Amd 1_1240LP26Q0090.pdf

(x)

1240LP26Q0090

x x

1 copies of the amendment; (b) By acknowledging receipt of this amendment on each copy of the offer submitted ; or (c) By separate letter or electronic communication which includes a reference to the solicitation and amendment numbers. FAILURE OF YOUR ACKNOWLEDGEMENT TO BE

RECEIVED AT THE PLACE DESIGNATED FOR THE RECEIPT OF OFFERS PRIOR TO THE HOUR AND DATE SPECIFIED MAY RESULT IN REJECTION OF YOUR

OFFER. If by virtue of this amendment you desire to change an offer already submitted , such change may be made by letter or electronic communication, provided each letter or electronic communication makes reference to the solicitation and this amendment, and is received prior to the opening hour and date specified.

x

40LP

OGDEN UT 84401-2310

324 25TH ST

USDA-FS CSA INTERMOUNTAIN 4

06/18/20260001

13. THIS ITEM ONLY APPLIES TO MODIFICATION OF CONTRACTS/ORDERS. IT MODIFIES THE CONTRACT/ORDER NO. AS DESCRIBED IN ITEM 14.

12. ACCOUNTING AND APPROPRIATION DATA (If required) is not extended.is extended, Items 8 and 15, and returning

Offers must acknowledge receipt of this amendment prior to the hour and date specified in the solicitation or as amended , by one of the following methods: (a) By completing

The above numbered solicitation is amended as set forth in Item 14. The hour and date specified for receipt of Offers

11. THIS ITEM ONLY APPLIES TO AMENDMENTS OF SOLICITATIONS

FACILITY CODE CODE

10B. DATED (SEE ITEM 13)

10A. MODIFICATION OF CONTRACT/ORDER NO.

9B. DATED (SEE ITEM 11)

9A. AMENDMENT OF SOLICITATION NO.

CODE

8. NAME AND ADDRESS OF CONTRACTOR (No., street, county, State and ZIP Code)

7. ADMINISTERED BY (If other than Item 6)CODE 6. ISSUED BY

PAGE OF PAGES

4. REQUISITION/PURCHASE REQ. NO.3. EFFECTIVE DATE2. AMENDMENT/MODIFICATION NO. 5. PROJECT NO. (If applicable)

1. CONTRACT ID CODE

AMENDMENT OF SOLICITATION/MODIFICATION OF CONTRACT

06/11/2026

CHECK ONE A. THIS CHANGE ORDER IS ISSUED PURSUANT TO: (Specify authority) THE CHANGES SET FORTH IN ITEM 14 ARE MADE IN THE CONTRACT

B. THE ABOVE NUMBERED CONTRACT/ORDER IS MODIFIED TO REFLECT THE ADMINISTRATIVE CHANGES (such as changes in paying office, C. THIS SUPPLEMENTAL AGREEMENT IS ENTERED INTO PURSUANT TO AUTHORITY OF:

D. OTHER (Specify type of modification and authority) appropriation data, etc.) SET FORTH IN ITEM 14, PURSUANT TO THE AUTHORITY OF FAR 43.103(b).

E. IMPORTANT: Contractor is not is required to sign this document and return __________________ copies to the issuing office.

ORDER NO. IN ITEM 10A.

14. DESCRIPTION OF AMENDMENT/MODIFICATION (Organized by UCF section headings, including solicitation/contract subject matter where feasible.)

FOB: Destination

Period of Performance: 01/01/2027 to 12/31/2027

16A. NAME AND TITLE OF CONTRACTING OFFICER (Type or print)15A. NAME AND TITLE OF SIGNER (Type or print)

15C. DATE SIGNED 16B. UNITED STATES OF AMERICA 15B. CONTRACTOR/OFFEROR 16C. DATE SIGNED

(Signature of person authorized to sign) (Signature of Contracting Officer)

STEPHEN D. HOLLY

STANDARD FORM 30 (REV. 11/2016)

Prescribed by GSA FAR (48 CFR) 53.243

Previous edition unusable

Except as provided herein, all terms and conditions of the document referenced in Item 9 A or 10A, as heretofore changed, remains unchanged and in full force and effect .

Questions and Answers regarding solicitation

1240LP26Q0090- Fisheries and Wildlife/Macroinvertebrate Analysis

1. Will emailed material as part of a quote package be acceptable as the form of delivery? If so are you also the POC for said email?

Answer: Yes, solicitation responses must be received, to Stephen.holly@usda.gov, in email/attachment form, prior to the solicitation closing time.

2. The bid materials suggest up to 24 samples collected in 2026 and 2027, will this be approximately 12 samples each year?

Answer: Yes, we anticipate collecting 12 samples each in 2026 and 2027. There could be as few as 10 in any year but no more than 14 in any one year.

3. When, what time of year, will samples be collected? The POP ends 8/31/2027, which is a common time of year to collect BMI samples. If samples are to be delivered to the offeror in August - October and a three-month turnaround, the 2027 collected samples will likely not be completed within the POP.

Answer: Correct, our field collection season is mid-July through end of August. We anticipate having all samples collected and ready to ship by the end of August but at the latest by early September each year. It light of this the Period of Performance is now adjusted to January 1, 2027 through December 31, 2027.

4. This solicitation is marked as a Request for Quote; however, the technical approach and past performance requirements require a detailed description of how the offeror is to complete the SOW and describe past work. Are there page limitations to the quote?

Answer: There is a 10-page maximum limitation for the technical volume of the solicitation response.

5. Deliverables:

a. The deliverables list electronic AND hard copy datasheets, will hard copy spreadsheets truly be required?

Answer: We prefer to have a hard copy as well for our records, this can be added to the shipment when the macroinvertebrates are shipped back to the Forest Service. Hard copy datasheets are still part of the requirement.

b. The deliverables do not list calculating the MMI, however it is priced out in the description of work.

Answer: Correct, calculation of MMI for each sample is part of the overall cost per sample. No amendment to the Schedule of Items will be made.

c. Can USFS provide a template for deliverables?

Answer: Attached to Amendment 1 are example copies of MMI data and sample data from 2022 (labeled as examples). The contractor shall process the benthic macroinvertebrate samples to the standards of the method described in the Standard Operating Procedure for Laboratory Identification and Enumeration by Colorado Dept of Public Health and Environment (2017).

https://www.coloradosmp.org/wp-content/uploads/2022/03/Policy-10-1-v.- 2020.pdf. Appendix C is most relevant for calculation and sample processing (Policy 10-1 document- Appendix C starts on pdf page “143”).

https://gcc02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.coloradosmp.org%2Fwp-content%2Fuploads%2F2022%2F03%2FPolicy-10-1-v.-2020.pdf&data=05%7C02%7CStephen.Holly%40usda.gov%7C6d49da1eb0d64d40552908decc7ca865%7Ced5b36e701ee4ebc867ee03cfa0d4697%7C1%7C0%7C639173033324259788%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=iM05DJq%2FF9yQFhCaUaMD4vty1wYHAzcRD8fOTDzbEb8%3D&reserved=0 https://gcc02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.coloradosmp.org%2Fwp-content%2Fuploads%2F2022%2F03%2FPolicy-10-1-v.-2020.pdf&data=05%7C02%7CStephen.Holly%40usda.gov%7C6d49da1eb0d64d40552908decc7ca865%7Ced5b36e701ee4ebc867ee03cfa0d4697%7C1%7C0%7C639173033324259788%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=iM05DJq%2FF9yQFhCaUaMD4vty1wYHAzcRD8fOTDzbEb8%3D&reserved=0

