Responses to review comments received for the external Se WQG draft dated September 2012.

Transcription

1 Responses to review comments received for the external Se WQG draft dated September Source (Name) Affiliation Page/Line Comment # Comment Mark Vancook Walter Energy General 1 I have reviewed the proposed changes to the T-Se guideline and was curious if comment you could provide some insight into the significance of the alert concentration that is being proposed for aquatic life at a level of 1 ppb? This concentration is very low (roughly 2x the analytical detection limit of many certified labs which may bring into question the reliability of T-Se readings at this concentration) and is close to baseline in some areas of the province. If you could provide some clarity as to what is the basis/intent for the proposed imposition of an alert concentration and how is it expected to be monitored/regulated by the MoE with respect to industry I would appreciate it. Bruce Ott AMEC General comment 2 Given the overwhelming amount of evidence that Se water concentrations in lotic environments of 50 micrograms/l have no effects on fish it is indeed disappointing the MOE chooses to ignore these data and instead sticks with the old guideline and in fact adds an alert guideline at half that concentration, thus guaranteeing that mining companies in BC will be all chasing a selenium ghost. Response See revised Introduction and Section 8.4.1, which provides the rationale for inclusion of an alert concentration and how we envision it would be used. Based on bioaccumulation models for sites in BC, there are situations (primarily lentic but also lotic ecosystems) where a water concentration of ~2 µg/l may not provide adequate protection from Se bioaccumulation and negative impacts to all sensitive species. The rationale and intent has been made clearer in the document. Most labs have low-level analytical capabilities for metals which typically have MDLs for Se of 0.05 µg/l, or better. An MDL of 0.05 µg/l is the MDL investigators should strive for to generate accurate data in ecological studies particularly for background sites. This is discussed in Section 9. Please see examples provided in pages Section for summary of literature for fish and other organisms reporting adverse effects linked with water Se concentrations less than 50 µg/l, and in some cases less than the guideline of 2 µg/l. Diet is the primary route but the dynamics of bioaccumulation are key to adverse effects in aquatic life. While some species might not be affected at extremely high levels of Se (50 µg/l), other more sensitive species would be extirpated at these levels. BC MoE protects all ecosystems, lotic and lentic and the most sensitive species and life stages. Les McDonald Spirogyra Scientific Consulting 156/ Given the move by other jurisdictions, notably the USEPA to move to a tissuebased guideline it is disappointing that MOE chooses to continue to promote a water chemistry based guideline with proven lack of applicability to the real world. It would appear MOE prefers professional judgement to science. 115/16 4 One point I would like to make relates to a publication by Hamilton and Palace (2001), which you have cited under section Chronic Toxicity Thresholds of Selenium (p. 115, line 16).The guideline TA only cites this publication once as an example of the lack of consensus as to what concentration of Se in environmental media is protective of sensitive receptors. I think it only fair that if you cite Hamilton and Palace (2001) you should also cite our rebuttal Please refer to the discussion at the beginning of Section 8.4, and in Sections and regarding rationale for water and tissue guidelines, respectively. BC MoE incorporated a suite of aquatic life Se WQGs which include water, sediment, dietary (invertebrate tissue), fish tissue (whole-body, muscle and egg) and bird egg tissue. The document discusses in many sections that tissue is a more direct measure of exposure. However, the water column guideline may be used as a surrogate for tissue and can be effective if site-specific bioaccumulation relationships have been established. The water alert and guideline concentrations are meant to provide flexibility in monitoring where tissue collection is limited or prohibited. Water guidelines do not preclude the use of tissue guidelines, they are meant to augment them. BC MoE has had a whole-body fish tissue guideline in place since Consistent with the approach the US EPA has chosen, the purpose is to provide an alternative to tissue sampling in circumstances where it may be difficult or prohibited. A reference to McDonald and Kennedy (2002) was added to the section. 1

2 (McDonald and Kennedy, 2002) which was published in SETAC Globe Learned Discourse, July-August 2002 issue. You can find it here: e39492ea8d220ccc9eefde51fc3f. Lee Harding Sciwrite 5 While it is generally true, and experts do agree, that most Se is taken up through the food chain and is mediated by detritus-based food webs that promote methylation, Harding (2008) gave evidence that under certain high oxic conditions and high selenate:selenite ratios, selenium can be taken up directly from the water column, rather than from bacterially methylated forms of selenium via the food web. This arose from our Red-winged Blackbird study, in which one of the lentic environments produced anomalous results in terms of its high effects on reproduction, relative to the other marshes. This was a marsh in name only. A large settling pond, it was almost all open water with emergent vegetation only at one end, where the blackbirds nested. Two streams tumbled down from active mining areas, highly oxygenated, and the water column throughout was clear to the bottom, and was generally 2 3 m deep. We had a devil of a time getting mud for sediment analysis there wasn t any, even in the emergent-vegetation zone. The substrate was all gravel, or coal. The redox potential and other physical and chemical measurements were typical of a lotic environment. The invertebrates that the blackbirds were feeding to their nestlings had higher Se than would have been expected from the total aqueous Se, and the nestlings had higher mortality also. The Discussion in my paper reviews this issue. By the way, the perennially high Se levels in Spotted Sandpipers and marginally lower levels in American Dippers living near coal mines should have told us years ago that the lentic-methylation-food web paradigm should be taken with a grain of salt. 6 Why are my papers categorized as secondary literature sources? Maybe this is defined differently, but I usually think of original field and lab experiments (which mine were) as primary, whereas review articles, like many of those you categorized as primary are secondary, in that they don t produce new data, but merely review and integrate the data of others. This may appear to be merely semantic, but as the only guy who has actually measured effects of selenium on reproduction in birds in BC, I would prefer it to be given higher credence. 