ASTORIA 

FACT SHEET 

And 

NPDES WASTEWATER DISCHARGE PERMIT EVALUATION 

Oregon Department of Environmental Quality 

Northwest Region - Portland Office 

2020 SW 4th Ave., Suite 400, Portland, OR 97201 

Telephone: (503) 229-5263 & FAX 503 229-6957 

File Number: 3924 

Permit Number: 102397 

Permit Application Number: 977031 

Permit Application Date: September 20,2006 

Permittee: 

City of Astoria 

1095 Duane Street 

Astoria, OR 97103 

Source Contact: 

Ken Cook 

Public Works Director 

Telephone Number: 503.338.5173 

Proposed Action: Renewal of a National 

Pollutant Discharge Elimination System 

(NPDES) wastewater discharge permit. 

Receiving Stream: Columbia River (River 

Mile 18.0) 

Stream Location; Clatsop County 

Source Location: 

Treatment facility is located at the end of 53rd 

Street in Astoria, Oregon 

Permit Writer: 

Garry L. Sage, EIT 

WQ-NWR- Source Control Section 

Telephone Number: 503.229.5690 

Source Categoiy: Major Domestic 

Treatment System Class: Level II 

Collection System Class: Level IV 
City of Astoria Evaluation Report 

Page 2 of 24 

TABLE OF CONTENTS PAGE 

Proposed Changes to This Permit 4 

Facility Background 5 

Introduction 5 

Facility Description 5 

Biosolids Management and Utilization 6 

Inflow and Infiltration (I&I) 6 

Pretreatment 7 

Pollutants Discharged 7 

Beneficial Use Analysis 9 

Receiving Stream Water Quality (WQ) Impacts 9 

Mixing Zone Analysis. 9 

Total Maximum Daily Loads (TMDLs) for Main Stem Columbia R.... 10 

Temperature Analysis 10 

Bacteria 11 

Chlorine Toxicity 12 

Ammonia Toxicity 13 

Dissolved Oxygen Reduction 13 

Groundwater 13 

pH 13 

Toxics Analysis , 14 

Permit Histoiy 14 

Anti-degradation Review 14 

Compliance Histoiy 14 

Permit Discussion 15 

Face Page 15 

Schedule A - Waste Discharge limitations 15 

Treated Effluent Discharged at Outfall 039 15 

Discharge Seasons 16 

BOD5 and TSS Concentration and Mass Limits 16 

BOD5 and TSS Removal Efficiency (Summer Season) 17 

BOD5 and TSS Removal Efficiency (Winter Season) 17 

pH Limits 18 

Temperature Limits... 18 

Bacteria 18 

Chlorine Residual 19 

Ammonia 19 

Mixing Zone and Zone of Immediate Dilution 19 

CSO Outfalls (001- 038) 20 

Groundwater Protection 20 

Schedule B - Minimum Monitoring and Reporting Requirements 20 

Influent Sampling 20 

Influent Measurement and Sampling 20 

Effluent Sampling for Outfall 039 21 
City of Astoria Evaluation Report 

Page 3 of 24 

PAGE 

Measurement & Sampling of Year-Around Effluent Parameters 21 

Temperature Measurements (May 22 - October 14) 21 

Ambient Metals Testing for the Columbia River 22 

CSO Outfall Monitoring (Outfalls 001-038) 22 

Discharge Monitoring Report (DMR) Procedures 22 

WET Testing. 22 

Five Day Reporting of SSOs 22 

Schedule C - Compliance Schedules and Conditions 22 

Schedule D - Special Conditions 23 

1. Operator Certification 23 

2. Groundwater 23 

3. Whole Effluent Toxicity (WET) Testing 23 

4. Emergency Response and Public Notification Plan 23 

5. Notification 24 

6. Facility Planning to Improve Winter % Removals 24 

Schedule-E - Pretreatment 24 

Schedule-F - General Conditions 24 

Attachments 

1. Treatment Facility Design Criteria & Background Information 

2. Discharge Monitoring Report Data Summaries 

3. BOD5 and TSS Percentage Removal Analysis 

4. Chlorine & Ammonia RPA for Toxicity 

5. Chlorine Limits 

6. Antibacksliding/Antidegradation Review 

7. Designated Beneficial Uses for the Main Stem Columbia River 

8. Basin-Specific Criteria (Main Stem Columbia River) 

9. Oregon's 2010 Integrated Report Database (WQL Status for Lower Columbia 

River) 

10. Temperature RPA 

11. Dissolved Oxygen RPA (Streeter-Phelps DO Model) 

12. Columbia River pH, Alkalinity, & Temperature Data 

13. pHRPA 

14. Metals RPA 

15. Amended Stipulation & Final Order (ASFO) No. WQMW-NWR-92-247 

16. Permit Milestones 

17. CSO Outfalls (001-038) 
City of Astoria Evaluation Report 

Page 4 of 24 

Proposed Changes to This Permit 

Schedule-A 

1) Summer season is redefined as May 22 through October 14, and winter season as October 15 

through May 21 [based on amended stipulation and final order (ASFO) WQMW-NWR-92-247 

signed on October 29, 2010]. 

2) Winter effluent mass loads are increased based on the design average wet weather flow 

(AWWF) approved by DEQ on December 7,2009. 

3) Summer season BOD5 and TSS percentage monthly average removal limits are increased to 

65% to comply with the federal "significant biological treatment" and "equivalent to secondaiy 

treatment" definitions. 

4) BOD5 and TSS percentage removals are calculated differently for the months of April-MayJune and September-October-November. 

5) Interim and final limits for bacteria are listed. Final limits for fecal coliform and enterococci 

bacteria replace current, interim __. coll bacteria limits on or before completion of Schedule-C 

construction. Final fecal coliform and enterococci limits are added to comply with DEQ's 

internal management directive (IMD) - "Bacteria Criteria for Marine and Estuarine Waters" 

(Section 10.0, Table-1). 

6) Interim and final limits for chlorine residual are listed subject to Schedule-C for re-construction 

of the chlorine contact chamber, and the addition of dechlorination and pH 

monitoring/adjustment facilities. Year-around, final effluent chlorine residual limits for daily 

maximum and monthly average are more stringent than current chlorine limits. 

7) Ammonia limits are removed from the permit per Section 303(d)(4) of the Clean Water Act 

(CWA); since the Columbia River is not water quality limited (WQL) for ammonia and/or 

dissolved oxygen. The removal of ammonia limits complies with Oregon's antidegradation 

rules under OAR 340-041-0004. An ammonia reasonable potential analysis (RPA) supports the 

elimination of ammonia limits per compliance with WQBELs. 

Schedule-B 

1) Add calculation for monthly average chlorine residual concentration. 

2) Add calculation for monthly average ammonia concentration [ammonia monitoring is retained 

in renewal permit even though limits are dropped (see above)]. 

3) Add calculations for BOD5 and TSS monthly average concentration. 

4) Provide one sample each per week for fecal coliform and enterococci bacteria. Calculate 

monthly median and percent exceeding 43 organisms per 100 mL for fecal coliform bacteria. 

Calculate monthly geometric mean for enterococci bacteria. 

5) Report sewage solids relocation &/or transport events. 

6) Reduce temperature monitoring for influent, effluent, and Columbia River maximum 

temperature to one annual measurement during August for each parameter. 

7) Modify "year-around CSO reporting requirements" to comply with ASFO WQMW-NWR-92-

247 language. 

8) Drop requirements for measurement of Columbia River salinity and velocity [not needed since 

mixing zone (MZ) study is complete]. 

9) Add ambient testing for Columbia River metals (quarterly for first two years, and semi-annual 

(winter and summer) for duration of the renewal permit). 

