Implementation of the USEPA Methods Update Rule to

40 CFR :Field Filtration & Preservation

Gerard Marzec, James Broderick and Karen Moore, PhD

NYC Department of Environmental Protection

IntroductionIntroduction

USEPA Method Update Rule (MUR)USEPA Method Update Rule (MUR) Implementation of field filtrationImplementation of field filtration Statistical design of side-by-side Statistical design of side-by-side

sampling comparisonsampling comparison Future work – data analysisFuture work – data analysis

USEPA Methods Update RuleUSEPA Methods Update Rule Federal Register: March 12, 2007 (Volume 72, Federal Register: March 12, 2007 (Volume 72,

Number 47) [Pages 11199-11249]Number 47) [Pages 11199-11249] 40 CFR Parts 122, 40 CFR Parts 122, 136136, 141, 143, 430, 455, and , 141, 143, 430, 455, and

465. 465. This rule modifies the testing procedures This rule modifies the testing procedures

approved for analysis and sampling under the approved for analysis and sampling under the Clean Water Act and Safe Drinking Water Act. Clean Water Act and Safe Drinking Water Act.

The Clean Water Act changes adopted in this final The Clean Water Act changes adopted in this final rule fall into several categories. Our investigation rule fall into several categories. Our investigation focuses on the following:focuses on the following:– changes to sample collection, preservation, and holding changes to sample collection, preservation, and holding

time requirements. time requirements.

Methods Update Rule – Sample Methods Update Rule – Sample CollectionCollection

38. The rule revises Table II (Required Containers, 38. The rule revises Table II (Required Containers, Preservation Techniques, and Holding Times) and Preservation Techniques, and Holding Times) and the footnotes to the table at 40 CFR 136.3(e). The the footnotes to the table at 40 CFR 136.3(e). The table and footnotes specify approved sampling, table and footnotes specify approved sampling, preservation, and holding time requirements for preservation, and holding time requirements for the methods approved for compliance monitoring. the methods approved for compliance monitoring.

N. Revisions to 40 CFR Part 136, Table IIN. Revisions to 40 CFR Part 136, Table II – EPA revised footnotes 2 and 7 to add language to make EPA revised footnotes 2 and 7 to add language to make

more clear that more clear that preservation must be within 15 minutes preservation must be within 15 minutes after collectionafter collection of a grab sample, a composite sample, or of a grab sample, a composite sample, or an aliquot split from a composite sample collected an aliquot split from a composite sample collected automatically over time. automatically over time.

Wording ChangeWording Change

““Immediately” became “15 minutes”Immediately” became “15 minutes” Tests in Table II where “15 minutes” Tests in Table II where “15 minutes”

is stated as the “Maximum Holding is stated as the “Maximum Holding Time”Time”– Total Chlorine ResidualTotal Chlorine Residual– Hydrogen Ion (pH)Hydrogen Ion (pH)– Orthophosphate, “filter within…”Orthophosphate, “filter within…”– Oxygen, dissolved probeOxygen, dissolved probe– SulfiteSulfite

Footnotes to Table IIFootnotes to Table II Note 2 (applies to entire preservation Note 2 (applies to entire preservation

column): Except where noted in this column): Except where noted in this Table II and the method for the parameter, Table II and the method for the parameter, preserve each grab sample within 15 preserve each grab sample within 15 minutes of collectionminutes of collection. .

Note 7 (applies to all rows in the Note 7 (applies to all rows in the subheading Metals): subheading Metals): For dissolved metals, For dissolved metals, filter grab samples within 15 minutes of filter grab samples within 15 minutes of collection and before adding collection and before adding preservatives.preservatives.

Provisions are also stated for composite Provisions are also stated for composite samplessamples

Affected DEP AnalytesAffected DEP Analytes Historically Watershed DEP Laboratories have Historically Watershed DEP Laboratories have

filtered and preserved at the laboratory, upon filtered and preserved at the laboratory, upon return from field sampling.return from field sampling.

Preservation applied to metals, organic carbon, Preservation applied to metals, organic carbon, total phosphorus/nitrogentotal phosphorus/nitrogen

Filtration applied to nutrients analyzed by optical Filtration applied to nutrients analyzed by optical methods (ammonia, SRP, TDP, TDN, NO2+NO3), methods (ammonia, SRP, TDP, TDN, NO2+NO3), dissolved carbon, dissolved major cations (Ca, K, dissolved carbon, dissolved major cations (Ca, K, Mg, and Na), and dissolved Al).Mg, and Na), and dissolved Al).

Now all of this work must be conducted in the Now all of this work must be conducted in the field.field.