7 Christy Morrisey and colleagues had half a dozen interesting papers on American Dippers and selenium and other metals, e.g., Morrissey, C. A., L. I. Bendell-Young, and J. E. Elliott Linking contaminant profiles to the diet and breeding location of American dippers using stable isotopes. Journal of Applied Ecology 41: Great work! you and Russo put a lot of effort and thought into this and it shows. Thank you for pointing out this information. Harding (2008) was reviewed in the development of the guideline. There are examples of areas with unusual Se accumulation dynamics and this is one such example. This issue is discussed in Section 8.4. Studies were re-evaluated according to our protocol (MOE 2012, available on-line at ). All studies using field-collected gametes were classified as unacceptable. Field studies cannot be classified as primary or secondary because: 1) the exposure is not controlled (cannot be measured) throughout the exposure period and, 2) effects may be confounded by other co-contaminants. In spite of this, these studies provide extremely valuable information and were considered as part of the weight of evidence in the derivation of the BC Se WQG. The review articles you are referring to were a re-analysis of primary data (labgenerated or controlled feeding studies) hence the classification remained primary. Thank you. We added egg Se data from Morrissey et al. (2004) to Section , and reviewed, but did not use, Morrissey et al. (2005). Thank you. Guy Gilron Cdn Industry Selenium General comment 9 The BCMOE methodology for deriving provincial guidelines for the protection of aquatic life is based on the most sensitive endpoint for the most sensitive We used BC s protocol for developing water quality guidelines ( BC does not use the 2

3 Working Group (North American Metals Council) life stage of the most sensitive species tested. This differs from the national guideline derivation approach endorsed and advocated by the Canadian Council of Ministers of the Environment (CCME) and most other international jurisdictions which utilize the Species Sensitivity Distribution (SSD) approach. The SSD approach employs widely-accepted statistical techniques to derive scientifically-defensible water and sediment quality thresholds, which are based on all available toxicity data.[1] SSD approach to derive WQGs. The SSD paradigm is not consistent with BC s policies i.e., protecting the most sensitive species and sensitive life stage indefinitely. Also note that bioaccumulation is not considered to be part of the protocol for the derivation of CWQGs-PAL, as the protocol deals with the concentration of substances in the water column and the toxic effects resulting from direct exposure. See CCME Protocol for the Derivation of WQGs for the Protection of Aquatic Life 2007: General comment General comment 10 The CISWG recently commissioned a study to determine how a Canadian selenium guideline, using the CCME approach, would be derived. Using the SSD approach, the tissue (egg/ovary) guideline for fish would be 20 µg/g dry weight.2 This study resulted in a peer-reviewed publication in a premier international journal on environmental risk assessment (Integrated Environmental Assessment and Management).We refer you to DeForest et al. (2012).[2] A copy of the summary from this paper is also attached for your reference. 11 The current proposed draft BC selenium egg/ovary value of 11 µg/g dry weight was derived by applying a safety factor of 2 to the concentrations of µg/g dry weight in fish egg-ovary already established to be the no-observedeffect-concentration (NOEC) range for fish in BC. With a non-science based safety factor of 2, the new egg/ovary tissue guideline of 11 µg/g dry weight places even some fish found in reference waters at or above this concentration (e.g., Rudolph et al. 2008;[3] DeForest 2009;[4] McDonald et al. 2010[5]). We would like to alert you that setting overly-conservative selenium guidelines, which do not provide any greater protection to the environment, will have disproportionately higher impacts on industry support of jobs in BC. Specific DeForest et al. (2012) was reviewed in the process of developing the Se WQG, is mentioned in Section , and listed in the references. The SSD paradigm is not consistent with BC s policies i.e., protecting the most sensitive species and sensitive life stage indefinitely. Also note that bioaccumulation is not considered to be part of the protocol for the derivation of CWQGs-PAL, as the protocol deals with the concentration of substances in the water column and the toxic effects resulting from direct exposure. See CCME Protocol for the Derivation of WQGs for the Protection of Aquatic Life 2007: Also note that a disclaimer was added to the DeForest et al. (2012) paper stating that neither CCME nor Environment Canada were consulted or directly involved with the derivation of the guideline presented for consideration within this manuscript. The µg/g egg Se concentration represents the EC10 effect level (see table 8.13). We followed BC s protocol for developing water quality guidelines ( The guideline acknowledges that some background tissue Se concentrations from some tissue types or species may be naturally elevated. In areas where true background fish tissue Se concentrations exceed the guideline, site-specific water quality objectives may be considered in consultation the Environmental [1] Zajdlik & Associates Inc Statistical Analysis of the SSD Approach for Development of Canadian Water Quality Guidelines. Project # Canadian Council of Ministers of the Environment, pp. [2] DeForest, DK, Gilron, G, Armstrong, SA, and Robertson, EL Species sensitivity distribution evaluation for selenium in fish eggs: Considerations for development of a Canadian tissue-based guideline. 