**Document EPA** 

**Comment # EPA Comment**  **SEHSC Response**

Study Plan 1 GENERAL PROCESS DESCRIPTION OF INDUSTRIAL PLANT OPERATIONS FOR EACH SITE: The ECA states (Appendix 1, page 20), “A general process description of the industrial plant operations involving D4 shall be provided. A more detailed description, including a written narrative and process flow diagram(s) of the wastewater treatment system employed at the sites shall also be provided (e.g., at a minimum consistent with what was provided in each facility's discharge permit application.” The general process descriptions provided for the Momentive Performance Materials (MPM) Friendly (Study Plan, section 9.2) and W aterford (Study Plan, section 10.2) sites are not adequate. These descriptions do not sufficiently describe the processes that contribute D4 containing wastewaters to the on-site W WT P. Thus, it is not clear how D4 containing wastewaters are generated at these sites.

Additionally, the W WT P process flow diagrams (PFDs) provided for W acker – Adrian (Study Plan, figure 7-2), MPM – Friendly (Study Plan, figure 9-2), and MPM – W aterford (Study Plan, figure 10-2) are of a poor scan quality and are difficult to read. The PDFs cannot be adequately reviewed in their current visual quality. Additional descriptive narratives on industrial plant operations involving D4 at the Friendly and W aterford sites have been incorporated into Sections 9.2 and 10.2 of the Study Plan.

A higher quality version of Figures 7-2, 9-2, and 10-2 has been included in the Study Plan Revision 1.

Study Plan 2 NORMAL OPERATING CONDITIONS: The ECA (Appendices 1, 4, 5, 7 and 8) states, “Samples shall be collected during normal plant operations and during such times that effluent flow rates from the wastewater treatment system are representative of the normal plant operations.” The ECA further states that, “the criteria or means that are used by the facilities to determine normal operating conditions will be documented in the site specific Sampling Plans.”

The Study Plan includes a discussion of normal operating conditions for each of the four direct discharge sites and establishes that ERM will verify that the W WT Ps are functioning under normal operating conditions and flow rates prior to sampling (sections 7.2.3, 8.2.3, 9.2.3, and 10.2.3). Although these parameters are important, greater detail is needed. Specifically, process equipment that feeds D4 containing wastes to the W WT P should also be operating under normal conditions as well. This point is made by the MPM – W aterford site (Study Plan, section 10.2.3) and should also be included in the respective sections for the other three direct discharge sites.

The W WT P process flow diagrams provided for W acker- Adrian (figure 7 2), MPM- Friendly (figure 9 2), and MPM- W aterford (figure 10-2) are of a poor scan quality and are difficult to read. The PDFs cannot be adequately reviewed in their current visual quality. The Adrian, Carrollton, and Friendly facilities indicated that D4 was discharged year-round and that there was no individual process that generates all or the majority of the D4 discharged to the W WT P. The following sentence has been added to Sections 7.2.3, 8.2.3, 9.2.3, and 10.2.3: W e will contact the site contact prior to mobilization of field crews to verify that the manufacturing/processing units that discharge wastewater containing D4 to the W WT P and the W WT P itself are functioning under normal operating conditions and flow rates.” Additional text describing the WWT Ps operators’ responses to the question of how they monitor and respond to potential upsets has been added to Section 3.2 of the Study Plan Revision 1.

A higher quality version of Figures 7-2, 9-2, and 10-2 has been included in the Study Plan Revision 1.

Study Plan 3a Sections 10.1 and 10.2 (regarding MPM- W aterford) of the draft Study Plan make some statements that require further clarification:

Section 10.1 states that Outfall 020 is on the Hudson River’s east bank. However, it appears that the outfall is on the west bank based on Figure 10-1. The text has been revised to state that Outfall 020 is on the Hudson River’s west bank.

Study Plan 3b Section 10.2.2 makes reference to Outfalls 021 and 022, but makes no mention of Outfall 020 (the outfall to be sampled). It is unclear if the references to Outfalls 021 and 022 are correct, or if one of these outfall numbers should be 020. Outfall 020 flows into Outfall 022. Outfall 020 is the permitted effluent sample location for the facility, in accordance with its SPDES permit. Outfall 021 will not be sampled because it receives only storm, cooling and non-process wastewater. This has been clarified in Section 10.2.2 of the Study Plan.



### 1 of 3**Document EPA** 

**Comment # EPA Comment**  **SEHSC Response**

Study Plan 4a Comment 4.a. The ECA requires that surface water, sediment and biota sampling locations shall be collected as close as reasonably possible to the effluent outfall provided adequate mixing of the discharge and receiving water has occurred (Appendix 8). SEHSC in its Study Plan has noted problems with establishing adequate mixing at some facilities and proposed using 100 m as the sampling location. Please revise text to include the rationale for how the proposed approach satisfies the requirements of the ECA. Response 4a:

The following text has been added to Section 2.5.6.1 of the Study Plan (now addressing the DD W WT Ps) to clarify how the sampling location will be verified to satisfy the requirements of the ECA:

"To verify that sampling takes place within or downstream of the effluent plume for any of the W WT Ps without an NPDES-permit defined mixing zone, one of the following methods may be used: visual observation of the plume, dye tracing, and/or evaluation of temperature-conductivity profiles. At many W WT Ps that discharge treated wastewater to a river, the plume can be clearly observed in the receiving water and sampling can be conducted in the center of the plume based on visual observation. In the absence of a visual plume, either dye tracing or temperature-conductivity profiles should be used. The dye test consists of adding a dye at the effluent discharge and evaluating the water color visually as the dye moves with the effluent plume. The temperature-conductivity profile method consists of taking temperature and conductivity measures horizontally across the river at the 100 m potential sampling location.” SOP #130 describes the conditions for the use of each method and the procedures to be followed in more detail.

The above statement also applies to municipal W WT Ps, as indicated in revised Section 2.5.6.2 (see also the response to Comment 4.c, below). A statement similar to the first sentence in the text in quotes was added to each of the site-specific sections for W WT Ps without an NPDES permit-defined mixing zone.

Study Plan 4b Alternatively, at sites where adequate mixing cannot be established EPA would consider an approach where 3 required samples could be collected incrementally downstream of the outfall (e.g., at 100 m, 500 m and 1000 m) instead of at a single location at 100 m. This approach may bracket the point where adequate mixing has occurred. The inclusion of two additional downstream sampling locations may confound the results due to the influx of other water and chemicals along the rivers where the DD W WT Ps discharge. Thismay also esult in different methods or analysis (e.g., sample compositing or averaging) being used for the DD sites than are used at other sites. Therefore, this change has not been incorporated into the Study Plan. W e believe that the additional measures noted in response to 4a will address concerns about establishing mixing zone and additional sampling noted by EPA would not be necessary.

Study Plan 4c Wi th respect to the remaining sites, EPA expects that sampling locations are to be determined by establishing the point where adequate mixing has occurred. The defined mixing zone within the NPDES permit or by calculating the size of the mixing zone with an EPA approved method may be useful methods to establish adequate mixing. One problem with removing the use of the mixing zone methodology based on the four direct discharge sites in the program is that the full set of sampling sites is not yet known. Given that the Hudson and Ohio Rivers likely will be the largest rivers in the sampling plan, it may be premature to decide that the mixing zone technique is broadly inapplicable. If the other water bodies are more in line with the River Raisin site (Adrian, MI) then the distance to complete mixing may be useful for the following ten sites. The issue with the Carrollton, Friendly, and W aterford W WT Ps was that they discharge to large rivers without diffusers, which slows the dilution of the effluent. Section 2.5.6.2 of the Study Plan was revised to clarify how the sampling location will be selected and verified for municipal W WT Ps:

“Of the 11 W WT Ps described in Sections 11.0 to 21.0, only Boulder, CO and Gresham, OR had permit-defined mixing zones. Because of the difficulties found during the modeling for the DD W WT Ps and the lack of correspondence between the predicted and actual location of the plume at our field training site (Carrollton, KY), the mixing zone for the other nine municipal W WT Ps (including a Non-Industrial backup) was not modeled. Instead, the same 100 meter distance used for the DD W WT Ps was used as the potential sampling location. Procedures to confirm that sampling is conducted within or downstream of the effluent plume at the selected location at the time of the sampling are described in Section 2.5.6.1 and SOP #130.”

Study Plan 4d The Study Plan (section 7.2.2) states that the effluent is discharged via outfall to a wetlands zone that conveys the waste water to the River Raisin. This is likely an unusual circumstance and consideration should be given to measuring the sediment concentrations in the affected wetlands. If there are releases of D4, a significant portion may be retained in this wetland environment. EPA recognizes that this would not be how the Parties have typically conceptualized the monitoring location specified by the ECA but would likely generate more useful exposure assessment information. See photograph 4 in Figure 7-6 for more details. The SEHSC disagrees with EPA’s recommendation. The following sentence was added to Section 7.2.2 to address the comment:

“No sampling is proposed to occur in the wetland as such sampling within the confines of the facility property is outside the scope of what is prescribed in the ECA for this Testing Program" as this would introduce additional variability into the monitoring results.



### 2 of 3**Document EPA** 

**Comment # EPA Comment**  **SEHSC Response**

Study Plan 5a The ECA (Appendix 8, page 48) states, “Biota sampled shall include benthic species collected in sediment of the receiving water body and two species of fish, if practicable, of different trophic guilds, in the receiving water body.” In the submitted material it is not apparent that this will be a priority as abundance is repeatedly listed as a criterion for fish sample collection. However, it is not necessary to collect a significant number of larger fish to have sufficient tissue mass for analysis. Once the threshold for mass of tissue required for analytical needs has been met, the goal of collecting fish from two different trophic levels should supersede the abundance criterion in all sections of the sampling plan (for each site), in the standard operating procedures and in the QAPP. Section 3.8.6.1 of the Study Plan indicates: “Two species of fish will be sampled at each location, if practicable, from different trophic guilds” and Section 3.8.6.2 of the Study Plan indicates: “The two most abundant species collected will be selected for laboratory analysis; if practicable, the species selected for analysis should be from different trophic guilds.” Similarly, Section 4.3.6, #2 of Standard Operating Procedure (SOP) 060 Collection of Fish Samples indicates: “Identify the two most abundant species **from each trophic guild** . If these species each have either five (5) single fish weighing at least 50 grams each OR sufficient numbers to prepare five (5) composite samples (consisting of a combination of several fish) of at least 50 grams each, then assign these species as Catch Species 1” and “Catch Species 2” and skip to Step 5.” SOP 060 proceeds to indicate that if this requirement is not met, then the two most abundant species should be selected for analysis.

Study Plan 5b The collection of benthic invertebrates should avoid species such as mussels, clams or crayfish to provide consistency across sites in the program due to identified differences in collection permits. The following text has been added in Section 3.8.5.2 of the Study Plan: "As requested by EPA, mussels, clams, and crayfish will not be included with the benthic organisms samples at any W WT P during the D4 study. To address the possibility that the 100 grams of benthic organisms specified in the ECA may not be collected in a reasonable period of time, SOP #040 and the QAPP include some flexibility to adjust sample size for primary and retain benthic organism samples. In the event that 100 grams of benthic organisms cannot be obtained, the absolute minimum mass of benthic organisms required to complete all laboratory analyses is 25 grams.”

In addition, the following statement has been added to each site-specific sampling plan section of the Study Plan: “At the request of EPA, mussels, clams, or crayfish will not be collected during the D4 study at any W WT P, to provide consistency across sites in the program.”

Study Plan 6a Study Plan section 2.2, Table 2-1 is listed as having the contact information for the signatory companies. Table 2-1 was not included with the submission Table 2.1, with contact information for the signatory companies and other study personnel, was included in the Study Plan Revision 1.

Study Plan 6b Study Plan section 3.1, Table 3-1 is listed as having a list of personal-care products that can be used by the samplers, but table 3-1 does not contain that information. The reference to Table 3.1 was removed from Study Plan Section 3.1. Please see Appendix A to the QAPP which provides guidance on preventing sample contamination from silicone use.

Study Plan 6c Include a copy of the NPDES permits for all sites in the program. The NPDES permits for all sites in the program have been included in the Study Plan.

Study Plan 6d Study Plan sections 7.4 & 8.4, the literature sources for the fish species that may be present need to be identified for the Adrian, MI and East Carrollton, KY sites. Currently “a review of various literature sources” or “the results of a 2008 biological study” are the only references. The literature sources should be identified and added to the references list. The literature source for Study Plan Section 8.4 (i.e., ORSANCO, 2009) has been included in the Study Plan. However, the literature source for Section 7.4 (Dodge, 1998) was inadvertently left out. This information has been incorporated into the Study Plan.



### 3 of 3

## Document **EPA Comment**  **# EPA**  **Comment SEHSC Response** 

QAPP 1 Modifications to the Study Plan (including site specific sampling plans) shall follow procedure identified in the ECA and codified in 40 CFR 790.68. Although not a requirement, EPA encourages SEHSC to develop and include in the QAPP contingency plans for (a) the major and minor Study Plan (including site-specific sampling plans adjustments and schedule changes related to potential challenges encountered during field work activities) and (b) criteria for determining if post-implementation notifications to EPA are preferable to pre-implementation notifications. A new Section 2.9.5 was added to the QAPP with the following text to clarify the procedures for Study Plan and QAPP Modifications:

“Modifications to the Study Plan or QAPP, if required, would be completed in accordance with 40 CFR 790.68, 40 CFR 790.62(c), and Section X of the ECA. The Study Plan, QAPP, and SOPs provide for flexibility

to accommodate reasonably foreseeable circumstances during sampling and analysis; therefore, the submittal of Study Plan or QAPP addenda should not be required to complete the study . Procedures for managing and documenting deviations from the field and analy tical SOPs, including notification to EPA, are described in QAPP Sections 3.2.1.7 and 3.4.2, respectively .”

QAPP 2 Representatives from both laboratories are required to sign the QAPP; in particular, the project manager and the QA manager from each laboratory

must sign the QAPP. In addition, the database software and how stored information will be recorded, archived and transmitted amongst the participants must be described in the QAPP with greater detail and specificity

. The PM and QAM from both laboratories were added to the QAPP’s Approval Page. Section 3.10.4 of the QAPP was revised to provide additional detail about the EQuIS database, including information describing the database and software version numbers, the storage/archival of information, and the transmittal of information amongst the study participants. Database record storage and retention were already described and data archival and retrieval are described in Sections 2.9.6 and 3.10.6 of the QAPP Revision 0, respectively

. Note that Section 3.10.6 was also modified to remove the hard-copy documents storage, archival, and retrieving procedures. All files will be stored electronically

.

