial user.

*The term "Control Authority" refers to the Washington State Department of Ecology in the

case of non

- delegated POTWs or to the POTW in the case of delegated POTWs.

Slug discharge

-- Any disch arge of a non

- routine, episodic nature, including but not limited to an accidental spill or a non

- customary batch discharge to the POTW. This may include any pollutant released at a flow rate that may cause interference or pass through with the POTW

or in any way violate the permit conditions or the POTW’s regulations and local limits

.
Soil scientist

-- An individual who is registered as a Certified or Registered Professional Soil Scientist or as a Certified Professional Soil Specialist by the American Reg istry of CertifiedFact Sheet for NPDES Permit No.WA 0023451

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Professionals in Agronomy, Crops, and Soils or by the National Society of Consulting Scientists or who has the credentials for membership. Minimum requirements for eligibility are: possession of a baccalaureate, masters, or doctorate de gree from a U.S. or Canadian institution with a minimum of 30 semester hours or 45 quarter hours professional core courses in agronomy, crops or soils, and have 5, 3, or 1 year ( s ) , respectively, of professional experience working in the area of agronomy, c rops, or soils.

Solid waste

-- All putrescible and non

- putrescible solid and semisolid wastes including, but not limited to, garbage, rubbish, ashes, industrial wastes, swill, sewage sludge, demolition and construction wastes, abandoned vehicles or parts thereof, contaminated soils and contaminated dredged material, and recyclable materials.

Soluble BOD 5 -- Determining the soluble fraction of Biochemical Oxygen Demand of an effluent is an indirect way of measuring the quantity of soluble organic material present in an

effluent that i s utilized by bacteria. Although the soluble BOD 5 test is not specifically described in Standard Methods, filtering the raw sample through at least a 1.2 um filter prior to running the standard BOD 5 test is sufficient to remove the particulate organic frac tion.

State waters

-- Lakes, rivers, ponds, streams, inland waters, underground waters, salt waters, and all other surface waters and watercourses within the jurisdiction of the state of Washington.

Stormwater

-- That portion of precipitation that does not naturally percolate into the ground or evaporate, but flows via overland flow, interflow, pipes, and other features of a storm water drainage system into a defined surface water body, or a constructed infiltration facility.

Technology

- based effluent limit

-- A permit limit based on the ability of a treatment method to reduce the pollutant.

Total coliform bacteria

-- A microbiological test, which detects and enumerates the total coliform group of bacteria in water samples.

Total dissolved solids

-- That por tion of total solids in water or wastewater that passes through a specific filter.

Total maximum daily load (TMDL)

-- A determination of the amount of pollutant that a water body can receive and still meet water quality standards.

Total suspended solids (T SS)

-- Total suspended solids is the particulate material in an effluent. Large quantities of TSS discharged to a receiving water may result in solids accumulation. Apart from any toxic effects attributable to substances leached out by water, suspended solids may kill fish, shellfish, and other aquatic organisms by causing abrasive injuries and by clogging the gills and respiratory passages of various aquatic fauna. Indirectly, suspended solids can screen out light and can promo te and maintain the development of noxious conditions through oxygen depletion.

Upset

-- An exceptional incident in which there is unintentional and temporary noncompliance with technology

- based permit effluent limits because of factors beyond the reason able control of the Permittee. An upset does not include noncompliance to the extent caused by operational error, improperly designed treatment facilities, lack of preventative maintenance, or careless or improper operation.Fact Sheet for NPDES Permit No.WA 0023451

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Water quality

- based effluent l imit

-- A limit imposed on the concentration of an effluent parameter to prevent the concentration of that parameter from exceeding its water quality criterion after discharge into receiving waters.Fact Sheet for NPDES Permit No.WA 0023451

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### Appendix D

-- Technical Calculations

Several of the Exc el® spreadsheet tools used to evaluate a discharger’s ability to meet Washington State water quality standards can be found on Ecology ’s homepage at http://www.ecy.wa.gov/programs/wq/per mits/guidance.html

. Simple Mixing :

Ecology uses simple mixing calculations to assess the impacts of certain conservative pollutants, such as the expected increase in fecal coliform bacteria at the edge of the chronic mixing zone boundary. Simple mixing use s a mass balance approach to proportionally distribute a pollutant load from a discharge into the authorized mixing zone. The approach assumes no decay or generation of the pollutant of concern within the mixing zone. The predicted concentration at the edg e of a mixing zone (MC) is based on the following calculation:

MC = [ EC + (AC X DF)]/(1 + DF)

where:

EC = Effluent Concentration

AC = Ambient Concentration

DF = Dilution Factor

Reasonable Potential Analysis:

The spreadsheets in Ecology’s PermitCalc Workbook determine reasonable potential (to violate the aquatic life water quality standards) and calculate effluent limits, determine reasonable potential and calculate effluent limits for human health pollutants. The process and formulas for

d etermining reasonable potential and effluent limits in these spreadsheets are taken directly from

the Technical Support Document for Water Quality

- based Toxics Control , (EPA 505/2

- 90

- 001). The adjustment for autocorrelation is from EPA (1996a), and EPA (19 96b).