2022 metrics summary

WJR22-001 WJR22-002 WJR22-003 WJR22-004

8/12/22 8/16/22 8/16/22 8/16/22

Community Metrics

Total Density (N/m2) 335 139 995 1675

Diversity (d) 1.44 3.34 3.76 3.68

Total Number of Taxa 19 19 34 34

No. EPT taxa 6 13 15 18

No. Ephemeroptera taxa 2 6 7 7

No. Plecoptera taxa 4 4 2 6

No. Trichoptera taxa 0 3 6 5

% EPT 12.84 86.33 75.08 75.22

% Ephemeroptera 8.36 59.71 54.27 47.46

No. Intolerant taxa 7 13 16 19

% Tolerant Organisms 1.79 1.44 3.92 5.97

% Dominant Taxon 78.81 17.99 26.53 28.06

HBI 4.04 2.03 1.95 1.94

BCI 9.25 3.48 4.29 4.11

% Filterers 0.00 24.46 3.02 11.94

% Scrapers 0.60 42.45 36.48 30.75

% Predators 1.19 4.32 4.72 3.28

% Shredders 5.37 3.60 4.22 11.04

No. Clinger taxa 6 13 16 19

% Clingers 82.69 76.26 72.36 74.03

No. Diptera taxa 8 5 13 11

No. Chironomidae taxa 5 3 8 6

% Diptera 5.07 12.95 15.88 12.54

% Chironomidae 1.79 5.76 12.96 2.39

% Tribe Tanytarsini 0.30 0.00 7.84 0.30

% Heptageniidae 2.09 23.02 18.69 11.34

No. Metal Intolerant species 0 4 4 5

No. WRNF Intolerant species 0 5 5 5

CO-MMI 33.6 61.2 75.3 77.3

Relative Abundance by Order

TURBELLARIA 1.49 0.00 0.30 0.00

NEMATODA 0.00 0.72 0.00 0.00

OLIGOCHAETA 1.49 0.00 2.11 5.37

EPHEMEROPTERA 8.36 59.71 54.27 47.46

PLECOPTERA 4.48 6.47 2.41 1.79

TRICHOPTERA 0.00 20.14 18.39 25.97

COLEOPTERA 79.10 0.00 6.63 6.27

DIPTERA 5.07 12.95 15.88 12.54

BIVALVIA 0.00 0.00 0.00 0.60

Totals: 100.00 100.00 100.00 100.00

Density by Order

TURBELLARIA 5 0 3 0

NEMATODA 0 1 0 0

OLIGOCHAETA 5 0 21 90

EPHEMEROPTERA 28 83 540 795

PLECOPTERA 15 9 24 30

TRICHOPTERA 0 28 183 435

COLEOPTERA 265 0 66 105

DIPTERA 17 18 158 210

BIVALVIA 0 0 0 10

Totals: 335 139 995 1675

&"Arial,Bold"&8MACROINVERTEBRATE SUMMARY DATA &"Arial,Italic"&8USFS Rio Grande NF 2022

&"Arial,Italic"&8Aquatics Associates, Inc. &"Arial,Italic"&8February 2023

WJR22-001

WJR22-001 Middle Fork Carnero Creek, at Carnero Guard Station

Sample Date: 8/12/22 Relative

Kick Sample Abundance

Taxon n N/m2 (%)

TURBELLARIA

Polycelis coronata 5 5.00 1.49

NEMATODA

OLIGOCHAETA

Enchytraeidae 3 3.00 0.90

Tubificidae with hair chaetae

Tubificidae w/o hair chaetae 2 2.00 0.60

EPHEMEROPTERA

Ameletus sp.

Baetis tricaudatus 26 26.00 7.76

Drunella doddsi

Drunella grandis

Ecdyonurus criddlei 2 2.00 0.60

Epeorus longimanus

Ephemerella sp.

Ephemerella tibialis

Rhithrogena sp.

PLECOPTERA

Amphinemura banksi 5 5.00 1.49

Capniidae

Chloroperlidae 1 1.00 0.30

Diura knowltoni

Hesperoperla pacifica

Isogenoides sp.

Megarcys signata

Perlodidae 1 1.00 0.30

Pteronarcella badia 8 8.00 2.39

Skwala americana

Sweltsa sp.

TRICHOPTERA

Agapetus boulderensis

Arctopsyche grandis

Brachycentrus americanus

Brachycentrus occidentalis

Glossosoma sp.

Lepidostoma sp.

Oligophlebodes minutus

Rhyacophila brunnea group

COLEOPTERA

Heterlimnius corpulentus 264 264.00 78.81

Optioservus sp. 1 1.00 0.30

DIPTERA

Antocha sp.

Atherix pachypus

Brillia sp. 1 1.00 0.30

Ceratopogonidae

Clinocera sp.

Conchapelopia sp.

Diamesa sp.

Dicranota sp. 3 3.00 0.90

Eukiefferiella sp.

Hexatoma sp.

Hydrobaenus sp. 1 1.00 0.30

Micropsectra sp. 1 1.00 0.30

Odontomesa sp.

Orthocladius sp.

Pagastia sp. 1 1.00 0.30

Paratendipes sp.

Pericoma/Telmatoscopus sp.

Polypedilum sp.

Ptychoptera sp. 7 7.00 2.09

Radotanypus sp.

Rheocricotopus sp.

Simulium sp.

Stempellinella sp.

Tipula sp. 1 1.00 0.30

Tvetenia sp. 2 2.00 0.60

BIVALVIA

Pisidium sp.

Totals: 335 335.00 100.00

Total Density (N/m2) 335

Total Number of Taxa 19

Diversity (d) 1.44

WJR22-001 Middle Fork Carnero Creek, at Carnero Guard Station

Community Metrics

Total Density (N/m2) 335

Diversity (d) 1.44

Total Number of Taxa 19

No. EPT taxa 6

No. Ephemeroptera taxa 2

No. Plecoptera taxa 4

No. Trichoptera taxa 0

% EPT 12.84

% Ephemeroptera 8.36

No. Intolerant taxa 7

% Tolerant Organisms 1.79

% Dominant Taxon 78.81

HBI 4.04

BCI 9.25

% Filterers 0.00

% Scrapers 0.60

% Predators 1.19

% Shredders 5.37

No. Clinger taxa 6

% Clingers 82.69

No. Diptera taxa 8

No. Chironomidae taxa 5

% Diptera 5.07

% Chironomidae 1.79

% Tribe Tanytarsini 0.30

% Heptageniidae 2.09

No. Metal Intolerant species 0

No. WRNF Intolerant species 0

Relative Abundance by Order

TURBELLARIA 1.49

NEMATODA 0.00

OLIGOCHAETA 1.49

EPHEMEROPTERA 8.36

PLECOPTERA 4.48

TRICHOPTERA 0.00

COLEOPTERA 79.10

DIPTERA 5.07

BIVALVIA 0.00

Totals: 100.00

Density by Order

TURBELLARIA 5

NEMATODA 0

OLIGOCHAETA 5

EPHEMEROPTERA 28

PLECOPTERA 15

TRICHOPTERA 0

COLEOPTERA 265

DIPTERA 17

BIVALVIA 0

Totals: 335

&8&A &"Arial,Italic"&8USFS Rio Grande NF 2022

&"Arial,Italic"&8Aquatics Associates, Inc. &"Arial,Italic"&8February 2023

WJR22-002

WJR22-002 Archuleta Creek, 3/4 mi. above Rio Chama confluence

Sample Date: 8/16/22 Relative

Kick Sample Abundance

Taxon n N/m2 (%)

TURBELLARIA

Polycelis coronata

NEMATODA 1 1.00 0.72

OLIGOCHAETA

Enchytraeidae

Tubificidae with hair chaetae

Tubificidae w/o hair chaetae

EPHEMEROPTERA

Ameletus sp.