10) Annual WET testing per Schedule-D is referenced. 

11) Sanitary sewer overflow (SSO) reporting requirements are added. 

Schedule-C 

1) Schedule-C lists a compliance schedule for permittee's reconstruction of the chlorine contact 

basin, and the addition of dechlorination and pH monitoring/adjustment equipment. ScheduleC complies with DEQ's internal management directive (IMD) for Compliance Schedules in 

NPDES permits. 
City of Astoria Evaluation Report 

Page 5 of 24 

Schedule-D 

1) A groundwater protection clause (Item No. 2) is added. 

2) Whole effluent toxicity (WET) testing requirements for discharge to fresh water are updated, 

and amiual testing is required. 

3) Item No. 6 is added to gain additional information on treatment potential for improving winter 

season BOD5 and TSS percent removal levels. Submittal of an approvable facilities plan is 

required within 6-months of permit issuance. 

Schedule-F 

1) Schedule-F was extensively revised to comply with recent EPA Region-10 mandated changes. 

2) Schedule-F clarifies event reporting for permit violations and wastewater overflows. . 

Facility Background 

Introduction 

The City of Astoria operates a wastewater treatment facility located on the south bank of the 

Columbia River within city limits (Attachment-1). Wastewater (sewage) is treated and discharged 

to the Columbia River year-around at river mile 18.0, in accordance with National Pollutant 

Discharge Elimination System (NPDES) Permit number 102397. The current permit for this 

facility was issued on February 15,2002 and expired on January 31, 2007. 

The Department received a permit renewal application on September 20,2006. A renewal permit is 

necessary to discharge to state waters pursuant to provisions of Oregon Revised Statutes (ORS) 

468B.050 and the Federal Clean Water Act. The Department proposes to renew the permit. 

Currently the permit is under administrative continuation pending its renewal. 

Facility Description 

Astoria's wastewater treatment facility is a 3-cell facultative lagoon design with headworks, 

chlorine contact chamber, and mechanical aeration that was constructed in 1974 (Attachment-1). 

The ponds provide a treatment level "equivalent to secondary treatment," per 40 CFR Part 

133.105. Lagoon aeration is designed to reduce effluent BOD5 and ammonia. Chlorine is used 

for effluent disinfection. Dechlorination and pH adjustment/monitoring equipment are currently 

not installed at this facility. The existing chlorine contact basin must be rebuilt to improve 

bacteria kill to ensure that the facility can meet proposed limits for fecal coliform and enterococci 

bacteria (see compliance Schedule-C). 

The engineer who designed the facility determined the design average dry weather flow 

(ADWF). It is the estimated maximum daily average dry weather flow (May 1 to October 31) at 

which the design engineer expects the treatment facility to consistently meet all effluent limits. 

Diy weather flows do not include the high levels of infiltration and inflow (I&I) that are 

associated with Oregon winters on the west side of the Cascade Mountains. Therefore, the 

design ADWF is used mostly to estimate how much treatment capacity there is for organic loads. 

For this facility, the design ADWF = 4.2 million gallons per day (MGD). The current actual 

average dry weather, monthly influent flow (May 1 to October 31) for Years 2005-2010 was 2.2 
City of Astoria Evaluation Report 

Page 6 of 24 

MGD (Attachment-2). The peak month dry weather influent flow over the interval May 2005 

through July 2010 was 12.0 MGD (October 2009). Currently, this facility operates at 52% of its 

organic treatment capacity. 

During winter season for Years 2005-2010, the average influent monthly facility flow was 6.4 

MGD, and the peak monthly influent flow was 19.4 MGD (Attachment-2). For this facility, the 

design average wet weather flow (AWWF) = 12.6 MGD, and the design peak wet weather flow 

(PWWF) is approximately 20.0 MGD. Design wet weather flows represent available winter 

season treatment capacity at this facility. Based on recent treatment performance, this facility is 

operating at 51% of its winter season average monthly capacity. See the section below on I&I for 

additional discussion of winter flows, hydraulic capacity, and combined sewer overflows (CSOs). 

Biosolids Management and Utilization 

A biosolids management plan (BMP) is currently not required for this source. The City has not 

removed sewage solids from its lagoon system for many years. Schedule-B, Lb and Note 5 

require the City to record any action that results in movement within the treatment facility of 

sewage solids, and/or removal of sewage solids from the treatment facility. Under this renewal 

permit, sewage solids may be transported off-site by a licensed hauler for further treatment and 

disposal at a permitted facility. Should the City decide to produce its own biosolids for disposal, 

it must develop a Department approvable BMP. A draft BMP must receive a Public Notice prior 

to its implementation. DEQ requires a separate BMP Public Notice process when the draft BMP 

is not given Notice in conjunction with the renewal permit. Potential biosolids application sites 

in Clatsop County are evaluated first. Biosolids sites located outside of Clatsop County must 

receive a Public Notice that involves residents in the affected counties. All biosolids application 

sites must meet the site selection criteria set forth in Oregon Administrative Rule (OAR) 340-

050-0070. 

Schedule-D, Item No. 6 requires a study of the existing treatment facility for improvement of 

BOD5 and TSS monthly removal efficiencies during winter season. Part of this study must deal 

with Pond #1 sewage solids storage/removal. Additionally, Pond #1 must be evaluated as a 

septage receiving and treatment pond connected to the lagoon treatment system. The results of 

this study will enable DEQ and the permittee to determine the best way to handle sewage solids 

in the future. 

Inflow and Infiltration (I&I) 

The City of Astoria has a veiy old sanitary collection system made up in large part of combined 

sanitary and storm sewer systems (Attachment-1). Past practice has created a legacy of leaking old, 

combined sewers subject to overflow during most rain events. More recent construction has 

focused on sewer separation. Rainfall driven flows in the combined sanitary and storm collection 

system typically exceed the system capacity with overflows possible at the CSO points shown on 

Pages 1 and 2 of this draft permit. There are 38 CSO locations with 3 CSO outfalls listed as 

removed. CSO discharges go either to Young's River or to the Columbia River without treatment. 

The city is required under Astoria's amended stipulation and final order (ASFO) WQMW-NWR92-247 to continue separating its sanitary sewers from storm water flows. Considerable 
City of Astoria Evaluation Report 

Page 7 of 24 

construction has already occurred to remove storm water from the sanitaiy system. Under the 

ASFO, the City has committed to a long term construction program that will reduce the number of 

CSO points and the quantity of flow released at each CSO location. The City has determined that it 

will cost approximately $39 million in 2010 dollars to construct the facilities needed to meet the 

level of control required by the ASFO. CSO discharge points on Young's Bay and in the 

embayment area adjacent to the Alderbrook residential neighborhood are required to achieve a level 

of control subject to a 5-year return winter storm event and a 10-year return summer storm. All 

other CSO discharges points to the Columbia River shipping channel are required to achieve a 2-

year return summer storm and on average a six-in-a-winter storm level of control. The proposed 

level of CSO control should reduce the current volume of CSO discharges by approximately 96% 

in a typical rainfall year. 

Pretreatment 

Based on Astoria's population and lack of significant industrial sources, a pretreatment program 

is not needed at this time to protect influent quality. Under the current permit (Schedule-C, 

Condition No. 3) an Industrial Waste Survey was completed. The survey determined that there 

are no industrial sources. A pretreatment program is not required at this time. 

Pollutants Discharged 

Current Permit. The current permit allows the City of Astoria to discharge treated effluent from its 

wastewater treatment facility at Outfall 039 year-around. The current permit sets limits on the 

following pollutants: Five-day biochemical oxygen demand (BOD5) and total suspended solids 

(TSS); E. coli bacteria (daily maximum and monthly average); chlorine residual (daily maximum 

and monthly average); pH (maximum and minimum); ammonia (daily maximum and monthly 

average); effluent temperature (7-day mean maximum), daily maximum heat load, average monthly 

heat load; and pollutant removal efficiency for BOD5 and TSS. 