Calculation of Water Quality

- Based Effluent Limits:

Water quality

- based effluent limits are calculated by the two

- value wasteload allocation process as described on page 100 of the TSD (EPA, 1991) and shown below.

1. Calculate the acute wasteload alloc ation WLA

a by multiplying the acute criteria by the acute dilution factor and subtracting the background factor. Calculate the chronic wasteload allocation (WLA

c ) by multiplying the chronic criteria by the chronic dilution factor and subtracting the backgr ound factor.

WLA

a = (acute criteria x DF
a )

– [ (b ac kgr ou nd conc.x ( DF
a - 1)]

WLA

c = (chronic criteria x DF
c )

– [ (b ac kgr ou nd conc. x ( DF
c - 1) ]

where: DF
a = Acute Dilution Factor

DF
c = Chronic Dilution FactorFact Sheet for NPDES Permit No.WA 0023451

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2. Calculate the long term averages (LTA

a and LTA

c ) which will comply with the wasteload

allocations WLA

a and WLA

c .

LTA

a = WLA

a  e [0.5  2

- z  ] where:  2 = ln[CV2 + 1]

z = 2.326

CV = coefficient of variation = std. dev./mean

LTA

c = WLA

c  e [0.5  2

- z  ] where:  2 = ln[(CV2  4) + 1]

z = 2.326

3. Use the smallest LTA of the LTA

a or LTA

c to calculate the maximum daily effluent limit and the monthly average effluent limit.

Maximum Daily Limit = MDL

where:  2 = ln[CV 2 + 1]

z = 2.326 (99th percentile occurrence )

LTA = Limiting long term average

Average Monthly Limit = AML

where:  2 = ln[(CV2  n) + 1]

n = number of samples/month

z = 1.645 (95 th % occurrence probability)

LTA = Limiting long term averageFact Sheet for NPDES Permit No.WA 0023451

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Redondo WWTP Process SchematicFact Sheet for NPDES Permit No.WA 0023451

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Reasonable Potential Calculation sFact Sheet for NPDES Permit No.WA 0023451

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Calculations for Fecal ColiformFact Sheet for NPDES Permit No.WA 0023451

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Calculations for AmmoniaFact Sheet for NPDES Permit No.WA 0023451

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Calculations for Temp e ratureFact Sheet for NPDES Permit No.WA 0023451