Baetis tricaudatus 23 23.00 16.55

Drunella doddsi 25 25.00 17.99

Drunella grandis 2 2.00 1.44

Ecdyonurus criddlei

Epeorus longimanus 21 21.00 15.11

Ephemerella sp. 1 1.00 0.72

Ephemerella tibialis

Rhithrogena sp. 11 11.00 7.91

PLECOPTERA

Amphinemura banksi

Capniidae

Chloroperlidae

Diura knowltoni

Hesperoperla pacifica 1 1.00 0.72

Isogenoides sp. 1 1.00 0.72

Megarcys signata 2 2.00 1.44

Perlodidae

Pteronarcella badia 5 5.00 3.60

Skwala americana

Sweltsa sp.

TRICHOPTERA

Agapetus boulderensis

Arctopsyche grandis 25 25.00 17.99

Brachycentrus americanus

Brachycentrus occidentalis

Glossosoma sp. 2 2.00 1.44

Lepidostoma sp.

Oligophlebodes minutus

Rhyacophila brunnea group 1 1.00 0.72

COLEOPTERA

Heterlimnius corpulentus

Optioservus sp.

DIPTERA

Antocha sp.

Atherix pachypus 1 1.00 0.72

Brillia sp.

Ceratopogonidae

Clinocera sp.

Conchapelopia sp.

Diamesa sp.

Dicranota sp.

Eukiefferiella sp. 2 2.00 1.44

Hexatoma sp.

Hydrobaenus sp.

Micropsectra sp.

Odontomesa sp.

Orthocladius sp.

Pagastia sp.

Paratendipes sp.

Pericoma/Telmatoscopus sp.

Polypedilum sp.

Ptychoptera sp.

Radotanypus sp.

Rheocricotopus sp. 2 2.00 1.44

Simulium sp. 9 9.00 6.47

Stempellinella sp.

Tipula sp.

Tvetenia sp. 4 4.00 2.88

BIVALVIA

Pisidium sp.

Totals: 139 139.00 100.00

Total Density (N/m2) 139

Total Number of Taxa 19

Diversity (d) 3.34

WJR22-002 Archuleta Creek, 3/4 mi. above Rio Chama confluence

Community Metrics

Total Density (N/m2) 139

Diversity (d) 3.34

Total Number of Taxa 19

No. EPT taxa 13

No. Ephemeroptera taxa 6

No. Plecoptera taxa 4

No. Trichoptera taxa 3

% EPT 86.33

% Ephemeroptera 59.71

No. Intolerant taxa 13

% Tolerant Organisms 1.44

% Dominant Taxon 17.99

HBI 2.03

BCI 3.48

% Filterers 24.46

% Scrapers 42.45

% Predators 4.32

% Shredders 3.60

No. Clinger taxa 13

% Clingers 76.26

No. Diptera taxa 5

No. Chironomidae taxa 3

% Diptera 12.95

% Chironomidae 5.76

% Tribe Tanytarsini 0.00

% Heptageniidae 23.02

No. Metal Intolerant species 4

No. WRNF Intolerant species 5

Relative Abundance by Order

TURBELLARIA 0.00

NEMATODA 0.72

OLIGOCHAETA 0.00

EPHEMEROPTERA 59.71

PLECOPTERA 6.47

TRICHOPTERA 20.14

COLEOPTERA 0.00

DIPTERA 12.95

BIVALVIA 0.00

Totals: 100.00

Density by Order

TURBELLARIA 0

NEMATODA 1

OLIGOCHAETA 0

EPHEMEROPTERA 83

PLECOPTERA 9

TRICHOPTERA 28

COLEOPTERA 0

DIPTERA 18

BIVALVIA 0

Totals: 139

&8&A &"Arial,Italic"&8USFS Rio Grande NF 2022

&"Arial,Italic"&8Aquatics Associates, Inc. &"Arial,Italic"&8February 2023

WJR22-003

WJR22-003 Rio Chama, 1/4 mi. above Archuleta Corral

Sample Date: 8/16/22 Relative

Kick Sample Abundance

Taxon n N/m2 (%)

TURBELLARIA

Polycelis coronata 3 3.00 0.30

NEMATODA

OLIGOCHAETA

Enchytraeidae 3 3.00 0.30

Tubificidae with hair chaetae 9 9.00 0.90

Tubificidae w/o hair chaetae 9 9.00 0.90

EPHEMEROPTERA

Ameletus sp. 15 15.00 1.51

Baetis tricaudatus 54 54.00 5.43

Drunella doddsi 3 3.00 0.30

Drunella grandis 264 264.00 26.53

Ecdyonurus criddlei 9 9.00 0.90

Epeorus longimanus

Ephemerella sp.

Ephemerella tibialis 18 18.00 1.81

Rhithrogena sp. 177 177.00 17.79

PLECOPTERA

Amphinemura banksi

Capniidae

Chloroperlidae

Diura knowltoni

Hesperoperla pacifica

Isogenoides sp. 15 15.00 1.51

Megarcys signata

Perlodidae

Pteronarcella badia

Skwala americana

Sweltsa sp. 9 9.00 0.90

TRICHOPTERA

Agapetus boulderensis 75 75.00 7.54

Arctopsyche grandis 9 9.00 0.90

Brachycentrus americanus 3 3.00 0.30

Brachycentrus occidentalis 12 12.00 1.21

Glossosoma sp.

Lepidostoma sp. 33 33.00 3.32

Oligophlebodes minutus 51 51.00 5.13

Rhyacophila brunnea group

COLEOPTERA

Heterlimnius corpulentus 9 9.00 0.90

Optioservus sp. 57 57.00 5.73

DIPTERA

Antocha sp. 3 3.00 0.30

Atherix pachypus

Brillia sp.

Ceratopogonidae

Clinocera sp.

Conchapelopia sp. 3 3.00 0.30

Diamesa sp.

Dicranota sp. 12 12.00 1.21

Eukiefferiella sp. 3 3.00 0.30

Hexatoma sp. 5 5.00 0.50

Hydrobaenus sp.

Micropsectra sp. 78 78.00 7.84

Odontomesa sp.

Orthocladius sp. 15 15.00 1.51

Pagastia sp.

Paratendipes sp. 15 15.00 1.51

Pericoma/Telmatoscopus sp. 3 3.00 0.30

Polypedilum sp.

Ptychoptera sp.

Radotanypus sp. 3 3.00 0.30

Rheocricotopus sp. 6 6.00 0.60

Simulium sp. 6 6.00 0.60

Stempellinella sp.

Tipula sp.

Tvetenia sp. 6 6.00 0.60

BIVALVIA

Pisidium sp.