8: Integrated Environmental Assessment and Management. [3] Rudolph B-L, Andreller I, Kennedy CJ Reproductive success, early life stage development, and survival of westslope cutthroat trout (Oncorhynchus clarki lewisi) exposed to elevated selenium in an area of active coal mining. Environmental Science and Technology 42: [4] DeForest D Database of selenium concentrations in fish tissues from reference sites. Washington DC (US): North American Metals Council - Selenium Working Group. 33 pp. Accessed on-line at: [5] McDonald BG, debruyn AMH, Elphick JRF, Davies M, Bustard D, Chapman PM Developmental toxicity of selenium to Dolly Varden char (Salvelinus malma). Environmental Toxicology and Chemistry 29:

4 Harry Ohlendorf General comment impacts of an overly-conservative selenium guideline could include (but are not limited to): Significant increases in operational costs; Inability to operate and expand operations (reduce jobs); Uncertainty for outside investors; and, Increases to the carbon footprint of industry operations due to the fact that water treatment to unnecessarily remove selenium requires significant increased energy inputs. 12 There are inherent implementation and monitoring challenges with a tissuebased guideline, in comparison with the use of a traditional water-based guideline. In order to improve the ability to derive a water-based value from a tissue-based value, the CISWG has recently commissioned research studies aimed at filling this gap. These studies were conducted by reputable private consulting firms, laboratories, and scientists at Natural Resources Canada. We have prepared a memorandum that contextualizes the data gaps we have addressed, and this document is also attached to this letter. This most recent research was not included for consideration in the current draft guideline, however, we believe that it could assist with setting more accurate water guidelines and alert levels from tissue-based guidelines than those that are presented in the revised draft guideline. CM2H Hill 128/ With reference to the draft recommended guideline for bird eggs, the value of 6 µg/g dry weight was derived by applying an uncertainty factor of 2 to a wellestablished low-effect level (EC10) for a relatively sensitive bird species (mallard) (analyses published by Adams et al. [2003] and Ohlendorf [2003]). The recommended value is slightly lower than the lower-bound estimate on the EC10, so it is very conservative. The document also describes an effect level for black-necked stilt and mallards as 6-7 µg/g dry weight (p. 128, lines 17-19). It should be noted that this value is based on stilts only (not mallards), and that it is described by the original author (Skorupa 1999, p. 1256) as an approximate EC03 for egg viability (hatchability). Nevertheless, the draft document (p. 190, lines 13-14) characterize the 6 µg/g dry weight concentration in bird eggs as follows: Concentrations above this constitute a Protection Division of MOE. The UF was determined by looking at the current science, literature and using professional judgment, taking into consideration the mode of action of Se and mechanism of exposure, whether Se is a required nutrient, other jurisdictional Se criteria or guidelines, lower confidence intervals for estimates of toxicity to fish, and typical background concentrations for Se in various media. See Section for more details. With respect to background fish tissue concentrations, please see the discussion in Section DeForest (2009) was cited, including figures 14, 15, 16 and 17, in the discussion of background tissue residues. In Section the comparison of typical background egg Se with the guideline is discussed. DeForest (2009) has been cited and further discussed here, and other exceptions have been noted (Rudolph et al. 2008; McDonald et al 2010) and discussed. While social and economic considerations are not evaluated in the derivation of guidelines, the Statutory Decision Maker may consider a number of factors when making a decision on a discharge permit. The BC Se WQG incorporates a series of values including water and fish tissues. The ability to translate a water or tissue guideline from the bioaccumulation relationship between the two compartments is important to verify that the guidelines are appropriate. Golder s westslope cutthroat trout BAF models (debruyn 2010) for lotic and lentic environments were used to compare the sitespecific lentic water-to-egg Se relationship with the proposed Se water guideline (see Section 8.4.1). The Golder BAF models are based on data collected in the Elk Valley and therefore represent site-specific Se bioaccumulation characteristics. The Golder BAF models are a one-step model, integrating the enrichment and transfer of Se through the food-web. As stated in DeForest (Technical Memo Feb ) a one-step model also integrates many of the uncertainties, such as the influence of Se speciation (selenite vs selenate vs organo-se), particulate-specific variability in Se enrichment, variability in dietary Se trophic transfer, site-specific biology, species-specific maternal transfer, modifying factors (sulphate, nitrate, phosphate, DOC), and the exposure of fish to Se, particularly species like WCT that forage widely in a watershed. The Golder BAF lentic model indicates the water guideline of 2 µg/l was reasonably protective under most circumstances, but also indicated the need for additional protection for lentic environments. Hence the inclusion of an alert concentration for water of 1 µg/l. (see Section 8.4.1) Page 128, We corrected the reference to mallards and stilts to read only stilts. Se thresholds based on one species may not protect all highly sensitive bird species or act as a surrogate for possibly more sensitive amphibians. It is suggested in the literature that other birds (grebes, coots and sandpiper) may be more sensitive to Se than mallards. More toxicological data is needed on the sensitive endpoints of other species of birds as well as for amphibians. A bird egg Se WQG of 6 µg/g is not much lower than the reported threshold for sandpiper (significant 15% reduction in hatchability at 7.3 µg/g egg Se). 4