QAPP 3 Further detail must be provided in the QAPP to describe the data quality objectives (DQOs) for the analy tics and under what conditions data may

be rejected. A procedure for who would be responsible for determining how to handle rejected data and considerations for replacement of rejected data must be described in the QAPP. The QAPP must also identify where rejected data will be discussed in the final or interim reports. Rejected data must be presented in one of the reports, not only in the bulk raw data submission. Please refer to Group A7, Quality Objectives and Criteria for Measurement Data and B5, Quality Control Requirements. Additional detail was added to the Section 2.7.2.2 of the QAPP to describe DQOs for the analyses and QC samples and to identify potential scenarios that may result in data being rejected. The following text was added to Section 5.3.1 of the QAPP to describe potential replacement of rejected data: “In the event that test data are rejected, the determination to replace rejected data will ultim ately

be made by

SEHSC and EPA based on the amount of usable data collected, the objectives of the study , and the number and ty pe of rejected data.”

Sections 2.9.7 and 5.3.2 of the QAPP were revised to include statements specifying that (1) rejected data, if any , would be described in the next Interim Report to EPA and in the data usability report to be included in the study’s Final Report, and (2) all data, including any rejected data, would be presented in the Final Report.

## QAPP 4 The QAPP states that primary samples will be disposed of by the laboratory

30 days after submitting the data package to EPA and the retained samples will be disposed of following QA verification. Based on the frequency of Interim and Final Reports, both of these disposal triggers will likely occur before EPA has an opportunity to review the raw and sum ma ry data from the analysis. The QAPP

mu st be revised to allow EPA sufficient time to review this data. To ensure that USEPA has time to review sample results prior to sample disposal, Section 3.3.1.1 of the QAPP was revised to specify that retain samples and primary sample volume remaining after extraction was disposed of 60 days after submittal of the Interim or Final Report that includes the associated raw and summary data. However, in some cases (for example, Interim Progress Report due more than 40 or 69 days after sample collection), none of the samples will be within the analy tical holding-tim e periods shown in Table 3-1 at the time indicated in the previous sentence, because the longest holding time is 69 days from sample collection (for benthic organisms and fish). The footnote in Table 3-1 has been modified in the QAPP.

Because of the volatility of D4 in water and the short holding time for water-matrix samples (14 days), surface water, influent, and effluent retain samples will be extracted upon receipt at ALS and held for later analysis, if needed.

To help ensure that EPA has time to review data before extracts expire, the laboratory will prioritize analyses of aqueous samples, so that the laboratory data package can be issued before the end of the retain samples holding time. EPA will be provided finalized analy tical data packages by

ERM upon receipt from ALS so that EPA can review the data as soon as possible. Each data packages transmittal will be accompanied by information on the associated retain sample or retain sample extract holding times and expiration dates. If the laboratory PM/QAM and the ERM Analy tical Coordinator determine that a retain sample should be analy zed, then EPA will be provided notification and the rationale for each retain sample analysis. These data exchange and communication procedures will be added to the QAPP.

DEFICIENCIES AND CLARIFICATIONS:

Deficiencies and needs for clarification were identified by comparing the QAPP to the enclosed table of requirements in the ECA and EPA’s 2002 QAPP guidance. The identified deficiencies

mu st be addressed in a modified QAPP covering the direct discharge and W WT P sites. The following commentary addresses deficiencies and needs for clarification presented on the aforementioned table of requirements.

Note, signatures and dates will be added when QAPP is approved. It is also necessary

for a representative of each of the labs to sign the QAPP. Comment noted.

A1

## Must add a representative from the laboratories to the QAPP signature list. The PM and QAM from both laboratories have been included in the QAPP Approval Page.

Table 2-6 does not provide the Data Quality Objectives (DQOs), but rather summarizes the DQO process for this program. As the QAPP and supporting documents address the DQO process for this program, Table 2-6 is redundant and unnecessary because the DQOs for this program are the performance and acceptance criteria provided in Tables 2-7 through 2-9. The title of Table 2-6 was changed to "Summary of DQO Process". The inclusion of the output from the DQO Process, as presented in Table 2-6, is consistent with the 2002 QAPP guidance which states "The outputs from the Agency's recommended systematic Planning process, the Data Quality Objective (DQO) Process, are ideally suited to addressing the first component of this elem ent."

(1) See comments under Section B5 below regarding development of DQOs for sampling and analy tical precision Section 3.5 of the QAPP (and any where else the issue was relevant) was revised to describe duplicate samples as QC samples and RPD criteria from the D4 analytical SOPs were included in Tables 2-8 and 3-4. (2) See EPA Comment #(2) under Section B5 below regarding developing a DQO for Relative Percent Difference (RPD) between pairs of field spikes to these tables. Section 3.5 of the QAPP (and any where else the issue was relevant) was revised to describe duplicate samples as QC samples, and RPD criteria from the D4 analytical SOPs were included in Tables 2-8 and 3-4.
(3) Please provide info. on how bias will be assessed (i.e., qualitatively

or quantitatively) and how sensitivity will be assessed (i.e., MDLs, LOQ, etc.). Information on how bias and sensitivity will be assessed was provided in Tables 2-8 and 5-3 of the QAPP Revision 1. Table 2-8 has been modified to include the information for the QC samples.

(4) EPA suggests adding depth measurement to Table 2-7. The im portance of collecting samples at a certain depth was stated, thus this info. should be included in the QAPP. EPA suggests adding the instrument that will be used to perform this assessment and the instruction manual's performance criteria. Additionally

, EPA suggests adding the instrumentation that will be used for all

me asurements and to add the sensitivity for water quality

. Wa ter depth measurement was added to Table 2-7 of the QAPP. To the extent possible, instrumentation was identified in Table 2-7 and typical sensitivity information was provided based on

ma nufacturer's specifications. Table 2-7 was also revised to specify that if alternative equipment were used, they

would be of comparable sensitivity

. A1

A7

## (5) Footnote 1 in Table 2-8 indicates that field spike QC samples that do not meet the target limit "will raise questions that must be resolved prior to acceptance of the data." Please describe the ty pes of questions that may be anticipated, the steps that will be undertaken to resolve them, and the criteria that will be considered in evaluating acceptance of the data. Section 2.7.2.2 of the QAPP was revised to describe examples of issues that could be raised by field spike QC sample results and examples of the steps that would be taken to resolve each issue. A reference to QAPP Section 2.7.2.2 was added to Footnote 1 in Table 2-8.

(6) The term "Field Blank" in Table 2-8 and throughout the QAPP is too vague and inconsistent (e.g., reference material field blank, split sample unspiked (field blank), lab water field blank, surface water field blank). The QAPP, including Table 2-8, was revised to use terminology from the ECA and to avoid the generic term "field blank".

EPA suggests revising the column headings in Table 2-5 to clarify that the reported numbers are per site per event (instead of per site). Labels for each of the rows at the bottom of Table 2-5 should start w/ the word "Total". Additionally , it's confusing that the

num bers reported in the columns do not sum to the totals listed in the bottom rows. EPA suggests revising the table format to better indicate the split between the top and bottom of the tables (e.g., double border or shading), and adding a footnote to explain how the totals are calculated. Table 2-5 was revised as requested.

EPA suggests adding sampling locations for sediment and benthic as discussed in response to study plan. Not all W WT P are specified as of this date, as expected. Comment noted. The QAPP specifies that sampling locations information is provided in the sitespecific sections of the Study Plan. B1

## EPA suggests including info. on the headspace left w/in each of the sample bottles. In general, “headspace requirements” are for sample handling not analytical reasons. D4 has a very large Henry’s Law Constant and will escape water and partition into air, unless there is a hydrophobic matrix in the water the D4 can partition into.

Biota (fish and invertebrates) are hydrophobic and will retain D4; there is no reason to control headspace as long as sample container is sealed. Therefore, there are no special headspace requirements for biota.

Biosolids and sediment samples will be homogenized in the sample jars before aliquoting the individual analy

tical samples. There must be enough space in the jars so that the sediment is not spilled during the process. Although Sections 3.2.1.3 and 3.2.1.4 of the QAPP Revision 1 specify that jars for biosolids and sediments will be filled two-thirds full, SOPs 030 and 040 reflect the most recent decision of the team with respect to the sample volume for the solid matrices: approximately 20 grams per jar. Sections 3.2.1.3 and 3.2.1.4 of the QAPP will be modified to reflect the “approximately

20 grams per jar” in the next submittal.

All the water sam ples are extracted in the original sample jars, so sufficient room must be present to add the 10 mL of hexane/internal standard solution for the extraction. The LDPE squares are added to provide a hydrophobic matrix to which D4 will adsorb. This minimizes the loss/escape of the D4 into the headspace. Both the field SOPs (010 and 020) and Sections 3.2.1.1 and 3.2.1.2 of the QAPP Revision 1 specify that jars will be filled with approximately 50 mL +/- 10 mL sample (which is approximately half full for a 4-ounce sample jar).

This information will be added to the corresponding sections of the QAPP.

Presently , only

sampling equipment is provided in this section. However, Sect. 3.6.1 identified additional equipm ent that are used to determine water depth, scales, electrofishing, etc. The additional equipm ent provided in Sect. 3.6.1 pertain to sampling and therefore should be included in the list of equipment provided. To clarify the issue, Sections 3.2.1 and 3.6.1 of the QAPP have been revised to include the following statement:

"Each field SOP in Appendix B includes a list of the equipment required to perform sampling or sample support activities.”

However, the list of equipment shown in the sampling SOPs covers all foreseeable equipment that

ma y be used at a W WT P based on the known river conditions and may not all be required for a

Sam ple hold tim e is not provided in this section, however, it is

me ntioned as a stability study in section 3.4.4. EPA suggests providing how long each sam ple will be stored from sampling until analysis in this section. Maximum holding time is not a B2 element per the 2002 QAPP guidance. A reference to holding tim es provided in Table 3-1 has been added to Element B3, Section 3.3.1.1 of the QAPP . The reference to Table 3-2 in Section 3.3.1.1 has been corrected to Table 3-1. B2

## Information is presented w/in the QAPP. However, page 31 indicates that sample container, minimum sample volume, preservation and maximum storage requirements are presented in Table 3-2. Table 3-2 shows the analy tical methods. Need to make sure that tables and figures are referenced consistently throughout the document. The reference has been corrected to Table 3-1.

The chain-of-custody

procedures provided for Field QC samples is confusing and incomplete. Section 3.3.2.1 of the QAPP states "COC forms will not identify field QC samples, such as field blanks or field spike samples. Field QC samples will be designated following the procedures presented in Section 3.2.5.2 of the QAPP." However, Section 3.2.5.2 of the QAPP does not exist. Section 4.0 of SOP 100 (Field Sample Custody) states "COC forms will not identify

field QC (QC) samples, such as field blanks or field spike samples. Field QC samples will be designated following the procedures presented in Section 3.5.1 of the QAPP." However, Section 3.5.1 of the QAPP does not discuss custody of QC samples. Please describe how custody of field QC samples will be maintained and documented. The QAPP has been revised as follows to describe how field QC samples will be identified: (1) Section 3.3: Sample Handling and Custody (QAPP Element B3) was revised to identify that the handling and custody

procedures described therein cover both investigative and QC samples. (2) The statement "COC forms will not identify field QC samples, such as field blanks or field spike samples." was removed from Section 3.3.2.1. (3) The QAPP and all SOPs except for 070 and 100 were revised to correctly reference QAPP Section 3.2.4 for sample designation, including field QC samples.

SOP 070 (Sample Labeling, Packaging, Marking, and Shipping) and SOP 100 (Field Custody) in the Study

Plan Revision 1 incorrectly refer to Sections 3.2.2.2 and 3.5.1 of the QAPP, respectively

, for sample designation. These references will be corrected to Section 3.2.4 of the QAPP, as well as in the Study

Plan.

As previously

mentioned under QAPP Element B2 Sampling Methods Requirements, EPA suggests including info. on sample headspace. Specifically , will there be headspace in the extracted sample vial ready

for analysis and how long will the sam ple wait in the autosampler before being analy zed. Any effects to the

me asurements caused by wait tim e in the auto sampler before analysis shall be described. This information is not relevant for QA and has not been included in the QAPP. Once the D4 is extracted into either the hexane or tetrahydrofuran solvents, it is stable and will not be lost in a closed container. There is also a stable isotope labeled D4 internal standard present to account for any analy te loss due to adsorption, evaporation, or other process. The wait time will not affect the analy tical response.

To address EPA's concerns about headspace in sample jars, QAPP Section 3.4.4 will be revised to indicate D4 stability

in solvents after extraction is not affected by headspace. B3

## Individuals responsible for corrective actions. This is not covered in the QAPP. EPA suggests adding text that specifies the responsible party

for corrective actions. Corrective actions have been incorporated in the Laboratory QAMs included as Appendices G and H to the QAPP. Laboratory SOPs specific to Corrective Actions (ALS-Kelso SOP CE-QA008 "Non Conformity

and Corrective Action" and ALS-SLC SOP LAB-020 “Nonconformance / Corrective Action Procedures”) have been included in the QAPP.

Needed laboratory

turnaround time. This is not covered in the QAPP. EPA suggests adding text that specifies the lab analysis turnaround time. Section 3.4 of the QAPP has been revised to state:

"Final analy

tical results will be provided on a standard maximum 30-business day turn-around time from sample receipt. This turn-around time is sufficient for comply ing with the tim eline for completion of the D4 monitoring program prescribed by the ECA.” (1) EPA suggests adding a discussion of QC requirements for duplicate investigative sam ples, including the developm ent of DQOs for sampling and analy tical precision, as appropriate. Section IX.A of the ECA requires the submission of a QAPP prepared in accordance w/ EPA guidance (USEPA Guidance for QA Project Plans, QA/G-5). Section 2.2.5 of EPA QA/G-5 describes the purpose of QC and provides guidance on the content for QC for field sampling programs including blanks, spikes, and split samples. For example, Section 2.2.5 of EPA QA/G-5 states "Replicate samples and split samples are commonly used to denote the level of precision in the measurement or collection system." Duplicate investigative samples are clearly a critical QC elem ent of the sampling process design for this program regardless of their identification as "Study Sam ples" versus "QA Sam ples" w/in the ECA. For example, per the ECA, "Duplicate samples are used to evaluate between-sample variability and Section 3.5 of the QAPP (and any where else the issue was relevant) has been revised to describe duplicate investigative sam ples as QC samples and RPD criteria from the D4 analytical SOPs were included in Tables 2-8 and 3-4 of the QAPP.

(2) Section 3.5.1.2 of the QAPP (Field Spikes) states "the RPD for each pair of field spikes will then be calculated by using the results of the spiked samples. The calculated %R and RPD will be compared to the target QC limits in Tables 2-8 and 3-4." EPA suggests adding the acceptance criterion for RPD between pairs of field spikes to these tables. Tables 2-8 and 3-4 of the QAPP were revised to include RPD criteria from the D4 analy tical SOPs for field spike duplicate QC samples. QAPP B4

B5

## (3) Overall the QAPP must clearly discuss acceptance criteria, DQO, criteria for rejecting data and corrective actions. Additional detail was added to the Section 2.7.2.2 of the QAPP to describe DQOs for the analyses and QC samples and to identify potential scenarios that may result in data being rejected. The following text was added to Section 5.3.1 of the QAPP to describe potential replacement of rejected data: “In the event that test data are rejected, the determination to replace rejected data will ultim ately

be made by

SEHSC and EPA based on the amount of usable data collected, the objectives of the study , and the number and ty pe of rejected data.”