Proposed Permit. The proposed permit regulates most of the same pollutants with the following 

exceptions/changes: 

1. The percentage removal efficiencies1 for summer season BOD5 and TSS increase from 35% to 

65% to comply with minimum "equivalent to secondaiy treatment" standards; 

2. Winter mass loads for BOD5 and TSS are increased based on the Department's approval of the 

design average wet weather flow (AWWF) for this facility; 

3. Chlorine residual limits2 (maximum daily and average monthly) are more stringent; 

4. E. coli bacteria limits are replaced with fecal coliform and enterococcus bacteria limits 

(current permit's E. coli limits become proposed interim limits); and 

5. Ammonia limits are eliminated from the permit, however, monitoring requirements are 

retained in Schedule-B. 

Footnotes: 

Percentage Removal. A review of past Astoria permits found that the NPDES permit issued 

on January 13, 1993 (expired June 30, 1997) contained no percentage removal limits for BOD5 

and TSS. The lack of removal limits was apparently the result of pervasive CSO overflows 

throughout the combined sanitaiy system that could not be readily quantized for flow volume or 
City of Astoria Evaluation Report 

Page 8 of 24 

concentration. The renewal permit issued on February 15, 2002 (expired on January 31, 2007) 

included year-around 35% removal limits for BOD5 and TSS. The 35% removal limits for 

summer season are inadequate (see permit Schedule-A, Note 4 for a detailed explanation). The 

proposed summer season, percentage removal limits in Schedule-A are more stringent. Limits 

are increased to 65% to achieve the "equivalent to secondaiy treatment" level for this type of 

treatment facility. Recent Discharge Monitoring Report (DMR) data indicates that these limits 

can be met by the existing treatment facility (Attachment-3). 

Winter season removal efficiencies are discussed below under Permit Discussion, BOD5 and 

TSS Removal Efficiency (Winter Season). 

CI Limits. Effluent chlorine residual for fresh and salt water was modeled using DEQ's RPA 

spread sheet for chlorine and ammonia toxicity (Attachment^). Chlorine permit limits 

(Attachment-5) were established based on discharge monitoring report (DMR) data 

(Attachment-2), and on worst-case available dilution in the mixing zone. 

Schedule-C in the proposed permit establishes a 2.5 year process leading to the addition of 

dechlorination at Astoria's wastewater treatment facility. Within 2.5 years of permit issuance, 

permittee must complete a remodel of the existing chlorine contact basin to control and reduce 

chlorine residual in the facility's effluent. Interim permit limits for chlorine residual apply, until 

construction listed under Schedule-C is completed. When dechlorination is added to this 

facility, final permit limits will become effective. 

Bacteria Limits. Fecal coliform and enterococci bacteria limits are proposed in Schedule-A, 

La (3) for the protection of marine waters and estuarine shellfish growing waters, per OAR 

340-041-0009 (1) (b). Astoria discharges to the Columbia River Estuary at river mile 18.0, 

where there is a potential for shellfish growing and/or harvest. Currently, shellfish growing and 

harvesting are not practiced in the vicinity of Astoria's outfall. 

The proposed permit contains interim limits for E. coli bacteria and final limits for fecal 

coliform and enterococci bacteria. By note following Schedule-A, La (3), the proposed permit 

states: 

* Should bacteria data indicate that the existing chlorine contact chamber can meet final 

permit limits for fecal coliform and enterococci bacteria prior to completion of ScheduleC construction; DEQ will require immediate implementation of the final bacteria limits. 

Enterococcus standards apply to all discharges downstream of the western edge of Puget Island 

at approximately RM 39.0; given rule-based definitions of estuary and recreational waters 

developed by the Division of State Lands (DSL) and the Department of Land Conservation and 

Development (DLCD). Astoria discharges to mixed salt and fresh water with an approximate 

annual average salinity of 10 parts per thousand (ppt); i.e. estuarine waters. These conditions 

mandate enterococcus bacteria limits for the proposed permit. Schedule-A, Note 10 discusses 

these limits. 
City of Astoria Evaluation Report 

Page 9 of 24 

When permit limits for fecal coliform and enterococci bacteria become permanent, __. coli 

testing is no longer required (Schedule-B, Lb Note 4). Schedule-A, Notes 9 and 10 list 

specifics relating to fecal coliform and enterococci bacteria limits. Limits are taken from 

DEQ's internal management document (IMD) for Bacteria Criteria for Marine and Estuarine 

Waters (December 30,2010), Table-1. 

Ammonia Limits. Ammonia limits are listed in the current permit. The Department proposes 

to eliminate ammonia limits because recent reasonable potential analyses (RPAs) indicate no 

potential for ammonia toxicity. The Department's RPA spread sheets for ammonia toxicity are 

contained in Attachment-4. Ammonia DMR data are included in Attachment-2. No reasonable 

potential for acute or chronic ammonia toxicity is indicated under worst-case conditions. 

Attachment-6 contains an Antidegradation Review Sheet, and a discussion prepared by the City 

of Astoria relating to the proposed reduction in ammonia limits. Normally, renewal permit 

limits cannot be less stringent than current permit limits. In Astoria's case, current ammonia 

limits are eligible for a reduction because they are not "final limits." The ammonia limits listed 

in the current permit (issued February 15, 2002) never took effect because mutual agreement 

and order (MAO) No. WQ/M-01-284, Paragraph 8.(b) established interim limits that are still in 

force. The MAO was signed on the same day as the current permit was issued. 

The City's argument in Attachment-6 follows the outline in EPA's NPDES Permit Writer's 

Manual (Exhibit 7-2, P. 7-5, September 2010) for application of antibacksliding requirements. 

Ammonia limits are based on state standards. Water quality standards for ammonia are attained 

per the Clean Water Act (CWA) Sections 402(o)(l)/303(d)(4). The Columbia River has no 

attaimnent problems associated with ammonia or dissolved oxygen per 303(d)(4)(B) (effluent 

ammonia does not cause a measurable reduction in dissolved oxygen). The proposed 

elimination of ammonia limits is consistent with DEQ's antidegradation policy. It complies 

with effluent guidelines and water quality standards, and beneficial uses are not impaired. 

Beneficial Use Analysis 

The designated beneficial uses of the main stem Columbia River are listed in Oregon 

Administrative Rule (OAR), Chapter 340, Division 041, Table 101A (Attachment-7). Beneficial 

uses include: public and private domestic water supply, industrial water supply, irrigation, 

livestock watering, fish & aquatic life, wildlife and hunting, fishing, boating, water contact 

recreation, aesthetic quality, and commercial navigation and transportation. Division 041, Table 

101B lists, "Fish Uses Main Stem Columbia River." Fish uses are, "salmon and steelhead 

migration corridors at 20 °C." Further clarification offish use designations is provided in Figures 

230A and 230B. Both figures show North Coast Basin, as well as mainstem uses (Attachment-7). 

Astoria's outfall discharges to the main stem Columbia River with its salmon and steelhead 

migration corridor. 