Totals: 995 995.00 100.00

Total Density (N/m2) 995

Total Number of Taxa 34

Diversity (d) 3.76

WJR22-003 Rio Chama, 1/4 mi. above Archuleta Corral

Community Metrics

Total Density (N/m2) 995

Diversity (d) 3.76

Total Number of Taxa 34

No. EPT taxa 15

No. Ephemeroptera taxa 7

No. Plecoptera taxa 2

No. Trichoptera taxa 6

% EPT 75.08

% Ephemeroptera 54.27

No. Intolerant taxa 16

% Tolerant Organisms 3.92

% Dominant Taxon 26.53

HBI 1.95

BCI 4.29

% Filterers 3.02

% Scrapers 36.48

% Predators 4.72

% Shredders 4.22

No. Clinger taxa 16

% Clingers 72.36

No. Diptera taxa 13

No. Chironomidae taxa 8

% Diptera 15.88

% Chironomidae 12.96

% Tribe Tanytarsini 7.84

% Heptageniidae 18.69

No. Metal Intolerant species 4

No. WRNF Intolerant species 5

Relative Abundance by Order

TURBELLARIA 0.30

NEMATODA 0.00

OLIGOCHAETA 2.11

EPHEMEROPTERA 54.27

PLECOPTERA 2.41

TRICHOPTERA 18.39

COLEOPTERA 6.63

DIPTERA 15.88

BIVALVIA 0.00

Totals: 100.00

Density by Order

TURBELLARIA 3

NEMATODA 0

OLIGOCHAETA 21

EPHEMEROPTERA 540

PLECOPTERA 24

TRICHOPTERA 183

COLEOPTERA 66

DIPTERA 158

BIVALVIA 0

Totals: 995

&8&A &"Arial,Italic"&8USFS Rio Grande NF 2022

&"Arial,Italic"&8Aquatics Associates, Inc. &"Arial,Italic"&8February 2023

WJR22-004

WJR22-004 Rio Chama, 1/4 mi. above Archuleta Corral - duplicate

Sample Date: 8/16/22 Relative

Kick Sample Abundance

Taxon n N/m2 (%)

TURBELLARIA

Polycelis coronata

NEMATODA

OLIGOCHAETA

Enchytraeidae

Tubificidae with hair chaetae 30 30.00 1.79

Tubificidae w/o hair chaetae 60 60.00 3.58

EPHEMEROPTERA

Ameletus sp. 55 55.00 3.28

Baetis tricaudatus 50 50.00 2.99

Drunella doddsi 20 20.00 1.19

Drunella grandis 470 470.00 28.06

Ecdyonurus criddlei 10 10.00 0.60

Epeorus longimanus

Ephemerella sp.

Ephemerella tibialis 10 10.00 0.60

Rhithrogena sp. 180 180.00 10.75

PLECOPTERA

Amphinemura banksi

Capniidae 5 5.00 0.30

Chloroperlidae

Diura knowltoni 5 5.00 0.30

Hesperoperla pacifica

Isogenoides sp. 5 5.00 0.30

Megarcys signata

Perlodidae

Pteronarcella badia 5 5.00 0.30

Skwala americana 5 5.00 0.30

Sweltsa sp. 5 5.00 0.30

TRICHOPTERA

Agapetus boulderensis 5 5.00 0.30

Arctopsyche grandis 10 10.00 0.60

Brachycentrus americanus

Brachycentrus occidentalis 65 65.00 3.88

Glossosoma sp.

Lepidostoma sp. 150 150.00 8.96

Oligophlebodes minutus 205 205.00 12.24

Rhyacophila brunnea group

COLEOPTERA

Heterlimnius corpulentus 5 5.00 0.30

Optioservus sp. 100 100.00 5.97

DIPTERA

Antocha sp.

Atherix pachypus

Brillia sp.

Ceratopogonidae 10 10.00 0.60

Clinocera sp. 5 5.00 0.30

Conchapelopia sp.

Diamesa sp. 5 5.00 0.30

Dicranota sp.

Eukiefferiella sp.

Hexatoma sp. 25 25.00 1.49

Hydrobaenus sp.

Micropsectra sp.

Odontomesa sp. 5 5.00 0.30

Orthocladius sp.

Pagastia sp.

Paratendipes sp.

Pericoma/Telmatoscopus sp. 15 15.00 0.90

Polypedilum sp. 15 15.00 0.90

Ptychoptera sp.

Radotanypus sp.

Rheocricotopus sp. 5 5.00 0.30

Simulium sp. 115 115.00 6.87

Stempellinella sp. 5 5.00 0.30

Tipula sp.

Tvetenia sp. 5 5.00 0.30

BIVALVIA

Pisidium sp. 10 10.00 0.60

Totals: 1675 1675.00 100.00

Total Density (N/m2) 1675

Total Number of Taxa 34

Diversity (d) 3.68

WJR22-004 Rio Chama, 1/4 mi. above Archuleta Corral - duplicate

Community Metrics

Total Density (N/m2) 1675

Diversity (d) 3.68

Total Number of Taxa 34

No. EPT taxa 18

No. Ephemeroptera taxa 7

No. Plecoptera taxa 6

No. Trichoptera taxa 5

% EPT 75.22

% Ephemeroptera 47.46

No. Intolerant taxa 19

% Tolerant Organisms 5.97

% Dominant Taxon 28.06

HBI 1.94

BCI 4.11

% Filterers 11.94

% Scrapers 30.75

% Predators 3.28

% Shredders 11.04

No. Clinger taxa 19

% Clingers 74.03

No. Diptera taxa 11

No. Chironomidae taxa 6

% Diptera 12.54

% Chironomidae 2.39

% Tribe Tanytarsini 0.30

% Heptageniidae 11.34

No. Metal Intolerant species 5

No. WRNF Intolerant species 5

Relative Abundance by Order

TURBELLARIA 0.00

NEMATODA 0.00

OLIGOCHAETA 5.37

EPHEMEROPTERA 47.46

PLECOPTERA 1.79

TRICHOPTERA 25.97

COLEOPTERA 6.27

DIPTERA 12.54

BIVALVIA 0.60

Totals: 100.00

Density by Order

TURBELLARIA 0

NEMATODA 0

OLIGOCHAETA 90

EPHEMEROPTERA 795

PLECOPTERA 30

TRICHOPTERA 435

COLEOPTERA 105

DIPTERA 210

BIVALVIA 10

Totals: 1675

&8&A &"Arial,Italic"&8USFS Rio Grande NF 2022

&"Arial,Italic"&8Aquatics Associates, Inc. &"Arial,Italic"&8February 2023 species list 2022

USFS Rio Grande 2022 this list is specific to USFS Rio Grande 2022 samples red = new taxa (n=1) vs USFS-WRNF samples blue = name update