What is a compliance sample?What is a compliance sample?

Rule states “for compliance samples” Rule states “for compliance samples” under the Clean Water Act.under the Clean Water Act.

Obviously affects SPDES samplesObviously affects SPDES samples Does it affect all other samples that Does it affect all other samples that

DEP collects and analyzes?DEP collects and analyzes?

NYS Public Health Law 502NYS Public Health Law 502 Excerpts from LawExcerpts from Law

– 1. "Environmental Laboratory" is any facility that 1. "Environmental Laboratory" is any facility that examines or is available for the examination of samples examines or is available for the examination of samples or specimens.or specimens.

– 2. No environmental laboratory may perform any 2. No environmental laboratory may perform any examination on samples collected in the State of New examination on samples collected in the State of New York for which the commissioner issues a certificate of York for which the commissioner issues a certificate of approval for such examination unless the laboratory has approval for such examination unless the laboratory has been issued such certificate of approval. been issued such certificate of approval.

As a result, any sample collected in the State of New York As a result, any sample collected in the State of New York must comply with the Rules of the ELAP Program and is must comply with the Rules of the ELAP Program and is thus a “compliance sample”. Additionally, much of our data thus a “compliance sample”. Additionally, much of our data is reported directly (e.g., DMR) or indirectly (Filtration is reported directly (e.g., DMR) or indirectly (Filtration Avoidance Deliverable reports) to EPA and NYS. Avoidance Deliverable reports) to EPA and NYS.

Failure to comply with subdivision 2 of this law is Failure to comply with subdivision 2 of this law is considered a misdemeanor!considered a misdemeanor!

The Need for ChangeThe Need for Change

With the regulatory changes stated in the With the regulatory changes stated in the MUR, it seemed that DEP had no choice MUR, it seemed that DEP had no choice but to change.but to change.

With that decision made, we embarked on With that decision made, we embarked on a collaborative change effort, including a collaborative change effort, including staff from Management, Field, Laboratory, staff from Management, Field, Laboratory, Health & Safety, Quality Assurance and Health & Safety, Quality Assurance and Science & Research.Science & Research.

The objective: Determine safe, efficient, The objective: Determine safe, efficient, technically appropriate procedures and technically appropriate procedures and equipment to meet the requirements.equipment to meet the requirements.

Approach to implementation of field filtrationApproach to implementation of field filtration

Brain stormBrain storm Test equipment and procedures for Test equipment and procedures for

general acceptance (time, pressure, general acceptance (time, pressure, battery life, flow rates, safety)battery life, flow rates, safety)

Test equipment for contaminationTest equipment for contamination Implement the changeImplement the change Evaluate the long term effect of the Evaluate the long term effect of the

changechange

Field Filtration ConsiderationsField Filtration Considerations One filtration procedure if possible for all One filtration procedure if possible for all

analytes and sample types.analytes and sample types. Filtration procedure needs to be practical Filtration procedure needs to be practical

(able to be performed on a boat with (able to be performed on a boat with limited space during a rain event).limited space during a rain event).

Must address potentially high sediment in Must address potentially high sediment in some watersheds (select filter with best some watersheds (select filter with best surface area).surface area).

Procedures must be safe (use of acids in Procedures must be safe (use of acids in the field).the field).

Avoid rushing or overburdening field staff. Avoid rushing or overburdening field staff. Standardize all of our procedures (4 Standardize all of our procedures (4

lab/field groups).lab/field groups).

Method elementsMethod elements Peristaltic pump does not Peristaltic pump does not

come in contact with come in contact with sample, is light weight and sample, is light weight and durable for field use.durable for field use.

Pump tubing is PVC that Pump tubing is PVC that can be rinsed and re-used. can be rinsed and re-used.

Groundwater capsule filter Groundwater capsule filter (0.45µm) with 700 cm(0.45µm) with 700 cm22 surface area selectedsurface area selected

Samples from streams can Samples from streams can be filtered on the stream be filtered on the stream bank or from a collection bank or from a collection bottle at the truck.bottle at the truck.

Samples from reservoirs Samples from reservoirs are filtered directly from are filtered directly from the Van Dorn sampler.the Van Dorn sampler.