Sections 2.9.7 and 5.3.2 of the QAPP were revised to include statements specifying that (1) rejected data, if any , would be described in the next Interim Report to EPA and in the data usability report to be included in the study’s Final Report, and (2) all data, including any rejected data, would be presented in the Final Report.

To aid in defining “normal operating conditions” for the W WT Ps, each site-specific sections was augm ented with a table showing the m inim um , average, and maximum annual values for parameters that could be analy zed within a short period (e.g., flow rate, ammonia, phosphorus, total suspended solids, dissolved oxygen, or pH) and that could be used by the W WT Ps to evaluate performance of the plants. In addition a new Call Log Form was added as Appendix G of the Study Plan Revision 1 to record the information obtained from the W WT Ps. Finally , additional text was added to Section 3.2 of the Study Plan to describe information obtained from the municipal W WT Ps as to how they

monitor and react to potential upsets. Detailed historical upset infomration was not provided by

the W WT P operators; however, operators who responded to the question about normal operating conditions indicated that they have not had an upset in several years. A list of some issues that can potentially cause upsets at W WT Ps is provided Section 3.2 of the Study Plan; they were also added to Section 2.6.2.2 (Schedule Constraints) of the QAPP for completeness. Sufficient info. is not provided in the QAPP regarding data quality

, acceptance criteria, use of data, and data limitations. EPA recommends addressing uncertainties surrounding how the team

## To help ensure river conditions are safe for performing sampling and not affected by weather conditions, the following text was added to QAPP Section 2.6.2.2: “River flow rates at the time of sampling will be compared to the 7Q10 flow, which is the lowest 7- day average flow that occurs (on average) once every 10 years. If the flow rate in the river im me diately

prior to or at the time of sampling is greater than the 7Q10 flow, ERM will evaluate the site conditions based on the nearest USGS station flow rate and contact the W WT P site contact to discuss safety

issues to determine if sampling can proceed. The information obtained will be documented in the Call Log Form, which is included in Appendix C of the Study Plan." This discussion will be added to Section 3-2 in the next submittal of the Study Plan.

River flow rate and water temperature are provided for each plant in the Study Plan's site-specific sections; in cases where a nearby USGS gauging station does not record river temperatures, averages of the local weather data were included in a table to allow an evaluation of whether the river may

be too cold to sample for biota. A new Table 3-1 with the 7Q10 flow (i.e., the lowest 7-day average flow that occurs on average once every 10 years), annual minimum, maximum, and average flow rates for each receiving river was prepared for use as a reference for the base flow rates. A reference to this table will be added to Section 3-2 of the Study Plan. (Note that the reference to Table 3-1 in Section 3.4 of the Study Plan Revision 1 will be corrected to reference Table 3-2 in the next submittal of the Study Plan.)

The following statement was added to Section X.2.3 of the Direct Discharge Study Plans to address potential abnormalities in equipment or operating conditions that might have an impact on D4 effluent concentrations: "ERM will call the site contact prior to mobilization of field crews to verify that the manufacturing/processing units that discharge wastewater containing D4 to the W WT P and the W WT P itself are functioning under normal operating conditions and flow rates. The basis for this determination will be recorded in a Call Log Form (Appendix G)."

For the Indirect Discharge W WT Ps, the following statement was added to Study Plan Sections X.2.3 to address potential impacts on D4 effluent concentrations: "ERM will also verify that the industrial plants that potentially discharge D4 are discharging to the W WT P. The basis for these determinations will be recorded in a Call Log Form (Appendix G).” recommends addressing uncertainties surrounding how the team will determ ine if the timing of a sampling event is acceptable, plant operations are "normal", and weather conditions are "ty pical". Please provide historical plant operation data, including process upsets for each plant. Please provide weather data for each plant . Please include a statement and sufficient supporting summary data to indicate what are considered "normal" plant operations.

“Samples shall be collected during normal plant operations and during such times that effluent flow rates from the wastewater treatment system are representative of the normal plant operations.” This need would be met if SEHSC submitted info. that both plant operations relevant to D4 were normal, effluent flow rates were representative preceding (by three days) and during the tim e of each sampling event. This could be accomplished by a succinct, written narrative of the associated process operations along w/ strictly

necessary

supporting process data. Any abnormal equipm ent or operating conditions that might have an impact on D4 effluent concentrations or flows should be clearly identified and explained. B9

## B10 Further details on the database software and how the electronically stored data will be transmitted to the participants is needed. A version number for the database software and a description of how it will m eet record keeping needs should be included in the QAPP. Section 3.10.4 of the QAPP was revised to provide additional detail about the EQuIS database, including information describing the database and software version numbers, the storage/archival of information, and the transmittal of information amongst the study participants. Database record storage and retention were already described and data archival and retrieval were already described in Sections 2.9.6 and 3.10.6 of the QAPP Revision 0, respectively

.

(1) EPA recommends including info. regarding how the assessment of compliance w/ the SOPs will be recorded (i.e., checklist or other recording mechanism). The checklists provided in App. J for each event do not have a place to indicate compliance w/ each of the SOP bullets; only compliance w/ SOP 102 and 30 are recorded in the checklist. EPA suggests adding the other SOPs to the checklist. There is no SOP 102; we have assumed that the comment refers to SOP 120. Appendix J of the original submission of the QAPP had two checklists for each matrix sampling SOP: one to check that all equipm ent and documentation has been procured (equipment and documentation checklist), and one to check that the sampling procedures have been followed as indicated in the SOP (procedural checklist). Appendix J of the QAPP has since been revised to include only procedural checklists, and checklists were added for non-sampling SOPs (#s 070, 080, 090, 200, 110, 120, and 130). Each procedural checklist has the individual activities listed in the corresponding SOP, plus space for checking off if the activity has been performed and for adding the initials of the person that is filling the checklist. To make it clearer, the SOP # was added to the Checklist's title.

(2) EPA recommends having a checklist for performing GLP audits prior to going into the field to ensure that audits are performed consistently

and to have documentation of this. The checklist should be included in the QAPP appendices and contain a description of expectations, similar to the info. provided in Tables 5- The recommended checklists have been added to the QAPP as Appendix K.

(3) Sect. 4.1.1.2 does not describe how an internal laboratory audit will be performed and what methods will be used to perform the audit. EPA suggests including a checklist of what systems will be audited as well as a description of the expectations, similar to the info. provided in Tables 5-1 and 5-2. The performance of internal laboratory audits is described in the Laboratory QAMs included in Appendices G and H to the QAPP. Laboratory checklists for internal audits have been added to these QAPP appendices. C1

## Although it's mentioned who communicates/reports to whom, it is not clear how ERM is going to provide project status reports (e.g.,

mo nthly reports or monthly

meetings). This info. should be included in this section.

EPA suggests adding the frequency

. Reports to the Study Director will be provided via e-mail at the frequencies specified in Section 4.1.1. Reports to the Sponsor's Project Manager will be provided monthly , also via e-mail. This information has been added to Sections 4.1 and 4.2 of the QAPP, as applicable. A new Section 4.2.2 was created to include the monthly QA reports.

EPA suggests specify ing who will prepare the docum ents and who will receive them in a table or list w/in the document. Table 4-1 was added and is now referenced in Section 4.2 of the QAPP. This table identifies QA reports along with the titles of preparer(s) and recipient(s), and the frequencies.

D1 EPA suggests adding a statement that specifies if analy tical data does not fall w/in the acceptance criteria, the data will be reported but flagged. The flags that will be used should be specified w/in the document. EPA also suggests including references to the table(s) that contain the acceptance criteria. Add discussion on corrections if min. sample size problems arise from rejected or destroyed samples. Sections 2.9.7 and 5.3.2 of the QAPP have been revised to include a statement that all data, including any

rejected data, will be presented in the Interim Progress Report and Final Report. Retain samples will be available in most cases for analysis in the case of lost samples or suspect data. It may

not be possible to collect the specified 100 grams of benthic organisms, therefore, the QAPP includes some flexibility to adjust sample size for primary and retain benthic organism samples. The minimum sample size is defined by the method detection limit and the lowest standard concentration, and the information has been included in Section 3.2.1.5 of the QAPP .

Section 5.2.2 of the QAPP has also been revised to specify that any QC samples that do not meet specifications will be noted and flagged; however, flags will not be assigned to sets of samples associated with the QC sample(s). There is no “acceptance criteria” for the analytical data, with the exception of the MPC that are specified in Table 2-8.

Finally , Section 5.2.2 of the QAPP has been revised to refer to a description of the flags that will be assigned by

the laboratory

or during the data usability assessment in Appendix L of QAPP Revision 1, which contains a list of the laboratories’ standard data qualifiers. C2

## Document **EPA Comment**  **# EPA**  **Comment SEHSC Response** 

Study Plan 1 Identification of D4 processor or formulator is not adequate. The ECA

(Appendix 2 - Environmental Testing for Indirect Discharge Sites, Pages 22-23) specified that all wastewater treatment sites selected for

mo nitoring must be currently processing wastewater from one or more industrial sites known to be a D4 processor or formulator as documented through industrial user surveys or by other readily

available information. The ECA also specifies that a description of the industrial activity at the D4 processor or formulator sites that indirectly discharge to the W astewater Treatment Plant (W WT P) sites shall be requested (and reported, if obtained) from D4 processor or formulator sites that are not controlled by signatory companies.

There is no information in SEHSC's submissions that fulfills these requirements. Specifically , EPA reviewed survey results for candidate WWT Ps which include: (1) identification of industrial facilities that discharge to each W WT P, along with their standard industrial classification (SIC) codes, (2) permitted wastewater flow to the W WT Ps, and (3) percent contribution of total wastewater flow to the W WT P. These surveys, however, do not provide confirmation that the industrial facilities' wastewater contains D4. W hile SIC codes may indicate the potential presence of D4, they

do not provide information, which shows that candidate W WT Ps submitted to fulfill the indirect discharge category are currently processing wastewater from one or more industrial sites known to be a D4 processor or formulator. In response to EPA’s Initial Comments on the Study Plan, a survey

is being conducted of certain indirect dischargers to the proposed W WT Ps to obtain further information on those sites’ D4 activities.

## 2 The sample collection procedures for benthic organisms (QAPP Section 3.2.1.5) are not consistent with the ECA. The ECA (Appendix * - Testing Standard for the Collection, Sample Handling, Transfer and Analysis of Biota Sam ples for D4, Figure 5, Page 50) specifies that a total mass of 100 grams should be collected. The QAPP, however, states "in the event that 100 grams of benthic organisms cannot be obtained, the absolute mi nim um mass of benthic organisms required is 25 grams." The agency

em phasizes, as discussed previously , that if the grab samples do not y ield sufficient sample mass, then the effort should be repeated in an adjacent location. Please revise the QAPP for consistency with the ECA. During the October 2014 field training event, only a few, small benthic organisms (less than 1 gram) were collected after repeatedly deploy ing the Ponar device. ERM consulted with ALS to determine the mi nim um sample size needed to run the analyses, which is 25 grams. SOP #040 was modified to indicate that several attempts to collect benthic organisms will be made with several different sampling devices at different locations, and that the decision to collect less than the 100 grams required in the ECA would be taken by the Study

Director given the efforts performed. There is no intention of just try ing once, one sampling device, or one location. The text of the QAPP will be modified to reflect the revised SOP #040, which includes the following procedures (emphasis added):

SOP #040, Section 4.4, Step 11: 11. W eigh the am ount of benthic organisms collected in the bottle. If biom ass is greater than 100 g, proceed to Step 21. If biomass is less than 100 g, repeat Steps 6 and 8 through 10 in the same or nearby area adjacent to the river sampling location defined by using the procedures in SOP #130 until a minimum of 100 g of benthic organisms have been collected. However, if an adequate mass of benthic invertebrates is not obtained in day one of sampling, then proceed to Step 12. During extended sampling periods, the benthic organisms in the intermediate stainless steel collection buckets or jars should be stored on ice to avoid decomposition of the collected benthic organisms

SOP #040, Section 4.4, Step 22: If after an extended sampling effort in which all reasonable alternate sampling devices have been attem pted and upon concurrence with the Study Director, less than 100 g but at least 25 g of benthic organism have been obtained, proceed to Step 24. “Extended sampling effort” shall be defined as deploy me nt of all applicable sampling devices when and if determined that the initially

selected method is ineffective. Otherwise, proceed to Step 23. If at least 25 g of benthic organisms have not been collected after the extended sampling effort, the Study Director will be contacted to discuss whether sampling should be continued or if incomplete or no benthic organisms samples will be submitted to the laboratory

.

## The following text was added to Section 5.3.1 to address the justification portion of the comment: "Any data outside the specified limits will be noted and evaluated/investigated as appropriate by the laboratory

PM/QAM and the ERM Analy tical Coordinator. Rejection of sample analy tical data will depend on all the instrument and QC/QA data available. The rationale for the decision to reject any data will be provided in the next Interim Report and in the Final Report."

Section 2.7.2.2 describes potential scenarios that may result in data rejection. In response to EPA QAPP Comment No. 3 (letter dated December 4, 2014) the following additional detail was added to the Section 2.7.2.2 of the QAPP to describe DQOs for the analyses and QC samples and to identify potential scenarios that may result in data being rejected:

## Example scenarios of issues that could be raised by field spike results and examples of the steps that would be taken to resolve each issue are as follow: Scenario A. Field spike recoveries meet accuracy MPC

• No action required Scenario B. Both field spikes are high, with recoveries above the accuracy MPC

• Check spike solution concentration (measured before and after field sampling)

• Check lab water, reference sediment, and rainbow trout field blanks for signs of D4 contamination Scenario C. Both field spikes are low, with recoveries below the accuracy MPC

• Check spike solution concentration

• Check recovery of matrix spike QC samples Scenario D. Field spikes are variable, precision MPC not met

• Check precision of lab water, reference sediment, and rainbow trout field blanks, matrix spikes, and analytical sample duplicates to determine if variability is widespread or limited to field spikes.

• Examine field notes to assess if any issues were observed during field spiking. The ultimate determination of data usability will include a review of all instrument performance, field QC, lab QA, and sample QC data. The data usability assessment process is described in Section 5.3.1. While a failure in field spike recovery or duplicate sample precision will not automatically result in data rejection, there are several potential scenarios that may result in data being rejected. These include:

• Gross contamination of field or laboratory blanks;

• No recovery or very low (less than 10%) recovery D4 spikes in field or laboratory QC samples;

• Evidence that field or laboratory procedures differed grossly from the SOPs included in the Study Plan and QAPP

• Missing raw data, incomplete test substance identification or control documentation, or failure to maintain and document sample or test substance custody.