Receiving Stream Water Quality (WO) Impacts 

Mixing Zone Analysis 

In September 2008 the City submitted its revised mixing zone (MZ) study. DEQ approved the 
City of Astoria Evaluation Report 

Page.l0of24 

City's study on December 19, 2008. The MZ study focused on worst-case, summer season 

conditions in the Columbia River; i.e. the 7-day average low-flow with a reoccurrence interval of 

10-years (7Q10 low-flow). Based on the study, worst-case dilution at 7Q10 low-flow was 

determined to be approximately H_i at the zone of initial dilution (Z1D) boundary and 36.0 at the 

MZ boundary. The Department's water quality modeling, reasonable potential analyses (RPAs) for 

the proposed pennit are based on these dilution values for worst-case conditions. Dilutions are 

listed in the proposed permit in Schedule-A, La (1); as a quick reference for future permit 

evaluations. These dilutions are used in Schedule-D, Special Condition No. 3, to set whole effluent 

toxicity (WET) testing parameters. 

Total Maximum Daily Loads (TMDLs) for Main Stem Columbia River 

The main stem Columbia River is subject to TMDLs for dioxin and dissolved gas (OAR 340-041-

0103, Attachment^). Astoria's discharge is not affected by either TMDL, since it does not 

contribute to violations of either parameter. 

Temperature Analysis 

To protect the beneficial uses of salmon and steelhead migration (Attachment-7, Table 101B), the 

Columbia River in the vicinity of the outfall must not exceed 20 °C, under worst-case, low-flow 

summer conditions. According to DEQ's 2010 Integrated Report Database (Attachment^), the 

Columbia River is water quality limited (WQL) for temperature year-around for its entire length in 

Oregon.* 

*The temperature determination relative to Astoria appears to be over conservative; i.e. for 

year-around discharge to an estuary at RM 18.0. DEQ's current policy is to list the entire river 

for temperature when violations are discovered at one or more locations far upstream. 

DEQ's Point Source Thermal Calculator RPA spread sheets (Attachment-10) indicate that there is 

no reasonable potential for an effluent driven temperature violation at the MZ boundary or for 

effluent mixed with 25% of the available 7Q10 low flow during summer season. RPAs indicate 

that Astoria's discharge does not contribute measurably to river warming. Adequate dilution is 

available in the MZ and river to keep effluent temperature effects within required limits under 

worst-case summer season conditions. 

Temperature limits in the current permit are proposed for the renewal permit. Temperature limits 

cannot be eliminated on the basis of the above negative temperature RPA findings. The 

antidegradation arguments used to justify the elimination of ammonia limits (Attachment-6) are not 

applicable to temperature because the receiving waters are WQL for temperature (Attachment^). 

The CWA Section 303(d)(4)(A) does not allow a limit reduction for non-attainment waters, unless 

those limits are based on a total maximum daily load (TMDL) or WLA. Astoria's existing 

temperature limits are not based on a TMDL or WLA; therefore a revision is not allowed. As stated 

above, the Department proposes to use current temperature limits in the renewal permit. 

Thermal Plume Requirements 

Oregon Administrative Rule (OAR) Chapter 340, Division 041 lists temperature control 

requirements for effluent discharges to waters of the State. The proposed Astoria renewal permit 
City of Astoria Evaluation Report 

Page 11 of 24 

must comply with the following "Thermal Plume" language in OAR 340-041-0053. 

(2) (d) Temperature Thermal Plume Limitations. Temperature mixing zones and effluent limits 

authorized under 340-041-0028 (12) (b) will be established to prevent or minimize the following 

adverse effects to salmonids inside the mixing zone: 

(A) Impairment of an Active Salmonid Spawning Area. This is not a possibility for Astoria's 

discharge, since there are no spawning beds in the vicinity of Outfall 039. 

(B) Acute Impairment or Instantaneous Lethality. Acute impairment or instantaneous lethality is 

prevented or minimized by limiting potential fish exposure to temperatures of 32.0 degrees 

Celsius (89.6 degrees Fahrenheit) or more to less than 2 seconds, Astoria's discharge 

temperature never approaches this temperature threshold. 

(C) Thermal Shock. Thermal shock caused by a sudden increase in water temperature is 

prevented or minimized by limiting potential fish exposure to temperatures of 25.0 degrees 

Celsius (77.0 degrees Fahrenheit) or more to less than 5 percent of the cross section of 100 

percent of the 7Q10 low flow of the water body. Astoria's discharge has not reached 25.0 °C 

based on DMR data (Attachment-2). MZ dilation provides immediate temperature reduction 

even under worst-case, low-flow conditions. 

(D) Migration Blockage. Unless the ambient temperature is 21.0 degrees or greater, migration 

blockage is prevented or minimized by limiting potential fish exposure to temperatures of 21.0 

degrees Celsius (69.8 degrees Fahrenheit) or more to less than 25 percent of the cross section of 

100 percent of the 7Q10 low-flow of the water body. 

Astoria's effluent does not violate this criterion based on the Thermal Calculator runs discussed 

above. The Columbia River at Outfall 039 is approximately 5 miles wide. 

Influent and effluent temperature data for this treatment facility (beginning in January 2006) are 

contained in Attachment-2. 

Bacteria 

Bacteria control criteria for Astoria's sewage treatment facility are based on DEQ's IMD, "Bacteria 

Criteria for Marine and Estuarine Waters." This IMD was issued on December 30,2010. The IMD 

requires that both fecal coliform and enterococcus bacteria limits be listed in Schedule-A of the 

permit. 

The following limits are proposed for fecal coliform bacteria: 

Fecal Coliform Bacteria. Shall not exceed a median concentration of 14 organisms per 

100 mL, and not more than 10% of the samples shall exceed 43 organisms per 100 mL 

(Schedule-A, La (3)). 

Schedule-A, Note 9, Fecal Coliform Bacteria states: 
City of Astoria Evaluation Report 

Page 12 of 24 

Limits are measured at the end-of-pipe. These fecal coliform limits are taken from 

Section 10.0, Table-1 of DEQ's IMD for Bacteria Criteria for Marine and Estuarine 

Waters (December 30, 2010) per "Suggested Criteria Language for Permit." It is 

proposed that additional monthly samples may be taken over the number specified in 

Schedule-B, 1. b of this permit. All samples collected during the month must comply in 

aggregate to the limits specified in Schedule-A, 1 .a (3). 

The following limits are proposed for enterococci bacteria: 

Enterococci Bacteria. Shall not exceed a geometric mean concentration of 35 organisms 

per 100 mL (Schedule-A, La (3)). 

Schedule-A, Note 10, Enterococci Bacteria states: 

Limits are measured at the end-of-pipe. If a single sample exceeds a concentration of 35 

organisms per 100 mL, then five consecutive re-samples may be taken at four hour 

intervals beginning within 28 hours after the original sample was taken. If the log mean 

of the five re-samples is less than or equal to 35 organisms per 100 mL. a violation shall 

not be triggered. This enterococci limit is taken from Section 10.0, Table-1 of DEQ's 

IMD for Bacteria Criteria for Marine and Estuarine Waters (December 30, 2010) per 

"Suggested Criteria Language for Permit." 

Bacteria limits in the proposed permit are based on the above fecal coliform and enterococci 

bacteria standards. E. coli bacteria limits from the current permit are retained as interim limits, 

until Schedule-C construction is completed. Schedule-B, Lb, Note-4 requires monitoring for E. 

coli, .fecal coliform, and enterococci bacteria at permit issuance. As discussed above, a note at 

the bottom of Schedule-A, La. (3) provides for the adoption of final bacteria limits upon 

demonstration that the existing chlorine contact basin can meet final permit limits. Ultimately, 

proposed final bacteria limits must be met when Schedule-C work is finished. 

Chlorine Toxicity 

Astoria's wastewater treatment facility uses chlorine to disinfect its effluent and meet bacterial 

limits listed in Schedule-A of the proposed renewal permit (see above). Currently, discharged 

effluent is not dechlorinated to remove unacceptable toxicity, Interim and final chlorine residual 

concentration limits are listed in Schedule-A, La (3) of the renewal pennit. Interim chlorine 

limits apply, until Schedule-C work is complete. 