Station

Sample Date hbi bci for B-IBI calcs extra metrics for WRNF

Taxon chiron tvalue FFG * clinger t value I=intolerant metal intol WRNF intol

TURBELLARIA

Polycelis coronata 1 OM 10

NEMATODA 5 PA 10

OLIGOCHAETA

Enchytraeidae 10 10

Tubificidae with hair chaetae 10 10

Tubificidae w/o hair chaetae 10 10

EPHEMEROPTERA

Ameletus sp. 0 4.4

Baetis tricaudatus 5 6.7 Baetidae

Drunella doddsi 0 SC cl 0.4 I MI wrnf-I

Drunella grandis 0 cl 2.2 I wrnf-I

Ecdyonurus criddlei 2 SH cl 4.4 Heptageniidae previously Nixe criddlei

Epeorus longimanus 0 SC cl 1.9 I Heptageniidae MI

Ephemerella sp. 1 cl 4.4

Ephemerella tibialis 2 cl 4.4

Rhithrogena sp. 0 SC cl 1.9 I Heptageniidae MI wrnf-I

PLECOPTERA

Amphinemura banksi 2 SH 0.6

Capniidae 1 SH 3

Chloroperlidae 1 PR cl 2.2

Diura knowltoni 2 SC cl 2.2

Hesperoperla pacifica 1 PR cl 1.7

Isogenoides sp. 2 PR cl 2.2

Megarcys signata 2 PR cl 2.2

Perlodidae 2 SH cl 4.4

Pteronarcella badia 0 SH cl 2.2

Skwala americana 2 PR cl 1.7 I MI

Sweltsa sp. 1 PR cl 2.2 I MI

TRICHOPTERA

Agapetus boulderensis 0 SC cl 3

Arctopsyche grandis 2 FC cl 1.7 wrnf-1

Brachycentrus americanus 1 FC cl 2.2

Brachycentrus occidentalis 1 FC cl 2.2

Glossosoma sp. 0 SC cl 2.2

Lepidostoma sp. 1 SH 1.7 wrnf-I

Oligophlebodes minutus 1 SC cl 2.2

Rhyacophila brunnea group 0 PR cl 1.7 I MI wrnf-I

COLEOPTERA

Heterlimnius corpulentus 4 cl 10

Optioservus sp. 4 SC cl 10

DIPTERA

Antocha sp. 3 cl 2.2

Atherix pachypus 2 PR 2.2

Brillia sp. x 5 SH 10

Ceratopogonidae 6 PR 10

Clinocera sp. 6 PR cl 10

Conchapelopia sp. x 6 PR 10 new Rio Grande 2022- t= 6, PR, sprawler

Diamesa sp. x 2 10

Dicranota sp. 3 PR 2.2

Eukiefferiella sp. x 8 10

Hexatoma sp. 2 PR 3.3

Hydrobaenus sp. x 8 SC 10

Micropsectra sp. x 7 10 Tanytarsini

Odontomesa sp. x 4 10

Orthocladius sp. x 6 10

Pagastia sp. x 1 10

Paratendipes sp. x 8 10

Pericoma/Telmatoscopus sp. 4 3.3 I MI

Polypedilum sp. x 6 SH cl 10

Ptychoptera sp. 7 10

Radotanypus sp. x 7 PR 10

Rheocricotopus sp. x 6 10

Simulium sp. 6 FC cl 10

Stempellinella sp. x 4 10 Tanytarsini

Tipula sp. 4 SH 3.3

Tvetenia sp. x 5 10

BIVALVIA

Pisidium sp. 8 FC 10

&8&A

&8Page &P corrected data 2022

USFS Rio Grande 2022 data are corrected for subsampling vial # 1 2 3 4

Station WJR22-001 WJR22-002 WJR22-003 WJR22-004

Sample Date 8/12/22 8/16/22 8/16/22 8/16/22

Taxon

TURBELLARIA

Polycelis coronata 5 3

NEMATODA 1

OLIGOCHAETA

Enchytraeidae 3 3

Tubificidae with hair chaetae 9 30

Tubificidae w/o hair chaetae 2 9 60

EPHEMEROPTERA

Ameletus sp. 15 55

Baetis tricaudatus 26 23 54 50

Drunella doddsi 25 3 20

Drunella grandis 2 264 470

Ecdyonurus criddlei 2 9 10

Epeorus longimanus 21

Ephemerella sp. 1

Ephemerella tibialis 18 10

Rhithrogena sp. 11 177 180

PLECOPTERA

Amphinemura banksi 5

Capniidae 5

Chloroperlidae 1

Diura knowltoni 5

Hesperoperla pacifica 1

Isogenoides sp. 1 15 5

Megarcys signata 2

Perlodidae 1

Pteronarcella badia 8 5 5

Skwala americana 5

Sweltsa sp. 9 5

TRICHOPTERA

Agapetus boulderensis 75 5

Arctopsyche grandis 25 9 10

Brachycentrus americanus 3

Brachycentrus occidentalis 12 65

Glossosoma sp. 2

Lepidostoma sp. 33 150

Oligophlebodes minutus 51 205

Rhyacophila brunnea group 1

COLEOPTERA

Heterlimnius corpulentus 264 9 5

Optioservus sp. 1 57 100

DIPTERA

Antocha sp. 3

Atherix pachypus 1

Brillia sp. 1

Ceratopogonidae 10

Clinocera sp. 5

Conchapelopia sp. 3

Diamesa sp. 5

Dicranota sp. 3 12

Eukiefferiella sp. 2 3

Hexatoma sp. 5 25

Hydrobaenus sp. 1

Micropsectra sp. 1 78

Odontomesa sp. 5

Orthocladius sp. 15

Pagastia sp. 1

Paratendipes sp. 15

Pericoma/Telmatoscopus sp. 3 15

Polypedilum sp. 15

Ptychoptera sp. 7

Radotanypus sp. 3

Rheocricotopus sp. 2 6 5

Simulium sp. 9 6 115

Stempellinella sp. 5

Tipula sp. 1

Tvetenia sp. 2 4 6 5

BIVALVIA

Pisidium sp. 10

Total Organisms 335 139 995 1675

Total Taxa 19 19 34 34

No. grids picked (of 15 total; grids) 15 15 5 3

+100% L&R

&8&A raw data 2022

USFS Rio Grande 2022 raw data vial # 1 2 3 3 4 subsample correction none none x3 100% L&R x5

Station WJR22-001 WJR22-002 WJR22-003 WJR22-003 WJR22-004

Sample Date 8/12/22 8/16/22 8/16/22 8/16/22 8/16/22

Taxon

TURBELLARIA

Polycelis coronata 5 1

NEMATODA 1

OLIGOCHAETA

Enchytraeidae 3 1

Tubificidae with hair chaetae 3 6

Tubificidae w/o hair chaetae 2 3 12

EPHEMEROPTERA

Ameletus sp. 5 11

Baetis tricaudatus 26 23 18 10

Drunella doddsi 25 1 4

Drunella grandis 2 88 94

Ecdyonurus criddlei 2 3 2

Epeorus longimanus 21

Ephemerella sp. 1

Ephemerella tibialis 6 2

Rhithrogena sp. 11 59 36

PLECOPTERA

Amphinemura banksi 5

Capniidae 1

Chloroperlidae 1

Diura knowltoni 1

Hesperoperla pacifica 1

Isogenoides sp. 1 5 1

Megarcys signata 2

Perlodidae 1

Pteronarcella badia 8 5 1

Skwala americana 1

Sweltsa sp. 3 1

TRICHOPTERA

Agapetus boulderensis 25 1

Arctopsyche grandis 25 3 2

Brachycentrus americanus 1

Brachycentrus occidentalis 4 13

Glossosoma sp. 2

Lepidostoma sp. 11 30

Oligophlebodes minutus 17 41

Rhyacophila brunnea group 1

COLEOPTERA

Heterlimnius corpulentus 264 3 1

Optioservus sp. 1 19 20

DIPTERA

Antocha sp. 1

Atherix pachypus 1

Brillia sp. 1

Ceratopogonidae 2

Clinocera sp. 1

Conchapelopia sp. 1 this is new taxon for USFS-WRNF sp list

Diamesa sp. 1

Dicranota sp. 3 4

Eukiefferiella sp. 2 1

Hexatoma sp. 5 5

Hydrobaenus sp. 1

Micropsectra sp. 1 26

Odontomesa sp. 1

Orthocladius sp. 5

Pagastia sp. 1

Paratendipes sp. 5

Pericoma/Telmatoscopus sp. 1 3

Polypedilum sp. 3

Ptychoptera sp. 7

Radotanypus sp. 1

Rheocricotopus sp. 2 2 1

Simulium sp. 9 2 23

Stempellinella sp. 1

Tipula sp. 1

Tvetenia sp. 2 4 2 1

BIVALVIA

Pisidium sp. 2

Total Organisms 335 139 330 5 335

Total Taxa 19 19 33 1 34

No. grids picked (of 15 total; grids) 15 15 5 15 3

100% L&R

&8&A

Colorado Department of Public Health and Environment Water Quality Control Division

Waterbody Name: Rio Grande River Location: mainstem above Rio Grande Reservoir

Predictive Model Results

Multimetric Index Model Results

Non-Insect, percent individuals: 0

Latitude: 37.75453

Longitude: -107.41292

Sample Date: 8/15/2023StationID: RIO-2

Metric Name Metric Value Metric Score

O/E (p>half):