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Redondo WWTP Data (2008

- 2012)Fact Sheet for NPDES Permit No.WA 0023451

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Redondo WWTP Data (2008

- 2012)Fact Sheet for NPDES Permit No.WA 0023451

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Redondo WWTP Influent

– Flow

Redondo WWTP Effluent

– pHFact Sheet for NPDES Permit No.WA 0023451

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Redondo WWTP Influent

– TSSFact Sheet for NPDES Permit No.WA 0023451

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Redondo WWTP Influent

– BODFact Sheet for NPDES Permit No.WA 0023451

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Redondo WWTP Effluent

– TSSFact Sheet for NPDES Permit No.WA 0023451

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Redondo WWTP Effluent

– CBOD 5Fact Sheet for NPDES Permit No.WA 0023451

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Redondo WWTP Effluent

– Fecal ColiformFact Sheet for NPDES Permit No.WA 0023451

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Redondo WWTP Effluent

– Priority PollutantsFact Sheet for NPDES Permit No.WA 0023451

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Redondo WWTP Effluent

– Priority Pollutants (Continued)Fact Sheet for NPDES Permit No.WA 0023451

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Redondo WWTP Effluent

– Priority Pollutants (Continued)Fact Sheet for NPDES Permit No.WA 0023451

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Redondo WWTP Effluent

– Priority Pollutants (Continued)Fact Sheet for NPDES Permit No.WA 0023451

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Redondo WWTP Effluent

– MetalsFact Sheet for NPDES Permit No.WA 0023451

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Redondo WWTP Effluent

- Nutrient DataFact Sheet for NPDES Permit No.WA 0023451

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Redondo WWTP Effluent

- Acute NOECFact Sheet for NPDES Permit No.WA 0023451

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Redondo WWTP Effluent

- Acute %SurvivalFact Sheet for NPDES Permit No.WA 0023451

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Redondo WWTP Effluent

– Chronic NOECFact Sheet for NPDES Permit No.WA 0023451

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Mixing Calculation

– Outfall

The chronic and acute dilution factors included in the engineering re port (Lakehaven, 2005) were 364:1 and 159:1, respectively, and are included in the tables below. However, the modeling procedure did not take reflux (i.e. increases in ambient concentrations due to tidal reversals) into

consideration. In the previous per mit, this was addressed by reducing the predicted dilution factors by half to account for tidal reversals. Ecology believes this approach conservatively estimates the available dilution. Accordingly, Ecology used the chronic and acute dilution

factors of 182:1 and 79:1, respectively, in the previous permit. Ecology continues to use these dilution factors until the District revises the mixing model and engineering report to model

reflux.Fact Sheet for NPDES Permit No.WA 0023451

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Mixing Calculation

– Outfall

Acute

– Dilution R unFact Sheet for NPDES Permit No.WA 0023451

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Mixing Calculation

– Outfall

Chronic

– Dilution R unFact Sheet for NPDES Permit No.WA 0023451

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### Appendix E

-- Response t o Comments

During the public comment period, no comments were received.

On July 3, 2013, the Lakehaven Utility District submitted comments after their initial review of the draft p ermit and fact sheet, prior to the public notice of draft. The comments and Ecology’s responses are as follows:

Draft NPDES Permit (Entity Review)

Comment 1: Cover page

- The plant is a Trickling Filter, not an Activated Sludge Plant.

Response: The draft permit has been revised to include the correct treatment plant type.

Comment 2: Cover Page

- The discharge location for the outfall is incorrect and reflects the old outfall. The correct coordinates are Latitude 47.34941, Longitude

- 122.338038.

Response: The draft permit has been revised to include the correct outfall coordinates

.
Comment 3: Section S1.A, Footnote (e)

- The sentence “During normal operations with UV disinfection, chlorine limits do not apply” should be revised. It can be interpreted to mean that as long as you are using UV disinfection you may also add chlorine and not worry about chlorine limits.

Response: Ecology does not believe that changes to the footnote are necessary. The first sentence of this footnote states that chlorine limits apply only during emergency periods when UV disinfection is not available and the District uses chlorine for disinfection. During periods when UV is used for disinfection and chlorine is used for control of odors or filamentous bacteria, it is assumed that any residual chlorine will be oxidized prior to the discharge.

Comment 4:

Section S2.A.5

- lists Cyanide on two different lines, o nce as a grab, and once as a

24

- Hour composite. Clarification is needed.

Response: The line with cyanide moni toring as a grab sample has been deleted. Cyanide monitoring is still required under the priority pollutant analysis for “Metals, Cyanide, & Total

Phenols”.

Comment 5: Section S2.A., Footnote (g)

- states “3/week means three (3) times during each calendar

w eek and on a rotational basis throughout the days of the week, except weekends and holidays.” Due to the nature of the testing that involves reading the dissolved oxygen 5Fact Sheet for NPDES Permit No.WA 0023451

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days later, CBOD 5 can only be setup for analysis on Wednesday, Thursday, or Friday and avoid turning on a sampler or analyzing on weekends. Likewise to avoid analysis or turning on a sampler during a weekend, TSS can only be analyzed on Tuesday, Wednesday, Thursday, or Friday, and Fecal Coliform can only be analyzed on Monday, Tuesday, Wednesday, and Thursday limiting the ability to rotate throughout the days of the week.

Response: The footnote has been revised to “3/week means three (3) times during each calendar week.”

Comment 6:

Section S3.E.a.

- discusses the conditions that require i mmediate reporting. Lakehaven Utility District would like clarification on what is meant by “collection system overflows” and “any other failures of the sewage system (pipe breaks, etc.)”. Is there a minimum amount of liquid leaving the collection system that constitutes an overflow? If the overflow is minimal and can be cleaned up immediately without any environmental damage does it still need to be reported? During construction of a collection system quite often the organization must break into an exi sting pipe, does this need to be immediately reported under this section?