5 Paul Paquin HDR/HydroQu al General comments high risk for reproductive effects to sensitive bird species. This overstates the risk of reproductive impairment for birds. 14 This document represents a significant effort towards the development of technically defensible water quality criteria for Se. As such, it serves as a useful reference document. Comments on many of the important areas that need to be addressed (e.g., the actual proposed guideline values) are deferred to others who have worked with and are more familiar with relevant details of supporting studies. However, I have included comments related to a limited number of specific technical areas, as mentioned below. Several errors of a typographical nature, missing and/or incorrect citations and the like are also included below. The draft document identifies several areas warranting further research. These include but are not necessarily limited to the following: site- and species-specific differences in uptake & compartmentalization of tissue Se biotransformation of Se at the base of the food web, mechanisms of uptake, ingestion, and assimilation rates, sequestration and inter-organ transfer of Se, and the induction of toxic effects and ability to regulate tissue Se (i.e., TTFs are not fixed) ; better ways of predicting Se bioaccumulation are being sought; sulphate interactions before a sulphate-corrected Se criteria should be adopted; interactions between Se and Hg on uptake and accumulation; oxidative stress as a mode of toxic action for Se in juvenile and adult organisms; relative sensitivity of Se in fish and wildlife species; reproductive versus non-reproductive toxicological endpoints; chronic effects thresholds for Se in sediment on a broad array of [benthic] invertebrate taxa and their life stages; toxicity thresholds for invertebrate prey species based on body burden before a guideline can be based on the analysis provided in debruyn and Chapman (2007); more definitive research is needed to ascertain Se toxicity thresholds [to protect highly sensitive invertebrate species] before a guideline is proposed; level of protection provided by a 4 μg/g whole-body tissue Se guideline for sensitive rainbow trout and to establish a more precise estimate of toxicity thresholds for ELS and juvenile rainbow trout and other sensitive fish species; studies of other wildlife species would be beneficial in establishing additional tissue guidelines for sensitive species. Given the preceding list, it would seem appropriate to consider the proposed guidelines as proposed interim guidelines until additional research results are available for consideration. The draft document also acknowledges various complexities related to Se fate, accumulation and effects, including the potential importance of physiological regulation, Se speciation in water and tissues, variability in BAFs, and the like. While waterborne, dietary and tissue residue guidelines are proposed, the draft document does not address or recommend procedures for relating waterborne Se exposure levels to tissue Se levels (or the reverse). These are The Se WQG was developed using the current state of the science. Minimum data requirements were met as per our protocol for developing water quality guidelines. The guidelines are subject to review and revision as new knowledge becomes available. Minimum data requirements were met for developing water column, fish tissue (whole-body and muscle) and wildlife guidelines. Where minimum data requirements were not met, interim guidelines were recommended as per our protocol. Alert concentrations have been recommended for the water column in sensitive environments and for sediments. These are not guidelines per se, but are triggers for further investigation. We agree that there is a need to develop site-specific Se relationships between the various compartments as stated in sections and We added some recommendations in Section 9. 5

6 areas that will be important in regard to effluent permitting. Feedback on such areas might be of use as part of this review. However, I have not attempted to do so because they are not directly considered in the draft document itself. 18/ Page 18, line 8: change effluents to effluent Page 18, line 9: change densities to density 44/8, 10, last paragraph 16 Page 44, line 8: strike and Page 44, line 10: Insert. after closing paren. Page 44, bottom paragraph: As a general comment, it would be helpful to readers if the number of significant figures used in the text were consistent with numbers in the tables. 45/Table Table 4.8: Concentrations for the impacted site (5.01 and 7.21 μg/g) are mentioned in the text on page 44 (line 18) and it would be appropriate to include in Table 4.8. Corrected. Corrected. Concentrations were added to the Table as suggested. We also added periphyton numbers for medium and high exposure sites to Table /Table Table 4.11: Concentrations for the impacted site (19.52 and μg/g) are mentioned in the text on page 54 (line 19) would be appropriate to include in Table 4.8. [assume he means Table 4.11 not 4.8 here] 70/12 19 Page 70, line 12: Appear to be one or more words missing. Perhaps it should state something like increase adsorption and partitioning of Se to particulates relative to competitive ions As it stands, it sounds like Se partitions to competitive ions Page 71-72, 3rd bulleted item in list: It would help to include citations for responding quickly to changes in water concentrations, and for trophic levels responding slowly. Although the statement seems like a reasonable one, consideration should be given to whether or not the response times are fast enough, or not fast enough, to be able to track changes in Se concentrations in water or food? Concentrations were added to the Table as suggested. Corrected. 