Ephemeroptera + Plecoptera + Trichoptera taxa *: 13

Intolerant, percent taxa *: 55

Increasers, Mid-Elevation, percent individuals: 0

Predator + Shredder taxa: 8

Total taxa: 20

Benthic Macroinvertebrate Bioassessment Report

Reference Status: Not Reference or Degraded

Model Test:

57.5

BenSampID: 420 RepNum: 1

Site Classification: 2

MMI: 40.8

Ephemeroptera + Plecoptera + Trichoptera, no Baetidae, percent individuals:

14.8 18.6

Coleoptera, percent individuals: 0 0

47.6

Intolerant taxa: 11 52.4

Increasers, Mountain Trn, percent individuals: 14.1 19.5

Predator taxa: 6 46.2

Scraper, percent indivduals: 10.9 24.7

Clinger taxa *: 12 60

Non-Insect, percent taxa: 0 0

Sprawler taxa *: 2 0

Increasers, plains, percent individuals: 0 0

Total individuals: 284 ok

* = score (not value) adjusted by Summer temperature or Julian day

Summer Temp: 10.33 JulianDay: 226

Printed: 3/25/2024 1:30:26 PM

Location: mainstem near Hogback Mountain

Non-Insect, percent individuals: 0.9

Latitude: 37.72713

Longitude: -107.01972

Sample Date: 8/15/2023StationID: RIO-4

Ephemeroptera + Plecoptera + Trichoptera taxa *: 15

Intolerant, percent taxa *: 44.1

Increasers, Mid-Elevation, percent individuals: 0.3

Predator + Shredder taxa: 8

Total taxa: 34

62.5

98.2

72.3

BenSampID: 421 RepNum: 1

Site Classification: 1

MMI: 70.7

24.9 34.1

Coleoptera, percent individuals: 27.2 70.7

57.1

Intolerant taxa: 15 0

Increasers, Mountain Trn, percent individuals: 37 0

Predator taxa: 7 0

Scraper, percent indivduals: 25.1 0

98.8

Clinger taxa *: 15 72.1

Non-Insect, percent taxa: 8.8 0

Sprawler taxa *: 8 0

Total individuals: 346 LARGE

Summer Temp: 12.18 JulianDay: 226

Printed: 3/25/2024 1:30:27 PM

Location: mainstem at Palisade Campground

Non-Insect, percent individuals: 0.6

Latitude: 37.75352

Longitude: -106.76815

Sample Date: 8/15/2023StationID: RIO-7

Ephemeroptera + Plecoptera + Trichoptera taxa *: 17

Intolerant, percent taxa *: 46.7

Predator + Shredder taxa: 9

Total taxa: 30

75.2

BenSampID: 422 RepNum: 1

MMI: 63.8

50.6 63.8

Coleoptera, percent individuals: 20.9 0

71.4

Intolerant taxa: 14 66.7

Increasers, Mountain Trn, percent individuals: 35.8 49.5

Predator taxa: 4 30.8

Scraper, percent indivduals: 32.3 73

Clinger taxa *: 16 80

Non-Insect, percent taxa: 6.7 0

Sprawler taxa *: 3 0

Total individuals: 344 LARGE

Summer Temp: 13.4 JulianDay: 226

Printed: 3/25/2024 1:30:27 PM

Location: mainstem at Palisade Campground

Latitude: 37.75352

Longitude: -106.76815

Sample Date: 8/15/2023StationID: RIO-7 DUPE

Ephemeroptera + Plecoptera + Trichoptera taxa *: 9

Intolerant, percent taxa *: 44.4

Predator + Shredder taxa: 5

Total taxa: 18

39.8

BenSampID: 423 RepNum: 1

MMI: 45.1

48.8 61.6

Coleoptera, percent individuals: 10.2 0

42.9

Intolerant taxa: 8 38.1

Increasers, Mountain Trn, percent individuals: 12.9 17.8

Predator taxa: 1 7.7

Scraper, percent indivduals: 43.4 98.2

Clinger taxa *: 11 55

Sprawler taxa *: 4 0

Total individuals: 295 ok

Summer Temp: 13.4 JulianDay: 226

Printed: 3/25/2024 1:30:28 PM

Waterbody Name: Saguache Creek Location: mainstem below confluence of S. Saguache Ck.

Latitude: 38.01642

Longitude: -106.64753

Sample Date: 8/22/2023StationID: SAG-1

Ephemeroptera + Plecoptera + Trichoptera taxa *: 16

Intolerant, percent taxa *: 52.9

Predator + Shredder taxa: 10

Total taxa: 34

66.7

86.8

BenSampID: 424 RepNum: 1

Site Classification: 1

MMI: 72.0

35.3 48.4

Coleoptera, percent individuals: 15.5 40.2

71.4

Intolerant taxa: 18 0

Increasers, Mountain Trn, percent individuals: 33.2 0

Predator taxa: 9 0

Scraper, percent indivduals: 23.3 0

Clinger taxa *: 13 62.5

Sprawler taxa *: 7 0

Total individuals: 343 LARGE

Summer Temp: 11.07 JulianDay: 233

Printed: 3/25/2024 1:30:28 PM rpt_Bioassessment

Aquatic Life Use Attainment

Methodology to Determine Use Attainment for

Rivers and Streams

Policy Statement 10-1

Water Quality Control Commission

4300 Cherry Creek Dr. South Denver Colorado 80246-1530

Approved: August 7, 2017 Expires: December 31, 2020

This page intentionally left blank i

Table of Contents

I. INTRODUCTION

II. COLORADO’S AQUATIC LIFE USES

III. BACKGROUND

IV. BIOASSESSMENT AND BIOLOGICAL THRESHOLDS

V. METHODOLOGY FOR DETERMINING CURRENT

BIOLOGICAL CONDITION

VI. HISTORY OF USE ATTAINMENT DECISIONS BASED ON

BIOLOGICAL INFORMATION

VII. ASSOCIATION BETWEEN AQUATIC LIFE POLICY AND OTHER

WQCC ACTIONS…………………………………………………………………7

VIII. AQUATIC LIFE USE ATTAINMENT: BASIC CONCEPTS

IX. AQUATIC LIFE USE ATTAINMENT: NUMERICAL THRESHOLDS

X. REFERENCES……………………………………………………………………14

XI. APPENDICES

A. MMI FINAL REPORT - RECALIBRATION OF THE COLORADO

MACROINVERTEBRATE MULTI-METRIC INDEX FOR 2017

B. BENTHIC MACROINVERTEBRATE SAMPLING STANDARD OPERATING

PROCEDURES

C. STANDARD OPERATING PROCEDURES FOR LABORATORY

IDENTIFICATION AND ENUMERATION

D. METHODOLOGY FOR DETERMINING BIOLOGICAL CONDITION

E. THRESHOLD DEVELOPMENT - TECHNICAL UNDERPINNINGS

F. BIG RIVER ANALYSIS – DATA AND GRAPHS

ii

List of Tables

Table 1 Aquatic Life Use Thresholds Table 2 Auxiliary Metric Thresholds for Class 1 Waters with MMI

Scores Between the Attainment and Impairment Thresholds Table 3 Criteria for Protection of High Scoring Waters

List of Figures

Figure 1 Flowchart: Comparison with Aquatic Life Thresholds Figure 2 Flowchart: Protection of High Scoring Waters

List of Acronyms and Abbreviations

AAH Administrative Action Hearing

Commission Colorado Water Quality Control Commission

CPW Colorado Parks and Wildlife (formerly known as Colorado Division of Wildlife or CDOW)

CWQCA Colorado Water Quality Control Act

CWA Clean Water Act

Division Colorado Water Quality Control Division

EPA U.S. Environmental Protection Agency

EPT Taxa The number of Ephemeroptera, Plecoptera and Trichoptera genera represented in a macroinvertebrate sample. These genera are generally very sensitive to pollution.

mi2 Square mile

MMI Multi-metric Index

WQCC Water Quality Control Commission

WQCD Water Quality Control Division iii

Definitions

Aquatic Assemblage means a group of interacting species in a given water body, united by habitat and ecology. For example, “fish assemblage” or “benthic macroinvertebrate assemblage.”