Response: The term “collection system overflows” means any overflows from the collection system including, but not limited to, sewage overflows from manholes, pump stations and other parts of the collection system due to blockages, inadequate conveyance capacity, excessive I/I, root intrusion, etc. The term “any other failures of the sewage system (pipe breaks, etc.)” means failures of the collection system including, but not limited to, gravity sewer line breaks, force main breaks, pump station power failures, etc. All collection system sewage overflows need to be reported and there is no minimum quantity of overflow that is exempt from reporting. During construction of collection sys tem improvements, Ecology expects that the District will take the necessary safeguards to prevent sewage overflows including plugging and bypass pumping. For clarification, Ecology has revised the text under immediate reporting from “Collection system over flows” to “Collection system overflows that may reach surface waters .”

Comment 7:

Section S3.E.b.

- discusses twenty

- four

- hour reporting, Lakehaven would like clarification on what is meant by “any overflow prior to the treatment works”.

Response:

Under 24 hour reporting, the term “any overflow prior to the treatment works” means any overflow that occurs prior to reaching the WWTP site (i.e. any collection system overflow) that is not covered under the immediate reporting section.

Comment 8:

Section S9.B.

- states “Following Ecology approval of the Sediment Sampling and Analysis Plan, the Permittee must collect sediments between August 15 th and September 15 th .” Lakehaven assumes that the collection occurs in 2016, but for clarification the year should be

noted.

Response: The year 2016 has been added for clarification.Fact Sheet for NPDES Permit No.WA 0023451

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Draft Fact Sheet (Entity Review)

Comment 9:

II.Table 1

- The discharge location for the outfall is incorrect and reflects the old outfall. The correct coordinates are Latitude 47.34941, Longitude

- 122.338038.

Response: The draft fact sheet has been revised to include the correct outfall coordinates

.
Comment 10: II.A.History

- The belt filter press was removed and replaced with a rotary press in 2010.

Response: The draft fact sheet has been revised to include the updated information.

Comment 11: II.A. Treatment processes

- Replace “manually cleaned bar screen” with “mechanically cleaned bar screen”. Replace “belt filter press” with “rotary press”.

Response: The draft fact sheet has been revi sed to include the correct information.

Comment 12:

II.A. Staff

- There are 5 certified operators and 1 operator

- in

- training located at the Redondo plant. There are an additional 5 certified operators in support roles that are available to work

at Redondo if necessary.

Response: The draft fact sheet has been revised to include the updated information.

Comment 13:

II.A. Staff

- The Lakota Laboratory operates from 6:30 to 3:00pm.

Response: The draft fact sheet has been revised to include the updated informati on.

Comment 14:

II.A. Solid wastes/Residual Solids

- Redondo does not transport solids wastes to Lakota, but rather disposes of them directly to a landfill.

Response: The draft fact sheet has been revised to include the correct information.

Comment 15:

II.A. Solid wastes/Residual Solids

- Replace “belt filter press” with “rotary press”.

Response: The draft fact sheet has been revised to include the correct information.

Comment 16:

II.A. Solid wastes/Residual Solids

- Dewatered sludge is not normally trucked to a beneficial reuse composting facility, the composting facility is kept as a backup site.Fact Sheet for NPDES Permit No.WA 0023451

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Normally the dewatered sludge is trucked to a beneficial reuse facility in Eastern

Wa shington for land application.

Response: The draft fact sheet has been revised to include the correct information.

Comment 17: II.E. Summary of compliance/Table 5

- The first row of data shows an Influent TSS permit violation for weekly TSS, which should be “Effluent TSS”.

Response: The draft fact sheet has been revised to include the correct information.

Comment 18: II.E. Summary of compliance/Table 5

- The third row of data shows a permit violation for a

late submittal of the December 2010 DMR. Lakehaven d oes not agree that there was a late submittal of the Redondo DMR. The Lakota and Redondo DMRs are compiled at the same time, signed at the same time, and mailed in the same envelope. The two DMRs were mailed on or about January 7, 2011, and there is no i ndication that the Lakota DMR was late.

Response: Ecology concurs with the District’s comment that there was not a late DMR submittal. Ecology has removed the late DMR submittal from the table.

Comment 19:

III.F. Evaluation of surface water

- The third par agraph discusses the diffuser at Outfall No.001. There is no diffuser on this outfall, the outfall pipe is 2,670 feet long, and there is only one port.

Response: The draft fact sheet has been revised to include the correct information

.
Comment 20:

IV.B. Lab accreditation

- The Lakota Laboratory accreditation number is M674, not M028. Redondo pH and DO are performed by Redondo staff, not in the Lakota Laboratory.

Response: The draft fact sheet has been revised to include the correct information

.