73/2 21 Page 73, line 2: Should steams be changed to streams? Corrected. The statement was cited from Bowie et al. (1996), Ohlendorf (2003), and Maher et al. (2010). 75/27 22 Page 75, line 27: (Something doesn t look right with the citation for (Hamilton, 2004, 2004) and how it should be formatted with regard to the rest of the line. 77/ Page 77, line 1 & 2: bioaccumulation factors are ratios between sediment and tissue Se, or dietary and tissue Se should probably be changed to bioaccumulation factors are ratios between tissue Se and sediment Se, or tissue Se and dietary Se 82/7, 13, Page 82, line 7: change greater extent that lotic to greater extent than lotic Page 82, line 13: Should reference be Lemly (1993a) (or 1993b) rather than simply Page 82, line 19: Saiki et al should be added to the list of references. Otherwise, perhaps this line should refer to Saiki et al /13, 18, 19 86/5, last paragraph 25 Page 84, line 13: The citation for Turner and Swick 1983 is not included in the list of references. Page 84, line 18: The citation for Khan and Wang 2009 is not included in the list of references. Page 84, line 19: Fix spelling of predictable (not predicable ) 26 Page 86, line 5: Conley et al. (2011) is not listed with the references. Page 86, last paragraph: This paragraph implies that tissue Se would typically be expected to increase with age or size. However, for many constituents, the Corrected. Corrected. Corrected. Reference should be Lemly (1993b) Saiki et al. (2001) was added to references. Turner and Swick (1983), and Khan and Wang (2009) were added to references. Spelling of predictable was corrected. Conley et al. (2011) was added to the references. Agree. Wording has been changed to add clarity. 6

7 relationship may be a decrease in concentration with increasing age or size. Such a response reflects allometric relationships between uptake and assimilation rates, gill surface area and the like (factors that may vary with increasing size when expressed on a per unit weight basis). 99/9 27 Page 99, line 9: Hoffman 2002 is not included in the list of references Hoffman (2002) was added to the references. 101/1 28 Page 101, line 1: change though to through Corrected. 102/2, paragraph 1 29 Page 102, line 2: Section6.2 is missing a space. Page 102, Paragraph 1: While mobility may complicate relating environmental exposure to accumulation, it would not necessarily alter or complicate relationships between accumulation and effects. The authors may want to clarify this point. 106/28 30 Page 106, line 28: Shouldn t the units be 7,830 μg/l, not 7,830 μg/g? Corrected. 110/17, Page 110, line 17: The word stark: is unnecessary and somewhat provocative. Page 110, line 26: Change rom to from Removed the word stark. Added the f to from. 115/14 32 Page 115, line 14: Lemly 1996 is cited. It should be 1996a or 1996b, or perhaps Lemly (1996b) another reference should be added to the reference list (1996c?) 116/30 33 Page 116, line 30: Confirm that units are actually mg/l. The units are correct. Added a space Added a sentence, and made edits to next sentence to remove possible confusion. Now reads However, while mobility of an organism may complicate evaluation of Se exposure, it does not necessarily alter the relationship between Se accumulation and effects. The mobility of organisms has implications in evaluating site-specific exposure for some species, leaving some level of uncertainty in environmental risk assessments. 117/1, Page 117, line 1: change physiological above to physiological effect above. Page 117, line 21: The three parentheses shown on this line appear to be misplaced. 118/8 35 Page 118, line 8: Although it depends on what the authors actually intended, it seems to me that limit Se bioaccumulation to levels that might harm fish should be changed to limit Se bioaccumulation below levels that might harm fish or maintain Se bioaccumulation below levels that might harm fish. 119/1 st paragraph, Page 119, first paragraph: Without researching this in further detail, the discussion of Figure 7.1 leaves me wondering whether or not the elevated water concentration is causing the elevated sediment Se, or if the reverse might be true (reversing the axes would indicate dissolved Se a function of sediment Se.). Either situation might be true, depending on the point in time relative to the historical loading to the system. Mention is made of porewater concentrations. Were they higher than overlying water concentrations? If so, this would suggest the sediment might be a net source to the water column, via a diffusive flux of porewater Se to the water column. As a minimum, if the original publication provides a more detailed rationale for why water column Se is driving sediment Se concentrations, this should be mentioned. Otherwise, correlation does not demonstrate causality, and the authors should use caution in inferring causality from results of Figure 7.1. Page 119, Line 22: Change link between sediment in Se and food web bioaccumulation to link between Se in sediment and bioaccumulation of Se in the food web 124/10 37 Page 124, line 10: Change appears to be a fairly tolerant to Se to appears to be fairly tolerant to Se Added effect Removed bracket. Changed wording. Now reads The San Francisco Bay Regional Water Quality Control Board recommended a site-specific water quality criterion of 0.1 to 0.8 µg/l, thereby limiting Se bioaccumulation and tissue concentrations below levels that might harm fish, birds and humans (Pease et al. 1992). In Wiramanaden et al. (2010) there were relationships between surface water, pore water, sediment, and chironomid tissue. From figure 2 (b), pore water [Se] was not greater than surface water [Se] suggesting that pore water was not a significant source of Se to the water column. The authors did not discuss the possible flux of pore water into overlying surface waters as a source of Se. We used this as an example to point out that increasing water Se is correlated to increases in sediment Se. The authors stated that Se from the water column was being transformed by sediment microbes which supports other research suggesting this is at least one of the major mechanisms for incorporation of Se into sediments. Corrected. Now reads link between Se in sediment and bioaccumulation of Se in the food web Corrected. 7