The following text was added to Section 5.3.1 of the QAPP to describe potential replacement of rejected data: “In the event that test data are rejected, the determination to replace rejected data will ultim ately

be made by

SEHSC and EPA based on the amount of usable data collected, the objectives of the study , and the number and ty pe of rejected data.”

Sections 2.9.7 and 5.3.2 of the QAPP were also revised to include statements specifying that (1) Revision to the QAPP based on EPA Comment No. 3 (letter dated December 4, 2014) is not adequate. The QAPP does not include adequate detail to describe how and where rejected data will be reported by SEHSC to EPA. Any

rejected data needs to be described in a section of an interim or final report along with the justification, merely including it in the full data submission is not acceptable. Further criteria to describe if outlier data would be rejected needs to be included in the QAPP and who would m ake decisions regarding whether to reject data. 3

## 4 Revision to the QAPP based on EPA Comment No. 4 (letter dated December 4, 2014) is not adequate because it does not address EPA's comment. Further clarification on sample handling (QAPP Section 3.3.1.1) and D4 stability (QAPP Section 3.4.4) is needed. The QAPP indicates that stability

of D4 in properly

preserved samples ranges from 14 days to 18 weeks. However, the QAPP states, "to ensure that USEPA has time to review sample results prior to sample disposal, retain samples and primary

sample volume remaining after extraction will be disposed of 60 days after submittal of the Interim or Final Report that include the associated raw and summary data." In light of the D4 stability lim itations on sample viability , EPA m ust be given sufficient time to review the data. Procedures for timely communication with EPA need to be established and documented in the QAPP. The 18 weeks applies only to the biosolids; the rest of the matrices have shorter holding times. However, in response to this comment, SEHSC has authorized the extraction of the influent, effluent, and surface water retain samples to extend their holding time to at least 40 days. ERM/SEHSC will be obtaining data from ALS during summer 2015 on the stability of these extracts over periods of up to 90 days or more if needed. This stability data will be provided to EPA with the interim report submitted after the completion of the extract stability testing .

Consistent with the ECA, available results willl be reported to EPA in the interim progress reports. QAPP

## In general, 'headspace requirements' are for sample handling not analytical reasons. D4 has a very large Henry’

s Law Constant and will escape water and partition into air, unless there is a hydrophobic matrix in the water the D4 can partition into. Biota (fish and invertebrates) are hydrophobic and will retain D4; there is no reason to control headspace as long as sample container is sealed. Therefore, there are no special headspace requirements for biota.

Biosolids and sediment samples will be homogenized in the sample jars before aliquoting the individual analytical samples. There must be enough space in the jars so that the sediment is not spilled during the process. Although Sections 3.2.1.3 and 3.2.1.4 of the QAPP Revision 1 specify that jars for biosolids and sediments will be filled two-thirds full, SOPs 030 and 040 reflect the most recent decision of the team with respect to the sample volume for the solid matrices: approximately 20 grams per jar. Sections 3.2.1.3 and 3.2.1.4 of the QAPP will be modified to reflect the “approximately 20 grams per jar” in the next submittal.

All the water samples are extracted in the original sample jars, so sufficient room must be present to add the 10 mL of hexane/internal standard solution for the extraction. The LDPE squares are added to provide a hydrophobic matrix to which D4 will adsorb. This minimizes the loss/escape of the D4 into the headspace. Both the field SOPs (010 and 020) and Sections 3.2.1.1 and 3.2.1.2 of the QAPP Revision 1 specify that jars will be filled with approximately 50 mL +/- 10 mL sample (which is approximately half full for a 4-ounce sample jar). Revision to the QAPP based on deficiencies identified for Elements B2 and B4 of EPA's 2002 QAPP Guidance (letter dated December 4, 2014) is not adequate. Further clarification on the sample collection procedures for influent/effluent, surface water, biosolids, and sediment (QAPP Section 3.2.1.1 - 3.2.1.4) is needed. The QAPP states that sample jars will be filled only

two-thirds full or half full depending on the media sampled. Please clearly

describe how the volatility of D4 in relation to headspace within sam ple jars will be addressed. 5

## To provide further detail on this issue: headspace must be present in aqueous and biosolids/sediment sample jars to accommodate sample preparation at the laboratory . To address EPA's concerns about headspace in sample jars, QAPP Section 3.4.4 will be revised to describe how volatility of D4 is addressed within sample jars for aqueous, sediment, and biosolids samples. For aqueous samples, LDPE squares are added to provide a hydrophobic matrix to which D4 will adsorb. For sediment and biosolids, D4 will be partitioned into (hydrophobic) organic matter and would not volatilize into sample jar headspace. Evidence to support this is the recovery of field spikes within the 30% RPD.

QAPP Section 3.4.4 will also be revised to indicate that D4 stability in solvents after extraction is not affected by

headspace. Once the D4 is extracted into either the hexane or tetrahydrofuran solvents, it is stable and will not be lost in a closed container. There is also a stable isotope labeled D4 internal standard present to account for any analy te loss due to adsorption, evaporation, or other process.

6 Revision to the QAPP based on EPA Comment No. 5 (letter dated October 31, 2014) is not adequate. The sample collection procedures for fish (QAPP Section 3.2.1.6) are not consistent with the ECA. The ECA (Appendix * - Testing Standard for the Collection, Sample Handling, Transfer and Analysis of Biota Samples for D4, Page 52) specifies that two species of fish from different trophic guilds, if practicable, collected in sufficient mass such that individual or composite samples can be prepared for the analysis of D4, shall be selected. The ECA also specifies that if adequate quantities of fish from different trophic guilds are not available the two m ost abundant species will be selected. Please revise text in QAPP Section 3.2.1.6 for consistency with the ECA. The 2nd sentence of Section 3.2.1.6 of the QAPP will be replaced with the following quote from the ECA: "Two species of fish from different trophic guilds, if practicable, collected in sufficient mass such that individual or com posite samples can be prepared for the analysis of D4, shall be selected. If adequate quantities of fish from different trophic guilds are not available the two most abundant species will be selected." within sam ple jars will be addressed.

### 0900006481abfc51 - April 2, 2015 DRAFT

**Document EPA** 

**Comment #**  **EPA Comment SEHSC Response** 

1 1 **Duration Between Sampling Events**(Study Plan Section 3.2, Study Plan Sections 7.3 through 21.3 and QAPP Section 2.6.2.2.). There is no site-specific information on the sampling schedule included in the Study Plan or QAPP.

**ECA Requirement:** The ECA (Appendices 1-3) specifies that samples shall be taken during two testing events at least three months apart and that the exact duration between sampling events for each site shall be determined in a detailed Sampling Plan included in the Study Plan and QAPP.

Th e Study Plan provides optimal time frames for monitoring based on low river flow (low dilution) and safety concerns. The provided optimal time periods consist of a two month period (June and July) and a four month period (August through November). Monitoring within these ranges allows for possible durations less than three months as required by the ECA. For example, sampling in July and again in August would result in two testing events only one month apart.

1.1 Please revise the Study Plan and QAPP to include an overall sampling schedule which lists the proposed dates for each sampling event for each site and sampling location. All task dependencies should be identified and captured in the schedule (e.g., sampling team 1 requires X-days pre-/post-mobilization and cannot sample two sites simultaneously, and other dependencies such as sampling equipment, sampling platforms, holiday schedules, and laboratory capacity). A detailed evaluation of the appropriate windows for sampling the selected sites based on when typical (baseline) flows can be anticipated to be present, barring unusual weather events or other events requiring contingency planning, has been conducted. The projected schedule provides for two sampling events for each site, which will be separated by a minimum of 3 months. Sampling at the Friendly W WTP will be separated into a pre-July 15, 2015 sampling event and a Spring 2016 event because of their W WTP effluent diffuser construction project that starts by July 15, 2015 and is expected to be completed in October or November 2015 (see Study Plan Section 9.2.3).

A preliminary detailed schedule has been prepared and will be submitted in version 2 of the Study Plan. Sampling activities are projected to start the 2nd week of June, running until the end of November. Because of the potential for issues related to normal operating procedures and weather conditions, the planned schedule must be considered an estimate and remain flexible. Th at is why sample windows were identified in the Study Plan.

1.2 EPA recommends that the Study Plan and QAPP be revised to include a discussion of contingency plans in place (e.g., alternative sampling schedules that could be implemented if initial sampling conditions are not met). EPA suggests that contingency planning include developing alternative sampling schedules based on the assumption that plant operations, weather, or river conditions will preclude sampling as initially planned. EPA also suggests the inclusion of measures to be taken to minimize the potential for not achieving the required duration between sampling events (e.g., additional sampling teams, alternative laboratories), as well as the measures that will be taken if the sampling window will not be met. Th e Study Plan and QAPP will be revised to include a discussion of contingency planning-related measures, including : 1. Pre-visits at POTW facilities to ensure logistical issues are minimalized; 2. Pre-sampling conference calls with POTW operators to ensure the plant is operating under normal conditions and river conditions are appropriate for sampling; 3. Multiple sampling teams are assigned to ensure sampling schedule and to accomodate changes in schedule due to potential issues that would require a change in the schedule; 4. ALS Salt Lake City has been contracted and certified to serve as a back up lab to ALS Kelso. Preferably, all samples should be analytzed for D4 at one commercial testing program when the analysis occurs, unless there are unforseen circumstances such as lack of laboratory availability as noted in 40 C.F.R. Section 790.68(b)(2)(iii);

Sample windows were provided to specifically account for potential changes in sample schedule and to avoid the need to request schedule changes for every minor schedule change. An alternative detailed schedule could be provided to demonstrate how modifications to the schedule would still allow sampling to occur while keeping the required duration between sampling events. However, this would only be a conceptiual schedule given that potential issues impacting the schedule are unknown and would not likely become known unttil just prior to the scheduled event.

2 **Normal Plant Operations**(Study Plan Section 3.2, Study Plan Sections 7.2.3 through 21.2.3, QAPP Section 2.6.2.2 and QAPP Section 3.9). There is no site-specific documentation regarding the criteria or means that are used by the facilities to determine normal operating conditions in the Sampling Plans.

**ECA Requirement** : The ECA (Appendices 1-3) specifies that samples shall be collected during normal plant operations and during such times that effluent flow rates from the wastewater treatment system are representative of normal plant operations. Th e ECA (Appendices 4-8) also specifies that normal operating conditions will be established by consulting with the operator of each W WTP, indirect and direct discharge facility. Further, the ECA specifies that the criteria or means that are used by the facilities to determine normal operating conditions will be documented in the site-specific Sampling Plans and that confirmation will be obtained that the subject facility is operating under normal conditions prior to commencing sampling at a given location.



### 1 of 13

### 0900006481abfc51 - April 2, 2015 DRAFT

**Document EPA** 

**Comment #**  **EPA Comment SEHSC Response** 

2.1 EPA recommends that the normal plant operations discussion be revised to include the following list of plant operations that are not normal:

• Exceeding W WTP design capacity (i.e., hydraulic, organic, and solids loading capacities, as applicable); • Upsets, as defined by their discharge permits; • Bypasses, as defined by their discharge permits; • Utilizing emergency systems, as defined by their discharge permits; • Noncompliance with any permit requirements or conditions; and • Exceedance of any permit limits.

Each of these conditions should be defined for each plant, including discussion of how the conditions will be determined and how they will be documented during premobilization. For example, W WTP operators will provide plant design capacities, whiledischarge requirements, conditions, and limitations can be identified from the NPDES permit. These conditions and their predetermined status or threshold should be captured on site-specific data collection forms. These forms would be pre-populated with each plant’s design capacities and permit limits; yes/no checkboxes would be provided to record upset, bypass, and emergency conditions, as well as compliance with other permit conditions. ERM would complete the site-specific forms during the pre-mobilization call, including recording actual plant loadings and effluent quality on the form at the time of the call. In the case of conditions that require extended periods of time to assess (e.g., 5-day BOD testing), and in consideration of the hydraulic holding time of the treatment system and weather-induced variation, ERM should record conditions for several days prior to and including the day of the sampling event. As presecribed by the ECA, "Normal operating conditions will be established by consulting with the operator of each W WTP, indirect and direct discharbge facilitiy. Confirmation will be obtained that the subject facilitiy is operating under normal conditions prior to commecing sampling at a given location." No sampling will occur during upsets, bypasses, or use of emergency systems, as these conditions occur in cases of unusual weather conditions.

Study Plan Sections 7.2.3 through 21.2.3 will be modified to refer to the site-specific pre-mobilization data collection form. The pre-mobilization form will include request for confirmation that the facility is not experiencing any of the "not normal" conditions identified in EPA comment under 2.1, as well as a section to include any "other" plant operations that the POTWreports to be 'not normal."

To demonstrate compliance prior to mobilization, COD data will be requested. For W WTPs whose NPDES permit does not define upsets, bypasses, or use of emergency systems (e.g., Adrian, MI), these items will not be included in the data collection form.

2.2 EPA recommends the following process for collecting and analyzing plant operations data:

1 Section 3.2 of the Study Plan (revised to incorporate EPA review recommendations) lists conditions under which D4 process operations and W WTPs may not be operating under normal operating conditions. This listing will provide a starting point for developing site-specific operation conditions and for defining normal operations. Each plant would start by developing a matrix listing all the parameters listed in Section 3.2.

2 Each site would then determine whether or not each of the listed parameters is applicable/relevant to their site; they can also add new, site-specific conditions to the list as appropriate.

3 For each applicable parameter, the site would then determine whether the parameter can be assessed quantitatively or only qualitatively. For parameters that can be assessed quantitatively, the site would determine whether normal operations for that parameter are best represented by a threshold (e.g., permit limits, design capacity) or a range of normal operation (e.g., MLSS or SRT). Finally, for parameters with a range of normal operation, the site would perform a statistical analysis of historic monitoring data, calculating, for example, mean and standard deviation. For parameters lacking normal distribution, the site can propose an alternative statistical representation of the data.

4 Each site would then develop site-specific data collection forms. These forms would include the site-specific listing of applicable parameters. For parameters measured qualitatively, the form would include yes/no checkboxes for ERM to report the plant’s pre-mobilization operating condition as either normal or not normal, as determined by the plant operator. For parameters that can be measured quantitatively, the form would display the pre-determined summary statistics and also provide space for ERM to collect and record the plant’s current operating conditions.

5 The bottom of the data collection form would include space to provide a narrative discussion of any qualitative parameters recorded as “not normal,” and any quantitative parameters measured beyond their threshold or more outside of a predetermined statistical range. The narrative discussions should describe the operating condition of concern, provide the rationale for determining whether or not operation is normal, and describe the anticipated impact on effluent quality. The rationale for determining normal versus not normal operation will be developed in consultation with the W WTP operator (as required by the ECA), and in compliance with conditions identified as NOT considered normal operations discussed above. If the cause of the operating condition of concern is unknown, or the impact unclear, monitoring should be postponed. See response 2.1.

