James River Chlorophyll Study Status update to the SAG

Anne SchlegelVA DEQ

November 16, 2015

Two Discussion Topics

Presentations at the recent SAP meetingGlance at a couple of the “take homes” from 2

of the presentations (Claire Buchanan and Clifton Bell) Feedback, suggested improvements or different

approach?Documents and presentations sent or posted

on-lineSurvey

“Decision Tree”Survey questions

“Comments on September 2015 Empirical Relations Report” Clifton Bell and Will Hunley

“Effects-based methods pursued by SAP represent a major improvement in defensibility over past efforts to derive CHLa targets.”

“Combined probability approach represents significant advancement over past efforts”

“Incorporates a great deal of new James-specific data and experimental results”

“Also uses wider literature”“Significant advancement in linkages to harmful algal

effects”CocholodiniumMicrocystisMicrocystin

Recommended additions to the Empirical Relations Report“More background on limitations of past efforts”“More background on study drivers, rationale behind

approach”“Somewhat more detailed explanation of combined

probability methods with example”

“Comments on September 2015 Empirical Relations Report” Clifton Bell and Will Hunley

Agreement, Recommended Adjustmentsto CHLa Ranges (From Bell and Hunley)

5

Reference-based approachCombinations of DIN, PO4 and Secchi characterize

phytoplankton conditions: reference to degraded “Reference conditions are home to biological communities with

“good” integrity”

Uses Bay-wide, long-term data to Develop relationships between CHLa means and their upper

limitsDevelop relationship between CHLa mean and % exceedence

of a known upper limit or thresholdThen used these relationships to….

Determine expected upper limit (e.g. 90th %ile) of CHLa distribution when seasonal JR criteria are expressed as geometric means

Determine % of samples that can be expected to exceed a threshold (e.g. 90th %ile) for a given CHLa seasonal mean

“From Programmatic Goals to Chlorophyll a Criteria” Claire Buchanan

“From Programmatic Goals to Chlorophyll a Criteria” Claire Buchanan

“From Programmatic Goals to Chlorophyll a Criteria” Claire Buchanan

“We know the central tendencies that protect desirable Ches. Bay phytoplankton….these do not include the current JR criteria…”

SAP Survey

James River Chlorophyll SAP SurveyPurpose: Help to ensure that DEQ understands

each SAP member’s opinion about the protectiveness of the current JR chlorophyll criteria

“Instructions” to SAP membersConsider all project work to inform their opinions Review “Decision Tree” – provides framework for

considering the different parts of the standardSurvey results will be included with other project

products (e.g. reports, data, STAC review) in DEQ’s internal analysis

Criteria Protectiveness “Decision Tree”

Are the current criteria, as they appear in the WQS, protective of the aquatic life designated use? Is the magnitude protective? Is the duration protective? Is the frequency protective?

Yes to everything

Are the criteria over-protective?

Yes

What needs to be changed?

No

No

Keep the criteria the same

Criteria Protectiveness Decision Tree

Magnitude?

Duration?

Frequency?

What needs to be changed?

Criteria Protectiveness Decision Tree

Should we be using a different statistic? Instead of a mean, should we be using a median? Do we care more about protecting central tendency or preventing higher-end extremes?

If we decide to stick with the current statistic, do the values need to be lowered or raised?

Should magnitude be dependent on observed salinity rather than Bay segmentation scheme?

Magnitude?

Duration?

Frequency?

What needs to be changed?

Criteria Protectiveness Decision Tree

Should we be assessing individual observations instead of temporally-aggregated data?

Would a monthly or annual mean be superior to a seasonal mean?

Magnitude?

Duration?

Frequency?

What needs to be changed?

Criteria Protectiveness Decision Tree

Should we change how we interpolate the data?

Should the spatial dimension be areal or volumetric?

Should we be using a different reference curve or exceedence percentage rule?

Should the assessment window be lengthened or shortened (6 years or 2 years instead of 3 years)?

Magnitude?

Duration?

Frequency?

What needs to be changed?

James River Chlorophyll SAP SurveyAre the current chlorophyll criteria under- OR over-

protective in any season-segment with respect to magnitude and duration?Current statistic (geomean)Criteria valueCriteria durationOtherProvide reasoning for opinions and suggest alternatives if

appropriateAre the current criteria over- OR under-protective in

any season-segment with respect to frequency?Method for determining frequency of exceedence Three year assessment windowDEQ’s current monitoring programOtherProvide reasoning for opinions and suggest alternatives if

appropriate

James River Chlorophyll SAP Survey Is the proposed assessment methodology over-

OR under-protective of the James River aquatic life designated use?Method for determining frequency of exceedenceSix year assessment windowOtherProvide reasoning and suggest alternatives if appropriate

Any other recommendations to make to DEQ?

So what is DEQ doing with all of this information?

The feedback provided and the survey results will be included along with all other project products (e.g. reports, data, STAC review) in DEQ’s internal analysis