8 125/23 38 Page 125, line 23: Should Figure 6.3 be Figure 7.2? I didn t check all of the figure numbers, but I have the impression that some others may be incorrect as well. Perhaps there was a change in section numbering at some point (when Section 1 was inserted?) and the figure numbers were not all carefully updated throughout the document. 126/12, Page 126, line 12: replace that in with for Page 126, line 13: Should Figure 6.4 be Figure /24 40 Page 128, line 14: My copy is marked up a bit, but it looks like 5.0 μg/g. has an extraneous character after μg/g 138/26 41 Page 138, line 26: Consider inserting Schwarz, 2011 after Appendix A and also add the citation for Schwarz 2011 to the reference list. 154/21 42 Page 154, line 21: Cumbie and Van Horn 1978 needs to be added to the reference list. 156/11, Page 156, line 11: represents should be represent Page 156, line 16: Is it supposed to be 2011b or 2010b. If 2011b, need to add one or two refs to reference list. Alternatively, update the citation for 2010b if it has recently been updated to a final version that was a draft in /5 44 Page 157, line 5: Please clarify if the concentration range reported for the 11 reference sites represents a range of mean values for the 11 sites, or an overall range of grab sample concentrations at the 11 sites , 1 st 45 Page , first paragraph: The calculation that arrives at 4 μg/gd (previous paragraph BC Tissue Guideline) involves rounding off an intermediate result of 1.2 μg/gw to 1.0 μg/gw. If the significant figures were preserved until the end of the analysis that is described, the end result would be 20% higher, at 4.8 μg/gd. Rounding off of intermediate results leads to a propagation of errors and should be avoided. A value of 4.8 μg/g is generally consistent with many of the other measured dietary threshold levels (as opposed to estimates or predicted dietary thresholds) discussed on pages μg/gd LOEC for adult chickens 4.4 μg/gd (previously 4.9 μg/gd) for 6 studies of mallard ducks (Note that Table 8.12 reports mallard NOECs of 3.9 and 4.4 μg/gd) 4.7 and 10.2 μg/gd led to a decrease in hatchability for Elk Valley spotted sandpiper (Harden and Paton, 2003) Subsequent to the reporting of the effect level of 4.7 μg/gd, a 5 μg/gd dietary trigger was proposed for Elk Valley (protective of aquatic invertebrates and fish and wildlife that prey on them) (Canton et al., 2008). Elsewhere, a review of available toxicological data supported a 4.9 μg/gd dietary EC10 for hatchability in GSL birds (CH2M Hill, 2008). The preceding results are within the range of 3 7 μg/gd that were proposed as posing a marginal risk to aquatic life (USDOI, 1998; Presser et al., 2004). While other considerations have been put forth in support of a higher threshold, these data alone seem more supportive of a tissue threshold level of 5 μg/gd than 4 μg/gd. 161/11, Page 161, lines 11, 12: Years indicated for Hicks et al., 1984 and Cleveland et al are inconsistent with the reference list (1983 and 1993, respectively). Fix the text or the reference list, as appropriate. Figure numbers were corrected. Corrected No extraneous character was found. Schwarz (2011) was added to text and references and the pdf of Appendix A is available on the BC MoE website at Reference was added. Corrected. Golder (2010b) is correct. Concentrations were mean concentrations reported at the sites. Nagpal and Howell (2001) developed their whole-body Se tissue guideline expressed as a wet weight concentration that was rounded to the nearest whole number. This number was not an intermediate value and was published in both the Overview and Technical Appendix as 1.0 µg/g Se wet weight. The number was later converted to dry weight assuming 75% moisture content recommended by Lemly (1996a). The dry wt Se concentration was compared to existing literature and is consistent with the lowest toxicity thresholds based on whole-body Se and takes into account the 95 % CIs of those estimates. The interim dietary WQG selected of 4 µg/g dw was selected, which considers the lower published dietary toxicity thresholds for fish that are below 5 (see Section , Goettl and Davis 1978; Hilton et al. 1980; Hilton and Hodson 1983; Vidal et al. 2005) as well as the published 95% CIs below 4 (Ohlendorf 2007; Wayland et al. 2007; CH2M Hill 2008). Hicks et al. (1984) and Cleveland et al. (1993) Corrected. 8

9 164/23 47 Page 164, line 23: Vidal is designated an unacceptable study in the text, while in the table it is flagged as being a secondary study (2o). 165/ Table 48 Page 165, last column of Table 8.12: Ort and Latshaw is not included in the list 8.12 of references. 168/21 49 Page 168, line 21: Unless I misunderstand this sentence and the following paragraph, it seems to be the case that acceptable should be changed to unacceptable (U). 168/28 50 Page 168, line 24: To be consistent with the table, NOEC of 16.0 should be changed to NOEC of > / Page 171, lines 1-5: Given the limitations of field study results, and the possibility that other stressors may have caused or contributes to effects, it should be stated that these data provide an indication of a lower bounds on effect thresholds. 172/10, Page 172, line 10: The meaning of (only 3 5 μg/g Se less than) is unclear. Page 172, line 19: Please insert the value(s) for the Se in eggs in the reference areas sampled by Holm et al. 173/multipl e 53 Page 173, 1st paragraph: In this statement of the criterion, I was wondering if it should refer to individual salmonid females rather than individual females. Similarly in some subsequent statements of the criteria (e.g., bold text on page 178 at least 5 salmonid samples ). Considering line 8 on page 183, it appears as if the authors may have been thinking along similar lines, when they refer to: sensitive salmonid (fish?) species. That said, it isn t clear what the parenthetical (fish?) was meant to indicate. Page 173, line 18: It seems as if results by Hodson et al. (1980) should be included in Table Page 173, line 22: Delete had higher than acceptable control mortality (it is redundant) Page 173, line 23: It would seem to be appropriate to replace but with and Page 173, paragraph 