2.3 Additionally, the discussion of normal plant operations should extend beyond W WTP operations, focusing on activated sludge treatment. Revise this section to also address operating conditions at direct discharge sites, including D4 process operations and the types of wastewater treatment systems operated by these plants (i.e., chemical/physical treatment). This includes, for direct discharge sites, defining plant operations that are not normal, and listing items that indicate that plants may not be operating under normal operating conditions. See response 2.1.

3 **Representative D4 Release Rate**(Study Plan Sections 7.3 through 21.3). There is no sitespecific discussion on how the typical rate of release of D4 will be determined. **ECA Requirement:** Th e ECA (Appendices 1-3) specifies that samples shall be collected at a time when the rate of D4 release is expected to be representative of the typical rate of release of D4 for that site. To meet this requirement, EPA recommends the selection criteria that follow. Study Plan and QAPP



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3.1 Please revise the Study Plan (Sections 7.3 through 10.3) to demonstrate that the proposed sample collection schedule for direct discharge sites will meet the following criteria: 1 Confirmation that the processes that generate D4 process wastewater are currently operating and generating wastewater that is being fed to the W WTP; and 2 Confirmation that these processes have been operating and generating wastewater as typical during the period of time prior to pre-mobilization equal to or greater than the hydraulic residence time of the W WTP. 1. The pre-mobilization data collection forms discussed in response to Comment 2.1 will be revised to include a survey/checklist to confirm that the processes that generate D4 process wastewater are operating and generating wastewater that is being fed to the W WTP at the time of sampling. 2. The pre-mobilization data collection forms discussed in the response to Comment 2.1 will be referenced in these sections.

3.2 Please revise the Study Plan (Sections 11.3 through 20.3) to demonstrate that the proposed sample collection schedule for the non-industrial and indirect discharge wastewater treatment sites will meet the following criteria: 1 The potential sources of D4 (residential use and/or industrial use), and 2 The days and times these wastewater sources are expected to be received at the POTW (e.g., diurnal cycle and days/hours of industrial operations). For example, if D4 is expected in consumer personal care products (such as deodorants and shampoos), D4 release rates from consumers might be expected in the morning when most people shower (and accounting for hydraulic residence time of the collection system). 1. The Study Plan pre-mobilization data collection forms will be revised to include a checklist to confirm the potential sources of D4 (industrial use). 2. Neither SEHSC or any of the W WTPs h as enough information (i.e., diurnal patterns of D4concentrations in the influent) to determine the time when maximum D4 discharge from residential (nonmanufacturing) sources will arrive at the W WTP; in addition, the time to reach the W WTP will vary depending on the distance of the discharger to the W WTP. Th erefore, this iinformation cannot be incorporated into the Study Plan. 4 **Fish Sampling- Technical Issues**

4.1 Th e QAPP and Study Plan state that the techniques and recommendations for fish collection described in the ECA (i.e., USEPA 2003a (Section 7.0 Procedures, pp. 3-5) and Powell and W oodburn (2009, Sample Collection, p. 8)) were generally followed. However, several other fish collection techniques (gillnets, trap/hoop/Fyke nets, and angling) that were not described in the ECA are also described for possible use based on site-specific conditions. These other commonly used fish collection procedures were based on EPA guidance (Fish Field Sampling, Operating Procedure SESDPROC-512-R3, EPA Region 4, April 2011).

**ECA Requirement:** The ECA (Appendix 8) states: Th e exact method for collection of fish is a site-specific determination. During preparation of the site-specific Sampling Plans, the physical nature (e.g., width, depth, flow) of the receiving water will be determined and used to guide the selection of the appropriate method of sample collection. For each site, collection procedures will be based, as appropriate to the characterization of the receiving water, on USEPA (Section 7.0 Procedures, pp. 3-5) and Powell and W oodburn (2009, Sample Collection, p. 8). This guidance identifies two main types of fish collection methods for relatively shallow and slow moving water and gives direction on choice of method, general practices, and other considerations for the field work. For each site, the exact collection method for fish samples will be detailed in the site-specific Sampling Plans and QAPP.

EPA recommends that the SOP be revised to include a description of the parameters and conditions under which each type of fish collection method would be preferred at each site. In addition, it is recommended that documentation be provided by the field crew describing the fish collection method used and the supporting rationale. This clarification should be made throughout the QAPP and Study Plan. Wewill prepare an attachment to the SOP (in the form of a table or matrix) that will provide further information on how to determine the appropriate fish sampling techniques for a site. Before mobilizing to each W WTP, we will review local fishing guides or lists, and attempt to obtain information from local people to further narrow the options. This review will be documented in field data forms.

4.2 **Sample Collection Procedures – Fish.** Th e approach in the Study Plan and QAPP is inconsistent with the ECA requirements to focus first on collecting different trophic levels before collecting based on abundance (e.g., the study plans state throughout that the two most abundant species collected will be selected for analysis, and if practicable, they will represent two different trophic guilds). This needs to be modified throughout the QAPP and Study Plan.

**ECA requirement:** The ECA (Appendix 8) states: On the day of field sampling at a given site, fish shall be collected and sorted by species. The taxonomic identification of each fish species shall be noted. Two species of fish from different trophic guilds, if practicable, collected in sufficient mass such that individual or composite samples can be prepared for the analysis of D4, shall be selected. If adequate quantities of fish from different trophic guilds are not available the two most abundant species will be selected. Information about the life history of the two species selected shall be included in study reports. The individual fish will be measured for length and weight.

Th e QAPP must also address the QA/QC of the taxonomic determinations of the fish made in the field. The QAPP should prescribe procedures for the review to ensure the collected fish are accurately identified and classified. This review step should preferably be performed in the field such that fish collection can be reattempted immediately if needed. If this review step is not performed until the laboratory, reattempt of fish collection may be difficult. Weagree that the ECA is clear that the goal is to collect two species of different trophic guilds, and only if it is not practicable to do so would two species in the same trophic guild be submitted. W e will revise the language to make clear that the objective includes two trophic guilds wherever this is not clear.

Taxonomic identification of fish to species to species level will be done in the field. The field teams, which will include at least one person experienced in fish identification, sampling and handling, will have appropriate identification manuals for the local conditions. At most locations it is expected that the fish likely to be found in numbers to be considered as a potential target will be well known as to species characteristics and trophic level.

It is important to avoid excessive fish mortality. Fish species that will not be retained will be released immediately. To ensure this the procedures will be revised such that a determination will be done prior to sampling whether it is likely that collecting fish from two trophic guilds will be possible, as follows: Before mobilizing to each W WTP, we will make a site specific determination based on (a) available literature and references; (b) initial site observations by a competent person; and (c) local fishing guides, fish lists or information from local persons, regarding the most likely species to be encountered. If it is determined that fish from 2 separate trophic guilds are feasible, then set this as the objective and select the fish collection method based on that. If sufficient fish of different trophic guilds are expected to be absent, then collect the two most abundant species expected using the fish collection method most appropriate to achieve this goal.

Wo rding will be added to the QAPP Sections 3.2.1.6 and 3.9 and to SOP #060 regarding the procedures and QA/QC for the taxonomic determinations of the fish made in the field. 

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Our response to comment 2 of the March 9, 2015 comments addressed this question. The purpose of the language is to provide a contingency for the very likely situation that 100 g of benthic biomass simply are not available even after repeated sampling over a larger area. To reiterate, the response to Comment 2 of the March 9, 2015 comments indicated the following:

During the October 2014 field training event, only a few, small benthic organisms (less than 1 gram) were collected after repeatedly deploying the Ponar device. ERM consulted with ALS to determine the minimum sample siz

e needed to run the analyses, which is 25 grams. SOP #040 was modified to indicate that several attempts to collect benthic organisms will be made with several different sampling devices at different locations, and that the decision to collect less than the 100 grams required in the ECA would be taken by the Study Director given the efforts performed. There is no intention of just trying once, one sampling device, or one location. The text of the QAPP will be modified to reflect the revised SOP #040, which includes the following procedures (emphasis added):

SOP #040, Section 4.4, Step 11: 11. Weigh the amount of benthic organisms collected in the bottle. **If biomass is greater than 100 g, proceed to Step 21. If biomass is less than 100 g, repeat Steps 6**  **and 8 through 10 in the same or nearby area adjacent to the river sampling location defined by using the procedures in SOP #130 until a minimum of 100 g of benthic organisms have been**  **collected. However, if an adequate mass of benthic invertebrates is not obtained in day one of sampling, then proceed to Step 12.**  During extended sampling periods, the benthic organisms in the intermediate stainless steel collection buckets or jars should be stored on ice to avoid decomposition of the collected benthic organisms

SOP #040, Section 4.4, Step 22: **If after an extended sampling effort in which all reasonable alternate sampling devices**  have been attempted and upon concurrence with the Study Director, less than 100 g but at least 25 g of benthic organism have been obtained, proceed to Step 24. “Extended sampling effort” shall be defined as deployment of all applicable sampling devices when and if determined that the initially selected method is ineffective. Otherwise, proceed to Step 23. If at least 25 g of benthic organisms have not been collected after the extended sampling effort, the Study Director will be contacted to discuss whether sampling should be continued or if incomplete or no benthic organisms samples will be submitted to the laboratory.

5 **Site-Specific Sampling Plans - Direct Discharge Sites** Comments 5.1.1 and 5.1.2 within this section are ECA requirements that must be addressed. The remaining comments within this section (Comments 5.1.3 through 5.1.6) are considered technical deficiencies that should be addressed, unless previously identified as an ECA requirement (e.g. comments pertaining to “normal plant operations” must be addressed).

5.1.1 **Study Plan Sections 7.2.3 through 10.2.3.** Please revise to describe how each of the criteria and conditions listed in Study

Plan Section 3.2 will be evaluated specific to each site. Additionally, please develop site-specific call log forms for insertion into Study Plan Sections 7.2.3 through 10.2.3, listing each of these criteria and conditions and their predetermined range or threshold for acceptable sampling (i.e., normal plant operations, duration between sampling events, typical and unusual weather conditions, period since unusual weather, and representativeness of typical rates of release of D4). Sections 7.2.3 through 10.2.3 will be modified as requested, including the preparation of site-specific premobilization data collection forms, if the necessary data are available.

5.1.2 **Study Plan Sections 7.3 through 10.3.** Please revise to incorporate how an assessment of normal operating conditions will be

considered in determining sampling timing and schedule. Sections 7.3 through 10.3 will be revised to incorporate the consideration of normal operating conditions in determining sampling timing and schedule.

5.1.3 **Study Plan Sections 7.5 through 10.5 and Figures 7-1 through 10-1.** Please revise “Sampling Locations Description”

sections and “Site Location: figures to include greater detail. Figures 7-1 through 10-1 were provided to show a perspective of the proposed location for the river samples. One or more photos of the river were provided in Figures 7-6 through 10-6; however, because the specific location where the river will be sampled will not be defined until the day of sampling, more detail of the area of the river where the samples will be collected cannot be provided in advance.

5.1.4 **Study Plan Figures 7-2 through 10-2.** Please revise “W astewater Treatment Plant Process Flow Diagram” figures to clearly

indicate sampling and flow measurement locations. Th e sampling and flow measurement locations will be added to the "W astewater Process Flow Diagram" Figures 7-2 through 10-2.

5.1.5 **Study Plan Section 9.2.2 and Figure 9-2.** The “W astewater Treatment Plant Process Flow Diagram” figure appears to show

primary clarifiers following neutralization and before equalization; however, this treatment step is not included in the “W WTP Process Description” section. Please correct this oversight. Section 9.2.2 in the February 2, 2015 Study Plan indicates: "Process wastewater, sanitary wastewater, and dewatering from sludge removal activities are directed to a two-stage neutralization pit for pH adjustment. Wa stewater is then sent through two primary clarifiers where oil and solids are removed and then into the equalization basin where it is mixed." Therefore, no modification is necessary.

5.1.6 **Study Plan Section 10.2.2 and Figure 10-2.** Th e “Wastewater Treatment Plant Process Flow Diagram” figure remains largely

illegible, but appears to show primary clarification between the oil/water separator and the air stripper; however, this treatment step is not included in the “W WTP Process Description” section. Additionally, the chemical precipitation and flocculationsedimentation treatment steps included in the “W WTP Process Description” section do not appear to be included in the indicated “W astewater Treatment Plant Process Flow Diagram” figure. Please correct this oversight. Study Plan Section 10.2.2 will be modified to reflect Figure 10-2.

6 **Site-Specific Sampling Plans - Non-Industrial and Indirect Discharge Sites** 4.3 **Sample Collection Procedures – Benthic Organisms**(QAPP Section 3.2.1.5). The QAPP states, “in the event that 100 grams of benthic organisms cannot be obtained, the absolute minimum mass of benthic organisms required is 25 grams.

**ECA Requirement:** Th e ECA (Appendix 8, Figure 5) specifies that a total mass off 100 grams of benthic organisms should be collected.

EPA emphasizes, as discussed previously, that if grab does not yield sufficient sample mass, then the effort should be repeated in an adjacent location. Please revise the Study Plan and QAPP as appropriate.



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6.1.1 **Study Plan Sections 11.5 through 21.5, Figures 11-1 through 21-1 and Figures 11-2 through 21-2.** The “Sampling

Locations Description” sections and “Site Location” figures lack sufficient detail. Please revise text and figures as appropriate. Additionally, please revise the “Process Flow Diagram” figure for each site to clearly indicate sampling and flow measurement locations. Sections 11.5 through 21.5 will be revised to reflect any information on the sampling locations based on these April 2, 2015 EPA comments.

Figures 11-1 through 21-1 were provided to show a perspective of the proposed location for the river samples. One or more photos of the river were provided in Figures 11-6 through 21-6; however, because the specific location where the river will be sampled won't be defined until the day of sampling, more detail of the area of the river where the samples will be collected cannot be provided in advance.

Th e sampling and flow measurement locations will be added to the "Process Flow Diagram" Figures 11-2 through 21-2.

6.1.2 **Study Plan Sections 11.3 through 21.3.** Please revise the “Sampling Timing and Schedule” section to incorporate how

assessment of “Normal Operating Conditions” will be considered in determining sampling timing and schedule. Study Plan Sections 11.3 through 21.3 will be modified to incorporate how assessment of "Normal Operating Conditions" (as described in the response to Comment 2) will be considered in determining sampling timing and schedule.

6.1.3 **Study Plan Sections 11.2.3 through 21.2.3.** Several of the selected W WTPs are served by combined sewage systems with

permitted combined sewer overflows (CSOs). For these W WTPs, please revise “Normal Operating Conditions” sections to describe the combined sewage systems, the CSOs, and the historical frequency, extent, and conditions of CSO discharges (e.g., intensity and duration of precipitation events). Describe the fate and transport of discharges from known and likely D4 industrial users under CSO discharge conditions. Describe the criteria that will be used to determine whether and under what conditions periods of CSO discharges will be considered normal operating conditions. Furthermore, for indirect discharge WWTPs (Stu dy Plan Sections 17.2.3 through 21.2.3), describe the criteria that will be used to determine that the W WTP influentshall reasonably be expected to contain D4. Describe how these conditions and determinations will be documented during premobilization. If sampling is conducted conditions of CSO discharges, describe how these conditions (extent and nature) will be documented in the field notes and final report. Periods of CSO overflows will not be considered normal operating conditions, as they happen only in case of heavy rains that result in influent flow rates that exceed the hydraulic capacity of the W WTP. Th erefore, the requested information will not be provided; instead, the site-specific pre-mobilization data collection form discussed in the response to Comment 2 will include a checkbox to mark if the W WTP is having CSO overflows.