Chlorine toxicity was evaluated using the Department's RPA spread sheet (Attachment-4). 

Effluent DMR data for chlorine residual is summarized in Attachment-2 for the interval January 

2007 through May 2011. The chlorine RPA determined that chlorine is present, year-around at 

toxic levels in effluent discharged from Astoria's wastewater treatment facility. Chlorine 

residual limits necessary to control toxicity are listed in Attachment^. The most stringent limits 

(salt water, summer season) are proposed as year-around chlorine residual limits. Proposed 

limits for daily maximum and monthly average chlorine residual are listed in Schedule-A, 1 ,a (3) 

of the proposed permit; and current chlorine limits are listed as proposed interim limits. The 
City of Astoria Evaluation Report 

Page 13 of 24 

proposed limits are more stringent than the interim (current) chlorine limits. DEQ believes that 

proposed chlorine limits can be met at this treatment facility once dechlorination equipment is 

installed per Schedule-C, 

Ammonia Toxicity 

Effluent ammonia data are listed in Attachment-2 for the years January 2007 through May 2011. 

As discussed above, the RPA for ammonia (Attachment-4) determined that effluent discharges at 

Astoria's treatment facility do not cause ammonia toxicity (acute and chronic); respectively in the 

ZID or MZ. Based on the ammonia RPA, the Department proposes to eliminate ammonia limits 

from the proposed permit. 

The elimination of effluent ammonia limits is consistent with the antibacksliding/antidegradation 

discussion presented above under "Pollutants Discharged," Footnote #4. The complete 

antidegradation discussion/review is presented in Attachment-6. 

Continued year-around ammonia monitoring per Schedule-B, Lb is proposed to track treatment 

facility performance in removing ammonia, and to provide a data base for the next permit 

renewal cycle. 

Dissolved Oxygen Reduction 

The Department's Streeter-Phelps Dissolved Oxygen Model spread sheet was used to investigate 

dissolved oxygen (DO) levels associated with a summer season discharge under worst-case 

conditions (Attachnient-11). Source and river temperature data were taken from Attachments-2 

& -12. Modeling results indicate that the DO drop in the receiving stream is < 0.005 mg/L 

(insignificant) after complete mixing with the effluent discharge. Model results are consistent 

with the allowed DO reduction for this type of point source discharge. 

Groundwater 

Appropriate sections of the Groundwater Prioritization Worksheet are included in the Department's 

files for this facility. The Permittee's wastewater treatment and disposal system includes 

impoundments for sewage solids. No biosolids are produced as discussed above. At this facility, 

sewage solids are stored in lined treatment lagoons that prevent leaching of nutrients to 

groundwater. This facility poses no risk to groundwater. The proposed permit (Schedule-A, 1. d) 

requires proper facility operation and maintenance to protect groundwater. Schedule-D, Special 

Condition No. 2 reiterates that groundwater must be protected. 

EH 

DEQ's pH Spread Sheet (Attachment-13) evaluates Astoria's effluent for pH compliance. 

Columbia River data collected at the Beaver Army Terminal (RM 55) is used to model ambient 

conditions (Attachment-12), Effluent data is listed in Attachment-2. Based on worst-case, 

summer low-flow conditions, the Department found no reason to change current pH permit 

limits. The Department proposes to use current pH limits in the renewal permit [Schedule-A, 1 .a 

(3)]. 

As part of the Schedule-C work listed in this permit, the city proposes to add pH 
City of Astoria Evaluation Report 

Page 14 of 24 

adjustment/monitoring equipment to its treatment facility. pH adjustment is sometimes needed 

in late summer season when effluent drops below the permitted daily pH range. 

Toxics Analysis 

Attachment-14 contains RPA spread sheets for metals toxicity pertaining to Astoria's effluent. An 

• effluent, metals data summary; and ambient metals data for the Columbia River [Beaver Army 

Terminal (RM 55)] is also attached. The spread sheet for fresh water toxicity indicates that all 

metals evaluated have no potential for acute or chronic toxicity under worst-case, summer 7Q10 

low-flow discharge conditions. When the RPA is run with the same metals data and a discharge to 

salt water, copper is flagged with a reasonable potential for acute toxicity. One copper sample used 

in this analysis (17.1 ug/L) is 36 % greater than the next largest copper datum. If this value is 

excluded, there is no reasonable potential for acute copper toxicity (salt or fresh water). 

The proposed permit (Schedule-B) requires continued metals monitoring during the permit term. 

Metals data will be collected for influent, effluent, and the Columbia River (near Astoria's 

discharge). The collection of metals data must comply with the criteria and quantitation limits 

specified in Schedule-B, Note 3. 

Following two years of metals testing (counted from permit issuance); the Department will re-evaluate 

metals data by reasonable potential analysis (RPA). DEQ will determine at that time whether the permit 

should be re-opened and permit limits added (Schedule-B, l.e). 

Given additional metals data, it will be possible to improve the RPA for metals toxicity at the next 

permit renewal. As it now stands, there is no significant likelihood that any metal evaluated exerts 

acute or chronic toxicity under worst-case, low-flow conditions established for Astoria's discharge. 

PERMIT HISTORY .. . 

Anti-degradation Review 

An Anti-degradation Review was completed with a recommendation to proceed with this permit 

action. A copy of the review sheet is located in Attachment-6. 

Compliance History 

Since the last permit renewal, no treatment facility improvements were made. The sanitaiy 

collection system, however, was improved to reduce the number and volume of CSO discharges. 

Emergency power was installed at major pump and lift stations. Overflow weirs in the collection 

system were raised to retain more sewage during surcharge events. Inline storage facilities were 

constructed to capture sewage that previously went to CSO outfalls. Considerable storm water 

(inflow and infiltration) was removed from the sanitaiy collection system with recent construction. 

The Department signed an amended and stipulated order (ASFO) with the City on October 29, 

2010 for continued sanitary sewer improvements (Attachment-15). The City must eliminate by 

December 1, 2022 untreated CSO discharges, subject to the storm frequencies specified in 

Paragraph 11 .a of the ASFO at all remaining CSO discharge points, consistent with the facilities 

plan approved by the Department. 
City of Astoria Evaluation Report 

Page 15 of 24 

Since the current permit was issued (February 15, 2002), the facility has experienced permit 

violations and enforcement actions as follows (see Attachment-16 for a complete listing): 

DATE 

13Sep2002 

4Jun2004 

28Sep2004 

28Jun2005 

3May2007 

29Jan2008 

9Oct2008 

30Jul2008 

10Nov2010 

ACTION 

Penalty Demand Notice (PDN) WQMNWR-02-150 

PDN WQM-NWR-04-101 

PDNWQM-NWR-04-117 

PDN WQM-NWR-05-009 

PDN WQM-NWR-07-003 

PDN WQM-NWR-07-206 . 

PDN WQM-NWR-08-148 

PDN WQM-NWR-08-187 

Warning letter (WL-WQ-NWR-10-

0101) 

LIMIT VIOLATIONS 

$250 civil penalty for failure to submit 

a temperature management plan. 

$3000 civil penalty for failure to 

complete Phase-1 CSO overflow 

control projects. 

$1700 civil penalty for failure to install 

operational CSO monitoring 

equipment. 

$21,300 civil penalty for unsanctioned 

CSO discharges. 

$6000 civil penalty for unsanctioned 

CSO discharges to Youngs Bay. 

$3750 civil penalty for numerous DMR 

effluent limit violations. 

$100 civil penalty for failure to meet 

interim chlorine residual limit on 

18Aug2008. 

$200 civil penalty for chlorine limit 

violations. 