3, last sentence: Three studies were supposedly unacceptable, but only two are mentioned. Corrected the table. Added Ort and Latshaw (1978) to references Yes, corrected. Added > Field results provide an indication of the possible range of effect thresholds, as opposed to just the lower bounds of effect thresholds. It depends on the other stressors and co-contaminants, some of which may ameliorate (lessen) the effects of Se. Field studies provide valuable information on the range of effect thresholds in the environment. Corrected. Now reads The predicted population-level effect concentration for westslope cutthroat trout is only 3 to 5 µg/g Se greater than the EC10 toxicity threshold for individual fish. Egg Se values from Holm et al. (2005) were inserted. Replaced salmonid with fish in all cases. The guideline used primarily salmonid species to derive the numbers but should protect all fish species. Hodson et al. (1980), reported Se body-burden for only the control and highest dose Se (50 µg/l) groups, representing LOEC for reduced growth (length), therefore no WB Se tissue data was reported for groups that showed significant effects at lower doses for other endpoints like decreased Ca in bone (12 µg/l), reduced median time to hatch (16 µg/l) and reduced survival of eyed eggs (26 and 47 µg/l exposure groups). Will add it to the table since it is mentioned in the text (page 176) with a description of what the data represent. Edits on page 173/21, 22, 23 were made as suggested. 174/12 54 Line 174, line 12: For consistency with table, replace 4.8 with < 4.8 Added <. 176/3 55 Page 176, line 3. Tabulated value for Hunn et al. indicates a LOEC of 4.4, not 4.3. Table does not include the result for Hodson et al. (1.8 μg/g?) that is mentioned in same sentence. 176/15 56 Page 176, line 15: The text should indicate what the basis is for an uncertainty factor of /20 57 Page 192, line 20: Ohlendorf et al. 2010, or should it be If 2010, add full citation to reference list Pages 178 & 179: I had difficulty following the derivation of various tissue concentrations mentioned in the text. The discussion should be clarified to make it clear how various numbers are arrived at. For example, on page 179, lines 17-25, mention is made of 7-fold higher tissue Se concentrations mean muscle compared to mean egg in rainbow trout. As written, it sounds as if muscle Se = 7 x egg Se, which doesn t seem reasonable. EC15s of 8 10 μg/gw Values were re-calculated and corrected. Additional details were added. Added some additional text to clarify basis for the UF of 2 applied to DeForest and Adams (2011) 8.1 WB effect threshold. Ohlendorf et al. (2011) is the correct reference. The beginning of Section 4.2 Residues (page 20-21), states that all Se concentrations have been put into common units and for tissue residues have been converted into dry weight using either the reported % moisture or an assumed % moisture (stated). For added clarity this statement was added to Section

10 egg Se are then converted to μg/gd in muscle tissue based on 75% moisture content (as opposed to 61% moisture in Table 8.13), but it isn t obvious how this conversion is made. Other values are mentioned and, at the end of the paragraph, a statement is made that the preceding results support a guideline of 4 μg/g in fish muscle tissue. The basis for this statement isn t clear from the numbers presented, at least not to my reading of the paragraph. Also, please be explicit when referring to dry weight and wet weight concentrations. 180/12 59 Page 180, line 12. At end of sentence, replace μg/g ( ). with μg/g ( ) (values listed in table 8.15). 183/15 60 Page 183, line 15: change the word ion to in. Corrected. 194/18 61 Page 194, line 18: It looks as if inference should be interference. Corrected. Page 179 has been changed to read Holm et al. (2005) found that in rainbow trout, mean egg Se concentrations were 7-fold higher than mean muscle Se (reported as wet weight concentrations). Using this simple relationship, the reported egg-based toxicity threshold (EC15 of 8.8 to 10.5 µg/g egg Se, wet weight) for larval deformity in rainbow trout is calculated to be 5 to 6 µg/g (dry weight, assuming 75% moisture) in muscle tissue (Holm et al. 2005) A footnote was added explaining how the calculation was done, which reads The reported EC15 range of 8.8 to 10.5 µg/g egg Se wet weight, was divided by seven to yield the corresponding Se effect threshold range for muscle (1.25 to 1.5 µg/g wet weight). This was then converted to dry weight using 75% moisture content. Corrected. Dr. K. McCallum Saskatchewan Ministry of Environment submitted integrated agency and References 62 References: Note that I only spot-checked references as I went through the text. The following list doesn t reflect a thorough check of the reference list. Such a check of references cited in text and listed in Section 10.0 should be performed. Fix Calello, 2010 (page 198). The year is missing after the author s name, and extraneous characters ( ) are inserted prior to the page numbers. Year indicated for Cleveland et al (page 161, line 12) is inconsistent with the reference list (Cleveland et al., 1993). Fix the text or the reference list, as appropriate. Add Conley et al., 2011 (mentioned on p. 86); Cumbie and Van Horn 1978 (mentioned on page 154, line 21) needs to be added to reference list. Year indicated for Hicks et al., 1984 (page 161, lines 11, 12) is inconsistent with the reference list (Hicks et al., 1983). Fix the text or the reference list, as appropriate. Add Hoffman 2002 (mentioned on Page 99, line 9) to the list of references (on page 211) Add Khan and Wang, 2009 (mentioned on p. 84 but missing on page 213); Lemly 1996 is cited on page 115, line 14. It should be 1996a or 1996b (or perhaps another reference should be added to the reference list: 1996c?) Check Ohlendorf et al or add Ohlendorf et al., 2011, to clarify p. 192; Add Ort and Latshaw (shown in last column of Table 8.12) Fix Saiki et al. 2004, or add Saiki et al (p. 82) Add Turner and Swick, 1983 (cited on p. 84 but missing on page 232) Yang et al., 1983 is mentioned at least 3 times on Page 95, last paragraph. On page 236 of the reference list only Yang and Zhou, 1983 is shown. Need to fix the text or the reference list. General comments 63 Note that care is required in determining the level of appropriate conservatism. Clearly where exceedance has a high likelihood of catastrophic, irreversible environmental effects a very high level of caution and thus of conservatism is required. However, where such a high likelihood is not expected, as is apparently the case with selenium, care must be taken to Edits have been made to references. The aim of WQGs is to protect all species and all sensitive life stages, indefinitely. At very low water concentrations Se can bioaccumulate through the food web causing reproductive effects in adults. There is a complexity of factors that govern the magnitude of accumulation and responses in organisms that are both species- and site-specific. The full range and effect thresholds for sensitive early 10