6.1.4 **Study Plan Sections 11.2.3 through 21.2.3.** Certain of the selected W WTPs h ave treatment system bypasses used during

emergency conditions. Please revise the “Normal Operating Conditions” section to indicate that use of these bypasses is notconsidered normal operating conditions. Additionally, please describe how these conditions will be documented during premobilization. Emergency conditions are not considered normal operating conditions. The site-specific pre-mobilization data collection form discussed in the response to Comment 2 will include a checkbox to mark if the W WTP is having treatment system bypasses.

6.1.5 **Study Plan Tables 12-2, 15-2, 16-2, and 18-2.** Please confirm whether historical monitoring data provided is for BOD5 or

CBOD5 and revise tables as appropriate. Tables 12-2, 15-2, 16-2, and 18-2 do show CBOD5 data; the tables will be revised to reflect this. The rest of the tables X-2 will be reviewed to ensure it reflects whether the parameter is BOD5 or CBOD5.

6.1.6 **Study Plan Section 11.2.2.** Please revise the “W WTP Process Description” section to describe the Emergency/Polishing Pond

and its historical frequency, extent, and conditions of use. Describe the criteria that will be used to determine whether and under what conditions use of the pond will be considered normal operating conditions. If sampling is conducted during use of the pond, describe how these conditions (extent and nature) will be documented in the field notes and final report, and how flows to and/or from the pond will be accounted for when reporting the influent and effluent flow rates. A description of the Emergency/Polishing Pond and its operation will be obtained from the W WTP and provided in Section 11.2.2. If the Emergency/Polishing Pond is being used, the plant will be considered not to be operating under normal conditions. Information about the historical frequency and extent of use is, therefore, not relevant.

6.1.7 **Study Plan Figure 11-2.** Please provide a replacement “Process Flow Diagram” as tank volumes and other small text are not

discernible. Even though the tank volumes and other small text are not critical for the purposes of the Study Plan, a new figure will be provided if available from the W WTP.

6.1.8 **Study Plan Section 12.2.2.** Please revise the “W WTP Process Description” section to provide additional information regarding

the planned addition of an external carbon dosing facility (e.g., chemical/source name, construction dates, date dosage is scheduled to commence). Information regarding the planned addition of an external carbon dosing facility (e.g., chemical name, construction dates, date dosage is scheduled to commence) will be obtained from the W WTP and added to Section 12.2.2. The source name is not considered relevant.

6.1.9 **Study Plan Section 12.0, Appendix I** . Boulder’s discharge permit indicates that flow measurement occurs only at the

wastewater influent. Please describe how effluent flow will be measured or estimated. As indicated on Page 3 of the NPDES permit: "For this facility, a single flow recording device is provided and is located at the point of inflow to the treatment facility. Since effluent flows will not be significantly different from influent flows, the single flow measurement device will be used for the recording and reporting of both influent and effluent flows. Reported influent flows will be used to monitor compliance with the effluent flow limitation." This information will be added to Section 12.0.

6.1.10 **Study Plan Section 13.2.3.** Please revise the “Normal Operating Conditions” section to provide additional information regarding

the planned biosolids loading facility and cogeneration engines (e.g., construction and implementation dates) and the anticipated “short-duration interruptions” (e.g., interruption of the entire W WTP only sludge management) and their impacts on sampling. Information regarding the planned biosolids loading facility and cogeneration engines (e.g., construction and implementation dates) and the anticipated "short-duration interruptions" (e.g., interruption of the entire WWTP or only sludge management) and their impacts on sampling will be obtained from the W WTP and provided in Section 13.5.

6.1.11 **Study Plan Section 13.5.** Please revise the “Sampling Locations Description” section to clarify whether the effluent sampling

location is before or after chlorination/dechlorination. Additionally, please discuss the representativeness of the selected biosolids sampling location, as Study Plan Section 13.5 indicates samples will be collected as the biosolids exit the belt filter presses, while Study Plan Section 13.2.2 and Figure 13-2, “Process Flow Diagram” describe that digested sludge is dewatered via centrifuges or belt filter presses. After further discussion with the W WTP, Section 13.5 will be modified to clarify whether the effluent sampling location is before or after chlorination/dechlorination and the representativeness of the sampling location for the biosolids.

6.1.12 **Study Plan Section 14.0, Appendix I.** Please revise Appendix I to include this W WTP’s discharge permit. Th e NPDES permit for Lexington, KY, which is in draft form, will be added to Appendix I of the Study Plan.

6.1.13 **Study Plan Section 14.2.3.** Please revise the “Normal Operating Conditions” section to provide additional information,

regarding the planned centrifuge dewater system and polymer change (e.g., installation/construction and implementation dates, does the polymer contain D4). Information about the planned centrifuge dewatering system and polymer change (e.g., installation/construction and implementation dates, does the polymer contain D4) will be obtained from the WWTP an d provided in Section 14.2.3. 

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6.1.14 **Study Plan Section 16.2.2 and Figure 16-2.** Sludge thickening using dissolved air floatation is discussed within the “W WTP

Process Description” section but is not included in the “Process Flow Diagram” figure. Additionally, flocculation is not discussed in the “W WTP Process Description” section but is present on the “Process Flow Diagram” figure. Please revise the text and figure as appropriate. Th e discrepancies between Section 16.2.2 and Figure 16-2 will be clarified with the W WTP and modifications made as necessary.

In addition, as indicated by the W WTP operator after completion of the Study Plan Revision 1, Sections 16.2.2, 16.5, and 16.6 will be modified to indicate that the biosolids samples will be collected from the sand drying bed that is closest to the time when it will be emptied. Sand drying beds are used for dewatering during the expected sampling time period (approximately May through October).

6.1.15 **Study Plan Section 17.2.2.** Please revise the “W WTP Process Description” section to describe the “high strength” wastewater

sources and their management, including the use and objectives of the “BAR” treatment unit indicated on Figure 17-2. Additionally, please revise text to discuss sludge thickening using the rotary drum thickener. Th e high strength wastewater sources and their management, and the use and objectives of the "BAR" treatment unit indicated on Figure 17-2 will be obtained from the W WTP and provided in Section 17.2.2.

6.1.16 **Study Plan Section 17.2.2.** The narrative is inconsistent regarding the use of polymers. Text within the “W WTP Process

Description” section states “Polymers are not used at the W WTP.... No information is available on the presence of siloxanes in the polymers used at the W WTP.” Also, Study Plan Section 17.5 mentions “the polymer tank room.” Please address this oversight. Section 17.2.2 will be modified to clarify whether polymers are used after clarifying the issue with the WWTP.

6.1.17 **Study Plan Section 17.5.** Th e description of the biosolids sampling location is unclear. Please clarify what is meant by the “post

belt processing machine.” A clarification of what is meant by the "post belt processing machine" will be provided in Section 17.5 after discussion with the W WTP.

6.1.18 **Study Plan section 18.1 and Table 18-2.** Th ere is a discrepancy in the reported 2013 average flow (65.7 MGD v.s. 71.96).

Please correct this oversight. Section 18.1 will be modified to indicate the correct 2013 average flow of 71.96 MGD.

6.1.19 **Study Plan Section 18.5.** Please revise the “Sampling Locations Description” section to better describe the effluent and

biosolids sampling locations. Section 18.5 will be revised to better describe the effluent and biosolids sampling locations.

6.1.20 **Study Plan Section 19.1 and Appendix I** . The “Site Description” section describes a design average flow rate of 32 and 40

MGD for dry and wet conditions, respectively. However, the discharge permit specifies a design average flow rate of 54 MGD. Please revise the text as appropriate. Section 19.1 will be revised as necessary, after clarification is obtained from the W WTP. Note that, based on Page 5 of 13 of the W ichita W WTP discharge permit, the flow of 54 MGD is the minimum flow at which discharge of effluent from the Extraneous Flow Basin at Plant 1 will be allowed; it's not indicated in the permit as a design average flow rate.

6.1.21 **Study Plan Section 19.9.2 and Figure 19-2.** The text states “sludge that settles in the intermediate...clarifiers is returned to the

tricking filters...”; however, the process flow diagram shows that sludge from the intermediate clarifiers is returned to the bar screens. Please correct this oversight and revise text and figure as appropriate. Section 19.9.2 will be modified to indicate that the sludge that settles in the intermediate clarifiers is returned to the bar screens.

6.1.22 **Study Plan Section 21.0, Appendix I.** Please revise Appendix I to include this W WTP’s discharge permit. Th e NPDES permit for Chicago, IL was included in Appendix I of the Study Plan submitted on February 2, 2015; it starts on page 1778 of the Adobe Acrobat file.

6.1.23 **Study Plan Section 21.2.2, Study Plan Section 21.5 and Figure 21-2.** Th e “Process Flow Diagram” figure depicts and the

“WWTP Process Description” section describes that digested sludge is dewatered via centrifuges or lagoons, while text within the “Sampling Locations Description” section specifies that samples will be collected as the biosolids exit the post-digestion centrifuges. Please revise text and figure to discuss the representativeness of the selected biosolids sampling location. As clarified by the W WTP operator after completion of the Study Plan, Sections 21.2.2, 21.5, and 21.6 will be modified to indicate that the biosolids samples will be collected from the lagoon that is closest to the time when it will be emptied. Lagoons are used for dewatering during the expected sampling time period (approximately May through October).

7 **Pre-Mobilization Information Collection Logs (Study Plan Appendix G)**

7.1 EPA recommends that site-specific call logs for the direct, indirect and non-industrial sites be developed based upon comments above for Study Plan Sections 7 through 21. The site-specific call logs for indirect and non-industrial discharge sites will record both influent and effluent flows, while the logs for the direct discharge sites will only record effluent flows. Appendix G of the Study Plan provides an example call log form. See the responses to Comments 2.1. Site-specific pre-mobilization data collection forms will be prepared and added to Appendix G.

7.2 **Study Plan Appendix G (Pre-Mobilization Information Collection Logs) for Direct Discharger WWTP #DD1, Adrian, MI.** Th e call log form for this direct discharger should record flows for both Outfall 001A (process wastewater discharge compliance point) and Outfall 001B (treated ground water); daily flow measurements at these outfalls are required by the plant’s NPDES permit. The plant’s call log form should also indicate whether “High-Strength W astewater” is being routed to the W WTP at the time of sampling and during the period of time prior to pre-mobilization equal to or greater than the hydraulic residence time of the W WTP. Th e treated ground water is discharged to the W WTP h eadworks, and its concentrations will be reflected in the samples collected at Outfall 001A. Therefore, no sampling of Outfall 001B will be performed.

Th e plant's pre-mobilization data collection forms will include whether high-strength wastewater is being discharged to the W WTP at the time of sampling and during the period of time prior to pre-mobilization equal to or greater than the hydraulic residence time.

7.3 **Study Plan Appendix G (Pre-Mobilization Information Collection Logs) for Direct Discharger WWTP #DD2, Carrollton, KY.**  The call log form for this direct discharger should record flows at the time of sampling for both Outfall 001 (compliance point) and Outfall 002 (internal compliance point); continuous flow measurements at these outfalls are required by the plant’s NPDES permit. Continuous flow measurements at these outfalls are completed as required by the plant’s NPDES permit and recorded measurements can be provided at or around the time of sampling.

8 **QAPP Project Staff Reporting Requirements and Additional Quality Control Related Issues**

8.1.1 **QAPP Section 2.4.** Descriptions of the how communications and any reporting relationships between the ERM QA Unit and the

ALS QA Managers will be handled are needed in the QAPP. The signoff or approval trail of project QA and management personnel indicating that the data generated are appropriate for use needs to be documented. For example, it is stated in the body of the QAPP that the ERM Data QA Manager will communicate with the ALS quality staff, but that communication is not reflected in Figure 1-1. Further, the independence of the ALS QA Unit Managers with those ALS staff working directly on the project analyses needs to be documented. Communications and reporting between the QAU and the laboratory are described in QAPP Section 4.1.2.3. This communication pathway will be added to Figure 1-1 in the next QAPP submittal.

Th e procedures and personnel responsibilities for verifying that data are usable are described in QAPP Sections 5.2 and 5.3. The body of the QAPP does not state anywhere that the ERM Data QA Manager will communicate with the laboratory; QAPP Table 2-3 and the body of the QAPP state that the ERM Analytical Coordinator will be the point of contact with the analytical contract labs.

Th e next QAPP submittal will include the following statement in Section 2.4.2: "The ERM and ALS QA Managers will be independent from staff working directly on the project sampling and analyses. "



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8.1.2 **QAPP Section 2.8.2.** Th e QAPP states that the validation study will be repeated at ALS/SLC in early 2015. Please provide

validation results for ALS Salt Lake City. Th e validation study for ALS/SLC has not been completed yet; the laboratory estimates it will be completed in early summer 2015. The validation study results will be included in the third Interim Progress Report and in Appendix C of the next QAPP submittal.

8.1.3 **QAPP Section 2.9.3 and Appendix D.** It is stated that a description of the EQUIS EDD format will be provided in Appendix D.

Th is Appendix only contains a listing of several data elements. There is no description of the format of all data elements that will be submitted to EPA. Please provide this information. Th e EDD template in Appendix D identifies all of the "data elements" that will be reported by the laboratory for each analytical result. The next QAPP submittal will include an accompanying reference table identifying the format (text, numeric, date, etc.) and allowable values, when applicable, for each EDD element. The information that will be submitted to EPA is described in QAPP Section 2.9.7.

8.1.4 **QAPP Section 3.5 and Appendix F.** Corrective Actions for sample QC failure are not defined in the QAPP, analytical SOPs in

Appendix F, Section 14 of all analytical SOPs, and Section 13 for SOP OE-DC-LIPIDS. The SOPs mention that if QC fails, Nonconformity and Corrective Action Reports (NCAR) are required and routine corrective actions are part of normal operating procedures and no other documentation (other than laboratory or maintenance logs) are necessary. If there are known routine corrective actions that are part of the operating procedures, they are not mentioned in the SOPs, which is where this type of information should be located. For example, if a CCV percent recovery fails, it is common practice that samples that are bracketed within a passing CCV and a failing CCV are re-analyzed. If CCVs continue to fail, the instrument can undergo a cleaning or maintenance cycle or the CCV solution can be re-prepared.