WL for October weekly BOD effluent 

concentration violation. 

PERMIT DISCUSSION 

Face Page 

The Permittee is authorized to construct, install, modify, or operate a wastewater collection, 

treatment, control, and disposal system. Permits year-around discharge of treated effluent to the 

Columbia River at Outfall 039 located at RM 18.0. Permit lists combined sewer overflow (CSO) 

points located in the City's collection system (see Attachment-17 for CSOs 001-038 locations). 

Discharges from the City's wastewater treatment facility must be within limits set by Schedule-A, 

and subsequent permit schedules. All other discharges are prohibited. 

Schedule-A. Waste Discharge limitations 

Treated Effluent Discharged at Outfall 039 

The proposed permit sets limits on effluent discharges from this facility. Limits on effluent 

discharges to the Columbia River include: 

• 5-day biochemical oxygen demand (BOD5), 

« Total suspended solids (TSS), 
City of Astoria Evaluation Report 

Page 16 of 24 

o E. coli bacteria (interim limit), 

• Fecal coliform and enterococci bacteria (final limits), 

• pH, 

© Chlorine residual (interim and final), 

• BOD5 and TSS removal efficiency 

« Effluent temperature 7-day maximum, 

• Maximum daily heat load, and 

• Monthly average heat load. 

Discharge Seasons 

It is proposed that summer and winter seasons listed in Schedule-A correspond to the timing 

established in the City's ASFO for combined sewer overflow control (Schedule-A, Note 1). 

BODs and TSS Concentration and Mass Limits: 

Based on main stem Columbia River minimum design criteria listed in OAR 340-041-0104 (4), 

wastewater treatment resulting in a monthly average effluent concentration of 20 mg/L for BOD5 

and TSS (or equivalent control) must be provided for periods of low stream flow (Attachment-8). 

A minimum of secondary treatment (or equivalent control) is required for high stream flow. 

Since Astoria treats its wastewater with a 3-cell facultative lagoon system, "equivalent to 

secondary treatment" standards apply.' The Department proposes to continue using year-around 

"equivalent to secondary treatment" standards for this facility. "Equivalent to secondaty 

treatment" for this facility is defined as a monthly average concentration limit of 30 mg/L for 

BOD5 and 50 mg/L for TSS (Schedule-A, Note 3). 

The summer season mass load limits for BOD5 and TSS are based on the facility's design average 

diy weather flow (ADWF) = 4.2 MGD. and the monthly average BOD5 and TSS concentration 

limits listed above. Winter season mass loads are based on the design average wet weather flow 

(AWWF) = 12.6 MGD, and the monthly average BOD5 and TSS concentration limits. 

The limits for treated e 

Parameter 

BOD5 

TSS 

ffluent at Outfall 039 (May 22 -

Average Effluent 

Concentrations 

Monthly 

30 mg/L 

50 mg/L 

Weekly 

45 mg/L 

75 mg/L 

October 14) are: 

Monthly 

Average 

lb/day 

1100 

1800 

Weekly 

Average 

lb/day 

1600 

2600 

Daily 

Maximum 

Lbs 

2100 

3500 

Calculations: 

BOD. 

(a) 4.2 MGD x 8.34 #/gal x 30 mg/L = 1100 lbs/day monthly average; 

(b) lbs/day monthly average x 1.5 - 1600 lbs/day weekly average; and 

(c) lbs/day monthly average x 2.0 = 2100 lbs/day daily maximum. 
City of Astoria Evaluation Report 

Page 17 of 24 

TSS 

(a) 4.2 MGD x 8.34 #/gal x 50 mg/L = 18001bs/dav monthly average; 

(b) lbs/day monthly average x 1.5 = 2600 lbs/day weekly average; and 

(c) lbs/day monthly average x 2.0 - 3500 lbs/day daily maximum. 

The limits for treated effluent at Outfall 039 (October 15 - May 21) are: 

Parameter 

BOD5 

TSS 

Average Effluent 

Concentrations 

Monthly 

30 mg/L 

50 mg/L 

Weekly 

45 mg/L 

75 mg/L 

Monthly 

Average 

lb/day 

3200 

5300 

Weekly 

Average 

lb/day 

4700 

7900 

Daily 

Maximum 

Lbs 

6300 

10500 

Calculations: 

BOD5 

(a) 12.6 MGD x 8.34 #/gal x 30 mg/L = 3200 lbs/day monthly average; 

(b) lbs/day monthly average x 1.5 = 4700 lbs/dav weekly average; and 

(c) lbs/day monthly average x 2.0 = 6300 lbs/day daily maximum. 

TSS 

(a) 

(b) 

(c) 

12.6 MGD x 8.34 #/gal x 50 mg/L = 5300 lbs/dav monthly average; 

lbs/day monthly average x 1.5 - 7900 lbs/dav weekly average; and 

lbs/day monthly average x 2.0 = 10500 lbs/day daily maximum. 

The City of Astoria's current wastewater treatment facility is capable of meeting the above 

proposed mass load limits based on composite sampling. 

BOD, and TSS Removal Efficiency (Summer Season) 

For Astoria's lagoon treatment system, a minimum monthly average percentage removal = 65% for 

BODs and TSS is proposed (Schedule-A, Note 4). 

May 22-October 14 

Parameter 

BODs Removal Efficiency 

TSS Removal Efficiency 

Limitations 

BOD5 removal efficiency shall not be less than 

65 % monthly average. 

TSS removal efficiency shall not be less than 65 

% monthly average. 

BOD, and TSS Removal Efficiency (Winter Season) 

A 35% monthly average removal efficiency is proposed for BOD5 and TSS based on past practice, 

and the effects of a combined sewer system (Schedule-A, Note 5). Attachment-3 discusses the 

reasons for maintaining 35% monthly average removal efficiencies for BOD5 and TSS: 
City of Astoria Evaluation Report 

Page 18 of 24 

A removal efficiency standard of 85% for BOD5 and TSS is established in 40 CFR Part 

133.102. This is "secondary treatment" for POTWs. Trickling filters and facultative lagoons 

are allowed limits considered "equivalent to secondary treatment" through 40 CFR Part 133.105 

(this rule allows both BOD5 and TSS removal efficiency of 65% as a monthly average). States 

may further adjust removal efficiency (for either or both BOD5 and TSS) through one of two 

exception processes. The exception process fox facilities with combined sewers is found in 40 

CFR Part 103(a). These limits need to be established on a case-by-case basis. Astoria fits in 

this categoiy. By rule they should only be applied during wet weather. Calculated removal 

should be valid for the life of the facility, and only updated if conditions change or the facility is 

updated. Schedule-D, special condition No. 6 requires a treatment facility evaluation to 

determine whether there is potential for improving percentage removals at the existing 

treatment facility. The study is required within 6-months of permit issuance. Based on the 

facility evaluation, the Department will determine whether "changed conditions" warrant an 

increase in percentage removals. 

Proposed winter season removal efficiencies (equal to current % removals) are as follows: 

October 15-Mav 21 

Parameter 

BOD5 Removal Efficiency 

TSS Removal Efficiency 

Limitations 

BOD5 removal efficiency shall not be less than 

35 % monthly average. 

TSS removal efficiency shall not be less than 35 

% monthly average. 

pH Limits. The proposed pFI limits in Schedule-A are the same as those in the current permit. 

Temperature Limits. Proposed temperature limits in Schedule-A are the same as those in the 

current permit. See Schedule-A, Notes 13 and 14 for details on using these limits. 

Bacteria 

The proposed permit limits discharges of E. coli, fecal coliform, and enterococci bacteria to 

waters of the state. Interim E. coli bacteria limits replaced with final fecal coliform and 

enterococci bacteria limits per Schedule-C completion. Should bacteria testing indicate that the 

existing chlorine contact chamber can achieve final bacteria limits before Schedule-C work is 

finished; final bacteria limits will be applied early (note following Schedule-A, La (3)). 