Benthic Macroinvertebrates (also macrobenthos) means the animals (without backbones) living on or in the streambed. These animals generally are large enough to be seen by the unaided eye; the size of the smallest organisms in this community is determined operationally by what can be retained by a U.S. Standard No. 30 sieve (28 openings/inch, 0.595-mm openings).

Big Rivers are considered major rivers with a cumulative watershed area exceeding 2700 mi2.

Biological Assessment (or bioassessment) means an evaluation of the biological condition of a water body using biological survey data and other direct measurements of resident biota in surface waters.

Biological Thresholds means numeric values or narrative expressions that describe the expected biological quality of aquatic communities in waters of a given classified aquatic life use. Biological thresholds are based on direct measurement of the aquatic community, including its structure and functions.

Gray Zone means that the biological condition is neither impaired nor in attainment of the use based on Interval and Equivalence tests in which neither hypothesis is rejected. More information, in the form of two auxiliary metrics, are considered before reaching a conclusion about impairment for Class 1 waterbodies.

Metric means a calculated term or enumeration representing some aspect of biological assemblage, function, or other measurable aspect. A multimetric approach combines metrics to provide an integrative assessment of the status of aquatic resources.

AQUATIC LIFE USE ATTAINMENT

METHODOLOGY TO DETERMINE USE ATTAINMENT

FOR RIVERS AND STREAMS

I. INTRODUCTION

Direct measurement and characterization of the health and well-being of the aquatic community in surface water are critical to determining how effectively Colorado is achieving the ultimate goals of the Colorado Water Quality Control Act (“CWQCA”) and the Federal Clean Water Act (“CWA”), which are to restore, maintain, protect, and improve the quality of our water resources.1 To this end, one of the specific policy goals of the CWQCA is the “protection and propagation of wildlife and aquatic life.2” The Federal CWA similarly speaks to the importance of healthy aquatic ecosystems in its often-quoted Congressional declaration, which sets forth the CWA’s key objective - to “restore and maintain the chemical, physical and biological integrity of the Nation’s waters.3” These legislative policy statements highlight the importance of having tools and techniques available to evaluate the current aquatic-life conditions in our surface waters, and to set goals for the future.

This policy document provides the Colorado Water Quality Control Commission’s (“commission”) methodology for determining whether the aquatic life use is attained in rivers and streams. The procedures detailed in this guidance rely upon direct measurement of the aquatic life use rather than on comparing existing water quality to numeric standards for individual pollutants (e.g. copper, zinc, ammonia) set to protect aquatic life.

The commission’s approach to making aquatic life use-attainment decisions has evolved over time. The intent of this policy is to describe the cumulative result of regulatory actions taken by the commission. It is envisioned that as the commission gains experience and takes action on individual use-attainment decisions in the context of Regulation No. 93 “Colorado’s Section 303(d) List of Impaired Waters and Monitoring and Evaluation List” and in considering re-classification of water bodies in rulemaking hearings, this policy document will be revised to reflect those new policy decisions.

The contents of this document have no regulatory effect, serving instead to summarize the commission’s thinking and actions in a single public document. In other words, as opposed to a rule or regulation, this policy statement has no binding effect on the commission, the Water Quality Control Division ("division"), or the regulated community. Moreover, this policy is not intended, and should not be interpreted, to limit any options that may be considered or adopted by the commission in future rulemaking proceedings. Therefore, this policy statement can, and will, be modified over time as warranted by future rulemaking decisions.

II. COLORADO’S AQUATIC LIFE USES

Colorado classifies water bodies for beneficial uses that, along with chemical and physical standards, assure their protection. Colorado has four classifications for waters: water supply, 1 See Colorado Water Quality Control Act, § 25-8-102(2), C.R.S.; Federal Clean Water Act, § 101(a), 33 U.S.C.

§ 1251(a).

2 Colorado Water Quality Control Act at section 25-8-101(2) and Clean Water Act at section 101(a) (2).

3 Federal Clean Water Act at section 101(a), emphasis added.

recreation, agriculture and aquatic life. Colorado’s aquatic life use classifications are assigned to individual water body segments based upon the potential to support that use according to a narrative description in Regulation No. 31 “Basic Standards and Methodologies for Surface Water” at section 31.13:

31.13 STATE USE CLASSIFICATIONS

Waters are classified according to the uses for which they are presently suitable or intended to become suitable. In addition to the classifications, one or more of the qualifying designations described in section 31.13(2), may be appended. Classifications may be established for any state surface waters, except that water in ditches and other manmade conveyance structures shall not be classified.

(1) Classifications

(c) Aquatic Life These surface waters presently support aquatic life uses as described below, or such uses may reasonably be expected in the future due to the suitability of present conditions, or the waters are intended to become suitable for such uses as a goal:

(i) Class I - Cold Water Aquatic Life These are waters that (1) currently are capable of sustaining a wide variety of cold water biota, including sensitive species, or (2) could sustain such biota but for correctable water quality conditions. Waters shall be considered capable of sustaining such biota where physical habitat, water flows or levels, and water quality conditions result in no substantial impairment of the abundance and diversity of species.

(ii) Class 1 - Warm Water Aquatic Life These are waters that (1) currently are capable of sustaining a wide variety of warm water biota, including sensitive species, or (2) could sustain such biota but for correctable water quality conditions. Waters shall be considered capable of sustaining such biota where physical habitat, water flows or levels, and water quality conditions result in no substantial impairment of the abundance and diversity of specifies.

(iii) Class 2- Cold and Warm Water Aquatic Life These are waters that are not capable of sustaining a wide variety of cold or warm water biota, including sensitive species, due to physical habitat, water flows or levels, or uncorrectable water quality conditions that result in substantial impairment of the abundance and diversity of species.

III. BACKGROUND

Historically, Colorado’s aquatic life use classifications have sometimes been difficult to determine for a given water body. The broad categories and the generalized terms in the classification descriptions have led to disagreements and sometimes contentious hearings about the appropriate classification of specific water bodies.

The current effort to refine the aquatic life use classifications and provide a more consistent basis for determining the condition of aquatic life arose from specific issues in Colorado, as well as an increased national focus on biological thresholds. In the late 1990’s, a contentious hearing about the proper classification of the Lower Arkansas River raised awareness of problems with the existing descriptions of the aquatic life use classifications. This coincided with EPA encouragement for States to incorporate biological assessments and biological thresholds as major components of their monitoring and assessment programs. In June 2000, the division established the Aquatic Life Work Group to develop biological assessment methods and biological thresholds, and propose refinements of the aquatic life use classifications.

In 2002, an amendment of the CWQCA (§ 25-8-309) directed the division to study (among other things) the need for refined aquatic life use classifications and a better method with a uniform approach to determine whether a water body had attained its aquatic life use. These subjects were explored by the Aquatic Life Work Group. The result of the CWA Section “309” study was to flesh out the expected condition concept and identify a “Strawman” classification system which contained nine primary aquatic life use categories and 27 possible subcategories and called for voluntary pilot studies to characterize the “expected condition” for candidate sub-categories. However, the pilot studies did not proceed as intended due to a lack of interest, funding, and study sites.