Please revise the SOPs to include guidance as to what is routinely done when a QC fails and if there are different steps for different failed QC samples. This is to ensure that the laboratory will re-analyze samples if QC fails or if they flag samples and what they commonly do in such occasions. Additionally, please include corrective action procedures for all types of QC in case of failure, such as IS, CCVs, Blanks, field spikes and surrogates, hold times, and anything that has acceptance criteria. Th e next QAPP submittal will include a table that (1) provides guidance as to what is routinely done when a QC fails, and (2) includes corrective action procedures for all types of QC in case of failure.

9 **Method Validation Study – Vial Headspace**(QAPP Section 3.4.3 and Appendix C). The QAPP states that D4 analytical SOPs were prepared for the water matrices, solid matrices and tissue samples. EPA expects clarification of the issues surrounding headspace in sample vials that were expressed in the March 9, 2015 letter. Specifically, it is expected that SEHSC will revise the Study Plan and QAPP to include an explanation (and relevant documentation)of how the analytical techniques will account for the headspace.

**ECA Requirement:** Th e ECA (Appendix 4) specifies that the commercial laboratory will develop a method for analyzing D4 that shall be adapted from the analytical method specified in Knoerr (2013). The ECA further specifies:

Th e Knoerr (2013) analytical method utilizes pieces of LDPE film to act as a sorbent and partial barrier to prevent loss of analyte to the headspace of the sample container. Immediately after collection, a water sample is placed into a container containing pieces of LDPE, which adsorbs the D4. In the laboratory, the water sample and the LDPE sorbent are solvent extracted and processed for analysis with GC-MS. Headspace must be present in aqueous and biosolids/sediment sample jars to accommodate sample preparation at the laboratory. To address EPA's concerns about headspace in sample jars, QAPP Section 3.4.4 will be revised to describe how volatility of D4 is addressed within sample jars for aqueous, sediment, and biosolids samples. All the water samples are extracted in the original sample jars, so sufficient room

mu st be present to add the 10 mL of hexane/internal standard solution for the extraction. The LDPE squares are added to provide a hydrophobic matrix to which D4 will adsorb. This minimizes the loss/escape of the D4 into the headspace and is consistent with the Knoerr 2013 report referenced in ECA Appendices 4 and 5.

Biosolids and sediment samples will be homogenized in the sample jars before aliquoting the individual analytical samples. There must be enough space in the jars so that the sediment is not spilled during the process. For sediment and biosolids, D4 will partition into (hydrophobic) organic matter that would minimize D4 volatilization into sample jar headspace. Retention of D4 by sediment/biosolids matrices will be demonstrated by field spike recoveries. In order to minimize the amount of headspace while still allowing room for homogenization/aliquoting, and to be consistent with the February 2, 2015 QAPP and Study Plan documents, the next submittal of SOPs #030 and #040 will specify that sample jars for biosolids and sediments will be filled 2/3 full.

Biota (fish and invertebrates) are hydrophobic and will retain D4; there is no reason to control headspace as long as the sample container is sealed. Therefore, there are no special headspace requirements for biota.

QAPP Section 3.4.4 will also be revised to indicate that D4 stability in solvents after extraction is not affected by headspace. Once the D4 is extracted into either the hexane or tetrahydrofuran solvents, it is stable and will not be lost in a closed container. There is also a stable isotope labeled D4 internal standard present to account for any analyte loss due to adsorption, evaporation, or other process.

10 **QAPP Appendix C-2 – Technical Issues**

10.1 Th e method validation reports fail to provide the date and time of analysis following sample preparation. W ere the samples analyzed immediately after preparation, or did the study authors use a holding time that would mimic the actual holding times that would be experienced when field samples are taken?

10.2 Suggest adding to all validation reports in Appendix C2 a summary of quality control sample results and passing criteria, such as Internal Standard (IS) added to samples not just in calibration curve, field spike (if it was added), pre/post-extraction spiked surrogates, and blanks.

10.3 Validation Reports are vague on how each calibration point was obtained. The validation reports should provide the weight of standard (the actual not just target weight).

10.4 Provide an example of the sequence including calibration, QC samples, and blanks in the order these are analyzed in SOPs or Reports. 

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10.5 Define what is a long sequence and when multiple Procedural Blanks (PBs) between samples are required.

• Provide number of PBs analyzed and analysis position in the sequence. • Suggest analyzing PBs at the end of each sequence.

10.6 Provide volume of extracted sample poured into autosampler vial. A large sample was prepared and 50 mL were used for each sample, but how much of each sample was poured into the autosampler vials?

10.7 Provide date and time, and volume of solution and vial for the following:

• Prepared bulk sample • Individual 50 mL samples (only volume was provided) • Autosampler vials ready for analysis

10.8 Recommend that a set of samples is analyzed the same day of preparation and another set should be analyzed after a period of time that equals the amount of days that real samples will be from collection to analysis. 10.9 Provide date and time of sample analysis. 10.10 Provide calibration standards and QC samples preparation date and expiration date. 10.11 Provide total run time.

11 **Mixing Zone Modeling** (Study Plan Section 2.5.6 and Appendix F) Comments in this section are based upon the following **ECA requirements:** 

1. Samples are to be collected from the receiving water environment (i.e., surface water, sediment, and benthic) at a location as near to the outfall as is possible after “adequate” mixing of the discharge plume and ambient flow has occurred.

2. Monitoring shall not occur within three days of an unusual weather event, such as heavy rain storm. Thus, receiving water flows used in the modeling effort should be consistent with typical dry weather flows for the time of year in which monitoring will

occur.
11.1 **Summary Comments**

11.1.1 Th e Study Plan fails to provide justification for applying the 100-meter downstream sampling location to the direct discharge,

non-industrial and indirect discharge wastewater treatment plant sites. Th e selection of the 100-m downstream sampling location should be considered a point of departure for the evaluation. A key consideration when considering sampling for sediment and biota is the observation that these media are indicators of long-term exposures. It is also evident that effluent plume behavior is highly sensitive to flow differences, and the point of complete vertical mixing required under the ECA may have large spatial variability (as the CORMIX results suggest). Therefore, there is no single point of complete vertical mixing that would be truly representative of exposure. On this basis, the 100 m was chosen as a reasonable starting point for an exposed benthic population considering the increasing probability of additional sources of D4 further downstream and the flow-dependent plume variability.

11.1.2 EPA recommends that “adequate mixing” be evaluated on the basis of complete vertical mixing unless modeling produces

unreliable or unfeasible results. Tracer studies should be considered for sites if modeling is inapplicable.

ECA Requirement: The ECA (Appendix 8) specifies:

At each site, benthic organisms shall be collected as close as reasonably possible to the effluent outfall provided adequate mixing of the discharge and receiving water has occurred and where adequate benthic organism sample masses are obtained. Each site specific sampling plan will identify where the effluent and receiving stream are adequately mixed and the basis for the determination . At each site fish, surface water and sediment shall also be collected at approximately the same location. A rationale was provided in the Study Plan for the 100 m distance in the discussion of the modeling and investigations conducted for the direct discharge sites and measures to identify/confirm location of plume for sampling, including tracer dyes, were noted in SOP 130. The CORMIX modeling showed complete vertical mixing before the proposed 100 m distance sampling location for only the Adrian, MI and Carrollton, KY direct discharge (DD) W WTPs, n ot for all DD W WTP's. The Friendly, W V plant had a minimum distance of 407 m before vertical mixing was complete, and the W aterford, NY plant effluent wasn't completely mixed with the receiving water until a minimum distance of 3.1 km (see Table 2-5 of the Study Plan). If the effluent plume determination method outlined in SOP 130 identifies that the effluent is completely mixed at the 100 meter distance (i.e., not visually identifiable either with or without dye and the conductance/temperature profile fails to detect an effluent plume), a sample distance of 50 meters downstream of the effluent discharge point will be established as the sampling location. As noted in the Study Plan, two of the W WTP sites have defined mixing zones – Gresham, OR: 61 m and Boulder, CO: 70 meter (field-confirmed) and 132 meter (regulatory).

A vertical mixing monitoring or modeling study is beyond the scope of this ECA monitoring program Th e information required in these comments will be added to the method validation reports for the next submittal.



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11.1.3 Th e Study Plan does not provide adequate details on the modeling inputs and the rationale for the chosen values for the direct

discharge sites. Modeling inputs are listed in the tables of each section in Appendix F. - Adrian, MI site: pg. 77, “predictions of mixing were made using EPA’s (CORMIX) and best estimates of realistic conditions (see Appendix F.1).” - Carrollton, KY: see Appendix F.2 - Friendly, W V: see Appendix F.3 - Waterford, NY: see Appendix F.4 Information such as the discharge structures dimensions and orientation, effluent flow rates, effluent temperatures, and effluent densities were determined from client provided data and site visits. River widths and channel appearance were determined from Google Earth aerial imagery. River water depths, velocities, and flow rates were determined from site visits, USGS and NOAA data.

11.1.4 Wh ile the choice of 100 m for the direct discharge sites appears more appropriate than the other two approaches proposed by

the Study Plan (constant dilution factor and complete mixing), this distance may result in more dilution than is necessary and may be inconsistent with the goals of the ECA. See response 11.1.2.

11.1.5 Monitoring at multiple distances downstream could compensate to some degree for the uncertainty of determining when mixing

has reached the benthic layer. Th e inclusion of two additional downstream sampling locations may confound the results due to the influx of other water and chemicals along the rivers where the DD W WTPs discharge. This may also esult in different methods or analysis (e.g., sample compositing or averaging) being used for the DD sites than are used at other sites. Therefore, this change has not been incorporated into the Study Plan.

11.2 **Dilution Summary and Recommendation**

11.2.1 As stated above in Summary Comment 9.1.2, EPA recommends that “adequate mixing” be evaluated on the basis of complete

vertical mixing unless modeling produces unreliable or unfeasible results (i.e., sampling location on the order of kilometers downstream). In instances where modeling is inappropriate, due to channel geometry or other confounding factors, mixing should be evaluated using field studies and best professional judgment. See response 11.1.2.

11.2.2 EPA cannot make recommendations regarding the non-industrial and indirect discharge wastewater treatment plant (W WTP)

sites based on information presented in Study Plan Section 2.5.6.2, as no modeling was performed or data reported for these sites.

EPA recommends that either modeling and/or field studies be completed for the nonindustrial and indirect discharge W WTP sites. Dilution modeling is site-specific. Mixing zone simulations performed for the direct discharge (DD) sites are not applicable to the non-industrial and indirect discharge W WTP sites described in the Study Plan, unless there is a high degree of correspondence between the discharges and receiving water bodies. See response 11.1.2.

11.3 **General Comments**

11.3.1 As stated above in Comment 9.1.2 and Comment 9.2.1, “adequate mixing” should include vertical mixing consideration. To fully

characterize and evaluate the resulting exposure of aquatic and sediment dwelling organisms, the sampling location should ensure sediment dwelling organisms are exposed to the effluent plume. For the intent of the ECA Testing Program, EPA recommends that “adequate mixing” be defined at or beyond the point of complete vertical mixing unless it violates another part of the Study Plan. Other considerations may be applicable, and should be discussed within the Site-Specific Sampling Plans. See response 11.1.2.

11.3.2 Benthic organisms’ exposure to the discharge will be limited until the spreading line of the plume reaches a riverbed. Exposure

will be maximized once complete vertical mixing has occurred. For three of the four direct discharge facilities (#DD1-Adrian, #DD2-Carrollton, and #DD4-W aterford), the Study Plan assumes an equal effluent density to receiving water density and discharges occur at the surface of the receiving water, which is likely to indicate these effluent will mix in the vertical at a slow rate. For #DD3-Friendly, the effluent is buoyant and discharged from a submerged single point outfall located just above the bottom of the stream which will tend to produce rapid vertical mixing rates. Th e Study Plan assumes effluent water temperatures are equal to receiving water temperatures for three of the four direct discharge facilities (Adrian, Carrollton, and W aterford). The Study Plan also assumes that effluent constituents have a negligible influence on effluent density, and therefore the effluent density is equal to the receiving water density. At Friendly, W V, the effluent temperature is greater than the receiving water temperature, and the effluent density is less than the receiving water density.

Th e comment indicates that slow mixing occurs for the case of equal effluent and receiving water densities and for submerged, buoyant discharges; however in both these cases other processes (e.g., turbulent mixing, entrainment for high velocity discharges) may alter these results.

11.3.3 Th e Study Plan defines dilution factor as the ratio of ambient receiving water to effluent flow in the plume at the location of

interest (Study Plan Section 2.5.1.2, page 32). The Cormix User Manual uses a slightly different definition of dilution, which differs from the Study Plan definition by one unit (i.e., Study Plan Dilution = Cormix Dilution – 1). The Study Plan does not explicitly state that they have corrected for this difference in the Study Plan. Th e Study Plan presents dilution results per the CORMIX definition, i.e., dilution, S is (total volume) / (volume of effluent) where total volume = volume of ambient water + volume of effluent.

11.3.4 Th e Study Plan does not specify whether centerline dilution (i.e., peak concentration at a downstream distance) or flux-averaged

dilution (i.e., average concentration at downstream distance) is being specified. At any given downstream location, the centerline dilution would be more stringent than (i.e., less than) the flux-averaged dilution. Please refer to Figure 11-1 for further illustration. Outside of the jet region of the plume, Cormix calculates flux-averaged dilution so this is likely to be the value presented in the Study Plan since the distances being discussed are hundreds to thousands of meters downstream. [ **The image provided in**  **the comment could not be copied here.** ] Results are presented as the centerline dilution at various distances downstream of the outfall.



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11.4 **Study Plan Section 2.5.6**

Th e Study Plan asserts that it is necessary to identify the mixing zone for each W WTP and direct discharge effluent discharge to be sampled, and that the availability of well-defined mixing zones, such as those established in an NPDES permit, was determined during site visits.

Ty pical mixing zones established in NPDES permits are not optimal for purposes of characterizing average, long-term exposure in the receiving water environment. Regulatory mixing zones in permits are typically based on reasonable worst-case conditions applicable to acute and/or chronic conditions with reoccurrence intervals corresponding to water quality standards (for instance, 1-day out of three year returns). The use of regulatory mixing zones may not be consistent with “normal operations” or typical dry weather receiving water flows specified within the ECA. See response 11.1.2.

11.5 **Study Plan Section 2.5.6.1**

11.5.1 Th e Study Plan asserts that the inputs to the model were based on best estimates of realistic conditions of the river at each

facility and various flow rates. Limited rationale is provided for the modeling inputs, and we were unable to substantiate the use of many of the individual model inputs (for further discussion on inputs, please refer to Section 9.6). This conclusion is based upon a review of Study Plan Section 2.5.6, Study Plan Section 7.0, Study Plan Section 10.0 and Appendix F. See the response to Comment 11.1.3.

Th e Study Plan states that model output was evaluated to develop a consistent approach to determine the zone of “adequate” mixing for all DD sites. The Study Plan explores three approaches:

1. Complete mixing – Complete mixing is defined by the Study Plan in Appendix F as “where the plume is uniform both vertically and horizontally throughout the river cross-section.” Modeling estimates show complete mixing did not occur within 100 km downstream under any of the modeled river flow rates for the #DD2-Carrollton facility, nor for the highest modeled river flow rate for the #DD3-Friendly facility. The distance to complete mixing for the #DD4-W aterford facility exceeded 3 km.