The permit proposes the following bacteria limits (Schedule-A, Notes 9 & 10). 

Parameter (Year-around) 

E. coli Bacteria (Interim Limits) 

Fecal Coliform Bacteria 

Limitations 

Shall not exceed 126 organisms per 100 mL 

monthly geometric mean. No single sample shall 

exceed 406 organisms per 100 ml. 

Shall not exceed a median concentration of 

14 organisms per 100 mL; and 10% of the 

samples shall not exceed 43 organisms per 

100 mL. 
City of Astoria Evaluation Report 

Page 19 of 24 

Enterococci Bacteria Shall not exceed a geometric mean 

concentration of 35 organisms per 100 

mL. 

Interim __. coli bacteria limits remain in effect, until Schedule-C construction is completed; or unti 

DEQ determines that the existing chlorine contact basin can meet the final limits (whichever occurs 

first). 

Chlorine Residual 

Year-around chlorine residual interim and final limits (daily maximum and monthly average) are 

proposed (Schedule-A, La (3)). Interim limits are taken from-the current permit. Final limits were 

developed by RPA using the most stringent discharge conditions (see discussion above). The 

permittee must comply with the interim chlorine limits, until Schedule-C construction is 

completed. The Schedule-C compliance schedule provides for the design and reconstruction of 

the chlorine contact basin for enhanced effluent disinfection; and adds dechlorination and pH 

monitoring/control equipment to comply with final chlorine residual and pH limits. Schedule-A, 

Note 11 discusses chlorine residual compliance testing. 

Parameter (Year-around) 

Chlorine Residual (Interim Permit Limits) 

Chlorine Residual 

Limitations 

The end-of-pipe effluent limits for chlorine 

are: daily maximum limit ~ 0.3 mg/L and 

monthly average limit = 0.1 mg/L (Note 7). 

Shall not exceed 0.11 mg/L daily maximum 

and 0.04 mg/L monthly average (Notes 8 & 

in. 

Ammonia 

The Department proposes to eliminate ammonia limits from the renewal permit based on recent 

RPAs (Attachment), and compliance with EPAs antibacksliding/antidegradation requirements 

(Attachment-6). See DEQ's ammonia antidegradation discussion above under Pollutants 

Discharged (Footnote #4). 

Mixing Zone and Zone of Immediate Dilution 

Mixing Zone: Except as provided for in OAR 340-045-0080, no wastes shall be discharged and 

no activities shall be conducted which violate Water Quality Standards, as adopted in OAR 340-

041; except in the following defined mixing zone: 

The Regulatory Mixing Zone (RMZ) is that portion of the Columbia River contained within a 

radius extending two hundred (200) feet from the outfall discharge point(s) in all directions. 

The Zone of Immediate Dilution (ZID) shall be defined as that portion of the allowable mixing 

zone that is within a twenty (20) foot radius of each outfall discharge point. 

The Department believes that the mixing zone, as described above, is appropriate for this discharge. 

Beneficial uses of the receiving stream will be protected, and the mixing zone meets the criteria in 

rule. 
City of Astoria Evaluation Report 

Page 20 of 24 

CSO Outfalls 001-038 

Permittee must comply with the performance standards for its 38 combined sewer overflow (CSO) 

outfalls (listed on Pages 1 and 2 of this permit); and with the schedule for attainment thereof, in 

accordance with the provisions of the amended stipulation and final order (ASFO) WQMW-NWR92-247 (Attachment-15) consistent with the control program set forth in the permittee's CSO 

Facilities Plan. The CSO Facilities Plan is a Long Term Control Plan under the requirements of the 

United States EPA's Combined Sewer Overflow Control Policy. Attachment-17- shows CSO 

outfall locations. 

It is proposed that Schedule-A list the Nine Minimum Controls for operation and maintenance of 

the combined sewer system, as set forth in EPA's Combined Sewer Overflow Control Policy. 

The Nine Minimum Controls are applicable to this permit. 

Groundwater Protection 

The renewal permit proposes to prohibit all activities at this facility that could cause an adverse 

impact on the existing or potential beneficial uses of groundwater. 

Schedule B - Minimum Monitoring and Reporting Requirements 

The renewal permit proposes that the laboratory used by the permittee to analyze samples have a 

quality assurance/quality control (QA/QC) program to verify the accuracy of sample analysis. If 

QA/QC requirements are not met for any analysis, the results shall be included in the report, but not 

used in calculations required by the proposed permit. When possible, the permittee shall re-sample 

in a timely manner for parameters failing the QA/QC requirements, analyze the samples, and report 

the results. 

In 1988, the Department developed a monitoring matrix for commonly monitored parameters. 

Proposed monitoring frequencies for all permit parameters are based on this matrix. They 

correspond to those applied to facilities of similar size and complexity in the state. Proposed 

monitoring frequencies are unchanged from the current permit. 

Influent Sampling 

Influent parameters must be monitored as specified in the permit at the indicated locations. The 

permit proposes that grab samples, measurements, and composite samples be taken at the 

headworks just upstream of the Parshall flume. Septage deliveries are sampled after screening at 

the headworks. All measurements for influent temperature (summer season) and samples for toxics 

are taken in the same location. 

Influent Measurement and Sampling: 

o Total flow (daily measurement, continuous recorder), 

® Flow meter (annual calibration), 

o BODs and TSS concentration (1 day/week by 24-hour, composite sampler), 

® BOD5 and TSS concentration (monthly average calculation for each), 

* BOD5 and TSS mass load calculations (weekly and monthly average), 

« pH (3 days/week by grab sample), and 
City of Astoria Evaluation Report 

Page 21 of 24 

• Metals sampling by composite sampler (take 2 samples/year for 5 years with one sample during 

winter and one during summer). 

Effluent Sampling for Outfall 039 

At permit issuance, the WWTP effluent sampling point is located at the chlorine contact basin's 

discharge weir. Following the installation of dechlorination and pH adjustment equipment at this 

treatment facility, the effluent sampling point will be located immediately downstream of the 

dechlorination and pH adjustment zones. The permit proposes to take effluent grab and composite 

samples, and measurements at the same location. Samples for effluent toxics and temperature 

measurements are taken at the same location. Monitoring for ambient surface water (Columbia 

River) must be located upstream and outside of the regulatory MZ, per Schedule-B, Note-3 (last 

paragraph). 

Measurement and Sampling of Year-Around Effluent Parameters: 

• Total flow (daily measurement, continuous recorder); 

• Flow meter (annual calibration); 

• BOD5 and TSS concentration (1 day/week by 24-hour, composite sampler); 

• BOD5 and TSS concentration (monthly average calculation); 

• BOD5 and TSS mass load calculations (weekly and monthly average), 

• BOD5 and TSS percent removal (monthly average calculation); 

• pH (3 days/week grab sample); 

• E. coli bacteria (one grab sample/week); 

• E. coli bacteria (monthly geometric mean calculation); 

• Fecal coliform bacteria (one grab sample/week); 

• Fecal coliform bacteria (monthly median and percent exceeding 43 organisms per 100 mL 

calculations); 

• Enterococci bacteria (one grab sample/week); 

• Enterococci bacteria (monthly geometric mean calculation); 

• Pounds Chlorine used for disinfection (measurement 5-days/week); 

• Chlorine residual grab sample (5-days/week); 

• Chlorine residual (monthly average calculation); 

• Bisulfite residual concentration (5-days/week); 

• Ammonia as N (1 day/week as 24-hour composite sample); 

• Ammonia as N (monthly average calculation); 

• Semi-annual metals sampling by 24-hour composite method (one summer and one winter 

sample each year for permit term); 

• Sewage solids management (record of each relocation and/or transport event); and 

Temperature Measurements (May 22 - October 14): 

» Influent daily maximum temperature (one measurement during August each year); 

• Effluent daily maximum temperature (one measurement during August each year); and 

• Columbia River daily maximum temperature (one measurement during August each year). 
City of Astoria Evaluation Report 

Page 22 of 24 

Ambient Metals Testing for the Columbia River: 

Grab samples must be taken quarterly for the first two years following permit issuance, and semiannual thereafter (one winter and one summer). 