11 industry comments. 1-5 /Introductio n ensure that the level of conservatism is not too high for three reasons, all related to discriminating real problems from those that are not: 1. Provincial and national environmental staff resources are not unlimited. Although as Meays (2012) and the subject document both emphasize, sitespecific objectives can be developed, such require intensive regulatory input. Regulatory resources are increasingly scarce and need to be focused on real issues, real problems and real solutions. WQGs should not be set at such a low level that those limited resources are strained with no environmental benefit. 2. The examples of large-scale adverse Se effects seem to be relatively few and reversible. The subject document discusses at some length two examples of large-scale adverse Se effects: Belews Lake and Kesterton Reservoir, which have now recovered (i.e., Se pollution was not irreversible). Otherwise, the examples cited appear to be generally of potential for such effects rather than their realization, e.g., based on modelling, laboratory toxicity tests, and extrapolation. 3. Industrial environmental staff resources are not unlimited. Industrial developments should not be penalized by overly conservative generic WQGs that do not provide additional environmental benefits compared to somewhat higher WQGs. The monies and staffing of industrial entities, like those of provincial and national environmental agencies, are similarly not unlimited. Again the focus needs to be on appropriate protection and discrimination, not on unnecessarily conservative WQGs. 64 the purpose of the WQG is intended for broad, generic provincial application and may not account for site-specific biological factors (page 2). In fact, the document acknowledges that water quality guidelines do not have any direct legal standing in BC (page 3) but once approved, must be considered in any decision making affecting water quality, including the establishment of discharge permits, approvals, plans and operating certificates. A clear statement about the hierarchy of guidelines is therefore required. Additionally, we anticipate that many of those making decisions regarding water quality will simply adopt the guideline values because staff resources are exceedingly limited. Guidance on how to implement the desired adaptive management approach to evaluate and if necessary mitigate the effects of Se (page 5) and how to derive site-specific water quality objectives (page 1) has not been provided but is critical to the successful adoption of the Se water quality guidelines under these circumstances. 4/ 65 It is stated that the USEPA first published their Se draft water quality criterion (WQC) in It was first published in 2002, and remains a draft WQC; the word draft should be used for this document. Clarity from Bioaccumul ation Framework - Section 5 & 6 66 The biogeochemical cycling of Se forms the scientific foundation for understanding and managing Se impacts in the environment. Unlike most WQG technical appendices, this document goes well beyond the standard compilation of toxicological data and discussion of the derivation of a protective guideline: it offers numerous conclusions about the magnitude of risk associated with Se concentrations. As such, it needs to provide the necessary scientific basis for those conclusions. Sections 5 and 6 of the document provide much of the underlying information but need to be refined so that subsequent decisions about data selection and guideline derivation are based on the biogeochemical framework. For example: 1. The simplified Se life stage and juvenile fish are not as well researched but much of the existing literature suggests those effect thresholds are low. The need for conservatism is illustrated by the very steep slope of the Se dose-response curve, which suggests increasingly higher risks of toxic responses with only small increments of Se above the effect threshold. While effects may be reversible, the recoveries can take years if not decades due to Se recycling through sediments and biota (see examples in Section 5.4). Furthermore, if severe effects do occur, recovery may be irreversible in environments where geographically isolated populations have no in-migration of individuals. The current scientific literature has many examples of severe impacts, areas that have been very slow to recover and areas where recovery is often not complete after decades. A link to the Ministry s protocols for development of water quality objectives can be found at Draft has been added. 1. The information in sections 5 and 6 are presented as general discussions. How these factors translate into guideline derivation is presented in Section 8.4. The differences between lotic and lentic accumulation characteristics and risks have not been ignored in derivation of the Se WQGs. Please see discussion in Section 8.4. Lotic and lentic hydrologic units are closely linked and integrated within stream reaches, and given the goal is to protect the most sensitive, it is not necessary to develop separate lotic and lentic guidelines. 2. Sections 5 and 6 are not meant to be exhaustive assessments but to introduce the reader to the complexity of Se behaviour in the environment. Nor is this a risk assessment so the term conceptual model may not be completely 11