At the distances required for complete mixing, the Study Plan finds that several other contributing sources (both point source discharges and tributary inflow) to the rivers occur between the outfall and the complete mixing distance. These additional contributing sources introduce confounding effects that cannot be overcome. The Study Plan concludes that in order to have consistency between sites and to help ensure that sampling is not conducted too close to the effluent outfall or too far downstream, the distance to complete mixing could not be used as the point of adequate mixing.

EPA agrees that the long distances necessary for complete mixing are inappropriate for the purpose and intent of the ECA Testing Program. Additionally, the available dilution factors associated with complete mixing exceed 100:1 (i.e., the ratio of receiving water to effluent), and are not consistent with “low dilution” as specified within the ECA Testing Program.

2. Constant dilution factor – The Study Plan proposes the consideration of a constant dilution factor to determine the point of “adequate mixing”. The Study Plan points out that the #DD4-W aterford facility did not achieve a dilution of 10 until just past 150 m from the discharge point at the lowest modeled river flow rate, while the #DD1-Adrian facility was predicted to achieve a dilution factor of 10 in just 2.4 m. The Study Plan asserts that at a distance of 2.4 m the receiving water will be mostly effluent which, since it is in direct contravention of the modeled estimate, indicates a lack of faith in the reliability of the modeling results.

Th e Study Plan does not provide rationale for why they find a distance of 150 m too far away and leaves the assertion unsubstantiated. However, EPA agrees with the Study Plan’s conclusion based on the requirements of the ECA that the monitoring location be as close to the effluent outfall as possible, and that unnecessary dilution be minimized.
See response 11.1.2. 11.5.2 

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Based on the Study Plan’s modeling results for the #DD1-Adrian facility, at a distance of 2.4 m downstream of the effluent outfall, the receiving water is expected to be mostly receiving water (i.e., a dilution factor of 11:1). Based on the model, the assertion that the receiving water will be mostly effluent is unsubstantiated and unlikely. This was the Study Plan’s sole rationale for discounting the constant dilution factor approach, and is further referenced as rationale for supporting the third and chosen approach.

Performing monitoring based on a constant dilution factor, irrespective of the behavior of the effluent plume and the exposure to target organisms, is not consistent with the intent of the ECA Testing Program. The use of a constant dilution factor may result in monitoring locations where benthic organisms are not exposed to the effluent plume. Thus, we agree that the use of a consistent dilution factor is inappropriate for determining adequate mixing.

3. Use of a constant distance (100 m) - The approach eventually accepted by the Study Plan to define “adequate” mixing was the use of a constant distance of 100 m downstream of the effluent outfall. The chosen approach seems to rely on three claims: a. No other discharges to the receiving rivers were identified within 100 m of any of the direct discharge W WTP sites. b. This distance was neither too close to the facilities effluent (as would be the case if a specific dilution factor were used) or too far away (as would be the case if complete mixing were used). c. The other two options (complete mixing and constant dilution factor) have been determined to be inadequate.

Th at there are no other discharges to the receiving rivers within 100 m of any of the direct discharge W WTP sites is an important consideration but is not sufficient in and of itself to define adequate mixing. The Study Plan does not discuss the appropriateness of the approach in regards to collecting data adequate to address the purpose and intent of the ECA Testing Program. Specifically, whether benthic organisms are exposed to the effluent plume within 100 m of the effluent outfall and whether the effluent diluted more than reasonably necessary at 100 m. Adequate mixing must be defined and evaluated consistent with the purposes and intent of the ECA. Identification of a sampling location consistent with purposes and intent of the ECA should result in a sampling location where benthic organisms are exposed to the effluent plume and should not result in significantly more dilution than necessary at that location.

11.6 **Study Plan Section 2.5.6.2**

11.6.1 Th e Study Plan states that because of difficulties encountered during modeling of the selected DD facilities, and the lack of

correspondence between the predicted and actual location of the plume at a field training site (#DD2-Carrollton facility), the mixing zone for the municipal POTW s were not modeled. Instead, the same 100 m downstream distance is proposed as the potential sampling location for all sites.

Th e lack of correspondence between the modeling results and the field observations at the #DD2-Carrollton facility may indicate inappropriate input values were used in the modeling effort or that an incorrect Cormix module was used. The Study Plan should provide further discussion regarding the difficulties encountered and explanation for the lack of correspondence between the modeling results and the field observations. At a minimum, the Study Plan should evaluate and document whether effluent and receiving water conditions were representative of model inputs on the date field observations were made.

Additional discussion should be given to explaining the infeasibility of resolving the identified issues with the modeling effort. For instance, could field testing be used to calibrate the Cormix simulation and, if not, why is this standard technique inappropriate or infeasible in this instance? See response 11.1.2.

11.6.2 For the non-industrial and indirect discharge W WTP sites that were not subject to dilution modeling, it is not ideal to assume

monitoring at 100 m downstream of the effluent outfall is adequate for the purposes and intent of the ECA Testing Program. Wi thout additional data to evaluate the effluent plume, there is no supporting evidence to suggest that benthic organisms are exposed to the effluent plume at 100 m at each of the facilities. Mixing processes are site-specific. The downstream distance need to reach complete vertical mixing at one site will have no bearing on another site. W ith the direct discharge facilities, sitespecific modeling data indicated that vertical mixing had occurred prior to the sampling location, but there is no evidence to support such a finding for the remaining facilities.

However, due to cost considerations, it may be practical to assume vertical mixing has occurred within a given receiving stream at a downstream distance of 100 m if the following holds: • The receiving water to effluent flow ratio is low when compared to the DD facilities; • Stream depths are consistent with the characteristics of the DD facilities receiving streams; and • The effluent is not excessively buoyant. Th e CORMIX modeling showed complete vertical mixing before the proposed 100 m distance sampling location for only the Adrian, MI and Carrollton, KY direct discharge (DD) W WTPs, n ot for all DD W WTP's. Th e Friendly, W V plant had a minimum distance of 407 m before vertical mixing was complete, and the Wa terford, NY plant effluent wasn't completely mixed with the receiving water until a minimum distance of 3.1 km (see Table 2-5 of the Study Plan). See response 11.1.2. 11.5.2



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11.6.3 For the non-industrial and indirect discharge W WTP sites that were not modeled, the Study Plan does not provide information

regarding the presence or absence of additional point sources or non-trivial tributary flows into the 100 m downstream mixing intervals. If additional point sources or tributary inflows are identified between the effluent outfall and the receiving water monitoring location, the potential impacts of those point sources should be evaluated.

EPA concludes that due to the lack of data and analysis provided within the report for the non-industrial and indirect discharge WWTP sites, it is not possible to evaluate consistency with the ECA Testing Program requirements that facilities be selected with low dilution, and that the receiving water location be located as close as possible to the effluent outfall where adequate mixing occurs. Th e presence of additional point sources or non-trivial tributary flows (if any) downstream of the outfall up to the proposed 100 m distance sampling location will be evaluated and provided in the Study Plan.

11.7 **Appendix F**

11.7.1 Model Selection– The author does not indicate which Cormix module is utilized for each modeling effort. Th e following modules were utilized: Adrian, MI - CORMIX3; Carrollton, KY - CORMIX3; Friendly, W V - CORMIX1; W aterford, NY - CORMIX1.

11.7.1.1 Cormix1 should be used in instances where the discharge is emitted from a single port diffuser (either submerged or plunging),

which has a substantial jet or momentum component into flowing unstratified or stratified receiving water environments. Facilities that appear applicable based on Appendix F summaries: Friendly, W V [ **The image provided in the comment could not be copied here.**  ] See Response 11.7.1. CORMIX1 was used for the calculations at Friendly, W V

11.7.1.2 Cormix2 should be used with submerged multiport diffusers under the same general characteristics as CORMIX1. This model

does not appear to be applicable any of the four facilities described in Appendix F. Agreed. See Response 11.7.1.

11.7.1.3 Cormix3 should be used when an effluent enters a larger water body laterally, through a canal, channel, or near-surface pipe

without a substantial jet component and is also positively or neutrally buoyant. Facilities that appear applicable based on Appendix F summaries: Adrian, MI Site; Carrollton, KY; W aterford, NY. [ **The image provided in the comment could not be copied here.**  ] See Response 11.7.1. For W aterford, CORMIX1 was selected based on the configuration of the discharge - the discharge appears to flow overland to the Hudson River which was interpreted as a plunging flow. CORMIX3 is a possible alternative.

11.7.2 Effluent and Receiving W ater Flow Inputs – Selected flow inputs used in the modeling, broadly speaking, should reflect the issue

under investigation. For instance, when investigating acute mixing conditions, flow inputs should typically be based on a reasonable, worst-case scenario (i.e., high effluent flow rates and low/dry-weather receiving water flow rates). W hen investigating average long-term exposure (as is the case under this ECA), inputs should be based on long-term averages (i.e., average dry weather effluent flow rate and median/harmonic mean/geometric mean receiving water flow rates). Section 2.5.6.1 of the Study Plan states that inputs to the model were based on best estimates of realistic conditions of the river at each W WTP and various flow rates. However, it is unclear from Section 2.5.6.1 and the Appendix F memos how effluent and receiving water inputs were selected. For instance, were the effluent flow inputs developed based on an analysis of flow data and, if so, what was the analysis and why are the selected flows appropriate?

For the Carrollton facility, the receiving water high flow inputs represent the 90th percentile of the daily mean flow rates; this is inconsistent with the W aterford facility where the 80th percentile of daily flow rates was used. Low and high flows are undefined for the Adrian and Friendly facilities. The Study Plan should define the ranges of acceptable receiving water flows, and provide the rationale for the asserted ranges in regards to the intent of the ECA Testing Program.

We re effluent flow inputs based on design capacities or some other assumed value? If inputs are not to be based on averages or typical values, input parameters could also be selected such that they roughly approximate typical seasonal conditions anticipated during the period in which sampling is anticipated to occur. The ECA requires the monitoring occur at least 3 days following unusual weather, thus dry weather receiving water flows would be most appropriate.

Appendix F should provide the rationale to support each of the individual modeling inputs for the intended purposes of investigating “normal” operating conditions and typical dry weather stream flow. A single flow rate was used to define the effluent. CORMIX results will not be used to define the sampling location and will be removed from the Study Plan.

Ambient flows at Adrian, MI are for the 10th, 25th, 50th, and 90th percentile flows for the River Raisin. At Friendly, W V, ambient flows of 166m3/s, 231m3/s, and 1300m3/s are 1%, 2%, and 58% flows. The 10th, 80th, and 90th percentiles were utilized to show a range of low and high river flow conditions at each site.

11.7.3 Stream Geometry – The Cormix models assume fairly regular channel geometries, which are unrealistic over the distances (i.e., kilometers) discussed in the Study Plan. In winding streams and river, Cormix will produce more accurate results within the nearfield (i.e., dozens of meters downstream) than in the farfield (hundreds of meters downstream). In channels with many interruptions (i.e., sandbars) near the discharge location, modeled estimates of mixing are unlikely to produce reliable estimates of mixing. Model limitations in the far-field are discussed in the Results section of the W aterford, NY site in Appendix F.

11.7.4 Disjunction Between Modeled Plume Location And Field Observed Location– The modeling efforts will provide reasonable

estimates of plume location under circumstances where inputs are similar to conditions on the day of sampling. It is rarely the case that models and reality correspond cleanly. Given the incomplete and limited mixing predicted by the models and the irregularity of some channels described, use of a tracer test to confirm the sampling location is within the influence of the discharge at each site is recommended. Wh ile it is unlikely that modeling results will cleanly correspond to the realistic conditions at the time of sampling, it is useful to model the plumes to illustrate the plume behavior (bank attached, rising or falling, width versus river width, etc.) so that one can know what to expect during a tracer test.

12 **Overview of EPA’s QAPP Review and Approval Process**

12.1.1 QAPPs document the what, how, where, why and when of a project in addition to noting the specific QA system that governs the

project and the quality control activities that have been put in to place to detect, manage and correct actions that need fixing. QAPPs reflect the current state of the project and are designed to accommodate the need to change procedures during the course of the study, if warranted. QAPPs are living documents that are kept current over the conduct of the study. No response needed



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**Comment #**  **EPA Comment SEHSC Response** 

12.1.2 It is critical that those who will approve the QAPP understand the process that will be followed to make changes to study

protocols. In many cases minor changes can be made during the conduct of the work (with the needed approvals) and then are reported in interim and final reports. Major changes must be documented and approved by those who approved the original (or previous revision) QAPP before the change is implemented. In some cases such changes can be approved via phone or email in real time, following up with the appropriate documentation and signatures. No modification to the QAPP is required to respond to this comment. The process for modifying the Study Plan and QAPP is described in QAPP Section 2.9.5, and Document Control is described in QAPP Section 2.9.1.

12.1.3 Th e implementation of QAPPs follows a change process that ensures that users of the QAPP are aware of the changes made in

real time, and clearly when a new revision is issued and approved. Revisions in this context generally reflect major changes to study protocols for data collection, analysis, use and reporting. These changes are reported in a Revision History that accompanies the QAPP. The Revision History documents the change(s) made, the reason for the change and where the change was made in the document (via the page number). This allow users to quickly learn of changes made, to track them, and to easily locate the revised text in the document. One approach often used when revised QAPPs are sent to the project team for review and specifically to those who will approve the QAPP is to provide a “Markup” copy of the QAPP, in addition to the “Clean” version. New signature pages documenting that all signers of the QAPP have reviewed and approved of the changes are also prepared. A Revision History form will be included in the next QAPP submittal. The Revision History Form will also be described in QAPP Section 2.9.1, Document Control. Consistent with Comment 12.1.4, the first entry in the Revision History Form, Rev 0, will be for the first version of the QAPP approved by the EPA. The Revision History Form will therefore remain blank until EPA approves the QAPP.

12.1.4 Th e first version of a QAPP is often submitted for review several times before it is approved. The first version of an approved

QAPP is documented as Revision 0. After each revision is approved, the Revision Number increases by one. For this reason, the QAPP that is currently under review will be considered Revision 0 once it is approved by EPA. Th e QAPP and Study Plan will be modified to address this comment. The first version of the approved Study Plan and QAPP will be Revision 0. For document control purposes, the next revised QAPP and Study Plan submittals will be identified as "Version 3" or "V3".

12.1.5 Further details are needed describing how EPA will be informed in a timely manner on significant quality control issues that arise

during the conduct of the project activities and that require corrective actions that deviate from procedures that are documented in the QAPP. No modification to the QAPP is required to respond to this comment. Procedures for managing and documenting deviations from the field and analytical SOPs, including notification to EPA, are described in QAPP Sections 3.2.1.7 and 3.4.2, respectively. Consistent with the ECA, available results will be reported to EPA in the interim progress reports. 

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