CSO Outfall Monitoring (Outfalls 001-0381 

The permittee must monitor each combined sewer outfall (CSO) discharge point identified on 

Pages 1 and 2 of the proposed permit. Permittee must record the following concerning overflows 

at each CSO point, per direction of ASFO WQMW-NWR-92-247 (see Schedule-B, Note 6): 

• Date and start time (record of each occurrence); 

• Duration of CSO event (measurement); and 

• Volume of CSO event (calculated). 

Discharge Monitoring Report (DMR) Procedures 

This section requires that DMRs be submitted monthly, and lists mandatory DMR content. 

WET Testing 

Whole effluent toxicity (WET) testing is proposed with reference to Schedule-D, Condition No. 3 

for testing frequency and procedures. 

Five Day Reporting of SSOs 

It is proposed that sanitaiy sewer overflows (SSOs) be reported within 24-hours with a written 

report to follow within 5-days, unless waived by the Department. Written reports are to use 

DEQ's SSO Reporting Form. 

Schedule C - Permit Compliance Conditions 

Schedule-C proposes a compliance schedule for treatment facility upgrades. The compliance 

schedule applies to the re-construction of the existing chlorine contact basin, and the addition of 

dechlorination and pH control/monitoring equipment. These changes will ensure that final 

Schedule-A limits for chlorine residual and bacteria are met. Interim Schedule-A limits for 

chlorine residual and bacteria are listed to bridge the construction interval (2.5 years following 

permit issuance) leading to the required facility improvements. Schedule-A, Notes 7 & 8 

reference Schedule-C. 

By Schedule-C, a project status report must be submitted each year on the permit issuance 

anniversary date. The permit may be re-opened and modified to be consistent with conditions or 

mitigation measures imposed as a result of EPA's Endangered Species Act consultation with 

NMFS and USFW on DEQ's rule authorizing the use of this compliance schedule. Failure to 

meet the final chlorine residual, and bacteria limits listed in Schedule-A by the date set in 

Schedule-C is a violation of the NPDES permit. The Permittee is required to meet the 

compliance dates established in Schedule-C. No later than 14 days following each milestone, the 

permittee must notify DEQ in writing of its compliance or noncompliance with the interim 

requirements. Any reports of noncompliance must include the cause of noncompliance, any 

remedial actions taken, and the probability of meeting the next scheduled requirements. 
City of Astoria Evaluation Report 

Page 23 of 24 

The Department feels that the proposed schedule for the above facility upgrades is as short as 

technically feasible. The proposed permit will probably be issued in October 2011. A facility plan, 

pre-design report, and final plans and specifications must be approved by the Department prior to 

construction start. Financing arrangements must be made by the City. Winter season construction 

is unlikely, since high influent flows require additional treatment flexibility. Based on these 

constraints, the Department feels that these proposed facility upgrades can be completed in 2.5 

years. The compliance schedule is considered by the Department to comply with DEQ's 

Compliance Schedule IMD for "as-soon-as-possible." 

Schedule D - Special Conditions 

Schedule-D of the proposed permit includes six Special Conditions. 

1. Operator Certification. The permittee shall comply with Oregon Administrative Rule (OAR), 

Chapter 340, Division 049, Regulations Pertaining to Certification of Wastewater System 

Operator Personnel. The permittee shall have its wastewater system supervised by one or 

more operators who are certified at a classification and grade level specified in the permit. 

The permittee's wastewater system may not be without supervision for more than thirty (30) 

days: and the permittee is responsible for ensuring the wastewater system has a properly 

certified supervisor available at all times to respond on-site. 

2. Groundwater. The permittee is not required to perform a hydro-geologic characterization or 

groundwater monitoring during the term of this permit provided the facilities are operated in 

accordance with the permit conditions; and there are no .adverse groundwater quality impacts 

(complaints or other indirect evidence) resulting from the facility's operation! 

3. Whole Effluent Toxicity (WET) Testing. Annual, fresh water WET testing is proposed 

during the permit term. DEQ's lab determined that WET salt water testing is not required, 

since the effluent plume spends 6-seconds or less within a bottom hugging salt water wedge 

before rising to the fresh water surface. Two tests must be conducted in two different 

summer seasons, and two tests must be conducted in two different winter seasons. After the 

initial four tests, the permittee must conduct annual WET tests in rotating winter/summer 

seasons. Acute and chronic test procedures are proposed with test dilutions simulating the 

actual worst-case dilutions found at the ZID and MZ boundaries. 

4. Emergency Response and Public Notification Plan. It is proposed that permittee develop and 

maintain an Emergency Response and Public Notification Plan, per Schedule-F, Section-B, 

Conditions 7 and 8. The Plan must inform citizens in a timely manner of the location, time, 

and magnitude of untreated sewage discharges. Permittee must annually update the Plan's 

spill notification list. Permittee must educate satellite collection systems (those discharging 

to Astoria's collection system) concerning monitoring and reporting requirements for sanitary 

sewer overflows (SSOs). Miles Crossing Sanitary District is one such satellite collection 

system. 
City of Astoria Evaluation Report 

Page 24 of 24 

5. Notification. The permittee shall notify the DEQ Northwest Region - Portland Office in 

accordance with the response times noted in the General Conditions of this permit, of any 

malfunction so that corrective action can be coordinated between the permittee and the 

Department. 

6. Facility Planning to Improve Winter Season Percentage Removals for BODs and TSS. Schedule-A, 

Note 5 references this special condition. The permittee is required to submit within 6 months of 

permit issuance an approvable facility plan that accesses how sewage solids build-up in lagoon Cell 

#1 impacts treatment and BOD5 and TSS percentage removals. Future CSO flow capture per 

continuing CSO removal work required by ASFO No. WQMW-NWR-92-247 must be considered. 

Alternatives for maximizing BOD5 and TSS percentage removals during winter season under 

different treatment scenarios must be discussed. The removal of the sewage solids build-up from 

lagoon Cell #1 must be evaluated. Ammonia and solids transfers among lagoon cells must be 

addressed. 

Schedule E - Pretreatment Program 

The proposed permit does not require a pretreatment program based on documentation submitted 

during the current permit cycle. 

Schedule F - General Conditions 

The General Conditions were revised and issued on September 18, 2009. A summary of the 

changes is as follows: 

(1) There are additional citations to the federal Clean Water Act and CFR, including 

references to standards for sewage sludge use or disposal; 

(2) There is additional language regarding federal penalties; 

(3) Bypass language has been made consistent with the Code of Federal Regulations; and 

(4) Overflow language has been modified; 

• Formerly the language stated that overflows in response to the five or ten year 

event would not violate the permit, 

• Now it states that overflows are prohibited, and 

• DEQ will continue to exercise enforcement discretion with respect to overflows 

consistent with the provisions of the Bacteria Rule (OAR 340-041-0009). 

These General Conditions are standard additions to NPDES permits of this type. Their inclusion 

is proposed for this draft permit. 

GLS: Astoria NPDES Fact Sheet 16Sept2011.docx/Revised: 27Oct2011