In November of 2004, the commission reviewed the Aquatic Life Work Group’s “expected condition concept” during the Basic Standards Issues Formulation Hearing. At that time, the commission decided not to incorporate the expected condition concept in the 2005 Basic Standards and Methodologies for Surface Water (Regulation #31) Rulemaking Hearing.

Instead, the commission tasked the Aquatic Life Work Group with strengthening the underlying biological data from which the Strawman’s nine principle use classification categories and sub-classifications would be defined. At that time the commission targeted the 2010 Rulemaking Hearing for Basic Standards for the next Strawman iteration.

Coincidentally, the division began to work with the EPA and their contractors to use Colorado’s data to develop bioassessment tools. This effort is described below in Section IV.

Rather than restructuring the existing classification system with potentially numerous ramifications, the division decided to proceed with the more modest step of utilizing bioassessment tools and data to refine how existing classifications are interpreted and applied. This policy represents the first official step to add more specificity to Colorado’s aquatic life use classifications.

IV. BIOASSESSMENT AND BIOLOGICAL THRESHOLDS

Bioassessment is a quantitative measure of the biological condition of the resident aquatic community. A biological threshold is the establishment of numeric criteria against which the current biological condition can be evaluated. Each of these regulatory concepts – biological assessment and biological thresholds – are defined briefly in the Definitions section, and then discussed in more detail in Section IV subsection A.

A. Bioassessment Tools

Aquatic communities are an association of interacting populations of aquatic organisms in a given waterbody or habitat (EPA 1991). They provide valuable information regarding the overall biological integrity of a given waterbody. These organisms are capable of integrating the effects of stressors over time; thus, they can provide a broad ecological measure of fluctuating environmental conditions (EPA 1999). Bioassessments provide the means to evaluate biological condition in relation to the goal or expectation, such as designated use support.

Several biological assemblages are available for study including periphyton (attached algae), benthic macroinvertebrates and fish, each of which responds somewhat differently to the suite of anthropogenic stressors. The decision to rely exclusively on the benthic macroinvertebrates assemblage was based on community characteristics and practical considerations. The combination of short life spans, limited migration patterns, representation in most Colorado habitats, and ease of collection make macroinvertebrates the best single assemblage for bioassessment.

Within the benthic macroinvertebrate assemblage, metrics are selected that represent some measureable aspect of the community structure and function. These measurements are grouped into five metric categories: taxa richness, composition, pollution tolerance, functional feeding groups, and habit (mode of locomotion). Combining metrics from these categories into a multi-metric index transforms taxonomic identifications and individual counts into a unitless score that ranges from 0-100.

Choosing metrics that are sensitive to stressors yields an index that defines the health, or the biological condition, of the aquatic community. A bioassessment tool of this kind is a powerful basis for a direct assessment of aquatic communities that can be used to reach conclusions about attainment of the aquatic life use.

B. Colorado’s Multi-Metric Index (MMI) Bioassessment Tool

The division, with assistance from EPA and its contractors, has developed a multi-metric bioassessment tool for Colorado that is composed of separate indices calibrated to respond to stressors affecting aquatic communities in one of the three analytically defined Biotypes.4

Multi-metric indices were then calibrated for each Biotype. Each index is composed of several metrics selected to represent categories of community characteristics including richness, composition, functional feeding group, habit (mode of locomotion), and pollution tolerance. Metrics were chosen on the basis of their ability to discriminate between reference and stressed sites, represent multiple metric categories, are ecologically meaningful, and are not redundant with other metrics in the index. See Appendix A for details.

Because of this metric selection process, the metrics used in the MMI vary in their ability to detect or diagnose specific types of stress. The MMI is designed to detect environmental stresses that result in alteration of the biological community. No specific stressors are identified because the intent is to have a generalized tool that responds to a wide range of potential stressors. In other words, the MMI tool cannot determine if the stressor is a specific pollutant, pollution or habitat limitation (including flow). Once impairment is identified, however, other tools are available to identify the likely cause of impairment.

4 A Biotype is an aggregation of macrobenthos sites that have similar community composition. Environmental attributes (elevation, stream slope and ecoregion) common to sites within each of the Biotypes can be used to predict membership of a new site.

V. METHODOLOGY FOR DETERMINING CURRENT BIOLOGICAL CONDITION

Determining biological condition involves the steps of calculating the MMI for the appropriate Biotype and comparing the MMI score to a threshold.

To calculate an MMI a representative macroinvertebrate sample is collected from the appropriate habitat(s). Standardized procedures for collecting macroinvertebrates are in Appendix B. Field sampling is typically followed by preservation, laboratory identification and enumeration, and entry into a biological database capable of calculating the MMI. See Appendices C and D for details.

VI. HISTORY OF USE ATTAINMENT DECISIONS BASED ON BIOLOGICAL

INFORMATION

Direct measurement and characterization of the health and well-being of the aquatic community in surface water is critical to determine whether or not the aquatic life use is attained at a given site. Historically, Colorado has used biological information to make attainment decisions, even though no specific methods of assessment or thresholds were set.

This section describes the history of such decisions.

A. Impaired Waters Listing Decisions

In 1998, the Colorado List of Impaired Waters included three segments found to be impaired for aquatic life. The associated listing methodology explained the protocol for reaching those decisions:

Biological assessments by the Colorado Division of Wildlife (CDOW) were utilized in developing the List. These consist of fish surveys performed by CDOW staff using both seining and electrofishing. The results of these assessments were compared with the Standards and Classification System in the following manner. For segments that are designated as Aquatic Life Class 1, evidence of a decline over time from a healthy and diverse fish community or the absence of a Species of Critical Concern5 constitutes an impairment of the use. For segments that are designated as Aquatic Life Class 2, evidence of significant reduction of the species composition of a fish community over time constitutes an impairment of the use. The Division limited the time frame for comparison of fish communities as shown by fish surveys, to only the late 1970’s (when aquatic life classes were established) through more recent conditions.

The requirement for a Section 303(d) List in 2000 was suspended by EPA, and no List of Impaired Waters was compiled. The 2002 303(d) List included six waters with an impaired aquatic life use. Decisions about impairment were based on the following narrative that appeared in the 2002 Listing Methodology:

B. IMPAIRMENT OF NARRATIVE STANDARDS AND CLASSIFIED USES

Impairment of narrative standards and classified uses may be supported by chemical data and/or information generated by biological and/or physical assessments. In

5 Species of Critical Concern includes native fish species observed to be in decline and rare in abundance or limited in distribution (as identified by CPW in the Inventory and Status of South Platte River Native Fishes in Colorado, CPW, 1997).

instances where a determination of impairment is based solely upon biological and/or physical assessments, such assessments must provide clear and convincing evidence of non-attainment. For aquatic life uses, as previously referenced, the WQCD will generally consider impairment of narrative standards and classified uses to be demonstrated when either the physical/habitat data or biological community metrics reflect a condition that is significantly less than reference condition. When such data do not indicate specific pollutant(s) causing non-attainment, the WQCD may place the segment on the M&E List for further study.

In 2004, the Section 303(d) List was promulgated as Regulation No. 93, and the Monitoring and Evaluation List became Regulation No. 94. As in 2002, a separate Listing Methodology document was developed. The 2004 Section 303(d) List included six waters with an impaired aquatic life use. The 2004 Listing Methodology section regarding decisions of impairment based on biological information is essentially the same as 2002, but with the addition of the concept of “expected condition,” as provided below.

3. Impairment of Narrative Standards and Classified Uses data and/or information generated by biological and/or physical…