Method implementationMethod implementation

Successful and relatively trouble-freeSuccessful and relatively trouble-free- equipment performance - equipment performance

acceptable in streams, acceptable in streams, on boats, and in facilitieson boats, and in facilities

- capsule filters (1/sample)- capsule filters (1/sample)do not clog do not clog

- no contamination problems- no contamination problems- time requirement met- time requirement met

Field-Lab Filtration ComparisonField-Lab Filtration Comparison Estimate sample size Estimate sample size

needed to show needed to show

filtration and filtration and preservation preservation

method differencesmethod differences– Use of existing dataUse of existing data– Statistical testsStatistical tests– ResultsResults

Sample-size estimatesSample-size estimates MethodMethod

2002-2006 data2002-2006 data– over 27,000 samplesover 27,000 samples– data separated by watershed and by sample data separated by watershed and by sample

typetype– data review essentialdata review essential

Used 2 sample t-testUsed 2 sample t-test– Normalized data via log or other Normalized data via log or other

transformationtransformation– Applied significance level of alpha=0.05 and a Applied significance level of alpha=0.05 and a

power of 0.9 and analyte-dependent power of 0.9 and analyte-dependent magnitude of difference (effect level)magnitude of difference (effect level)

– So why are we interested in power?So why are we interested in power?

Why are we interested in power?Why are we interested in power?

In a side-by-side comparison, the In a side-by-side comparison, the number of samples required for number of samples required for power=0.9 will give you the ability to power=0.9 will give you the ability to detect differences 90% of time.detect differences 90% of time.

Results…Results…

West of Hudson StreamsWest of Hudson Streams(2002 – 2006; alpha =0.05, power =0.9)(2002 – 2006; alpha =0.05, power =0.9)

Data Actual Actual Actual Number of

Analyte N Used Transf. Mean Std Dev Min Diff Samples needed

Cl- 3967 All x0.333 7.5 7.7 0.25 20

DOC 4022 All -1/x0.5 1.5 0.73 100 60

Ca 3300 All ln x 5.8 3.0 1.4 61

K 3252 >ND ln x 0.52 0.34 1.4 80

Mg 3300 All ln x 1.2 0.62 1.4 59

Na 3246 >ND ln x 4.3 4.3 1.8 65

NH3 150 >0.03 -1/x 0.06 0.04 0.25 65

NO3+NO2 3343 >ND ln x 0.48 0.38 1.7 56

Silica 3786 All None 3.6 1.1 0.70 50

SO4 4083 All -1/x 6.1 1.7 33 34

SRP 4421 >ND ln x 9.1 15 1.5 71

TDN 4309 All ln x 0.39 0.27 1.2 82

TDP 3204 >ND ln x 11 8.6 1.5 42

Sample-size estimatesSample-size estimates side-by-side sampling factorsside-by-side sampling factors

The samples need to capture the natural The samples need to capture the natural variability in the systemvariability in the system– Streams need coverage of base/storm flowStreams need coverage of base/storm flow– Reservoirs need coverage through the year Reservoirs need coverage through the year

with emphasis on sampling for redox sensitive with emphasis on sampling for redox sensitive analytes during stratificationanalytes during stratification

Filtration blanks will demonstrate Filtration blanks will demonstrate differences at the low end. Need to differences at the low end. Need to capture high end of data range.capture high end of data range.

Work to be done…Work to be done…

Data analysis on samples currently Data analysis on samples currently being collectedbeing collected

Are there both practical and Are there both practical and statistically significant differences?statistically significant differences?

Can a relationship be established so Can a relationship be established so that a correction factor can be that a correction factor can be determined?determined?

Statistically significant vs. practical Statistically significant vs. practical differencesdifferences

Compared dissolved vs total cations Compared dissolved vs total cations where data were availablewhere data were available

Used Wilcoxon signed-rank test and Used Wilcoxon signed-rank test and partitioned data into EOH and WOH partitioned data into EOH and WOH reservoirsreservoirs

The effect level chosen keeps it real!The effect level chosen keeps it real! Results…Results…

WOH ReservoirsWOH Reservoirs

Median ofCation N Median Difference p-value

Ca-Filtered 2096 5.06 0.02 <.0001Ca 2076 5.15Mg-Filtered 2405 1 0.02 <.0001Mg 2385 1.07Na-Filtered 601 3.2 0.04 <.0001Na 581 3.23K-Filtered 931 0.39 0.05 <.0001K 911 0.46

Establish relation between methodsEstablish relation between methods

Can a correction factor be determined?Can a correction factor be determined? Sample size estimates alone may not be Sample size estimates alone may not be

enough to determine a relation/correction enough to determine a relation/correction factor.factor.

A method comparison for 2000-2001 TP A method comparison for 2000-2001 TP data is a good example.data is a good example.– Data collected for streams and reservoirs with Data collected for streams and reservoirs with

side-by-side analysis.side-by-side analysis.– Purpose was to determine method differences Purpose was to determine method differences

and establish the relationship to apply a and establish the relationship to apply a correction factor for trend analysis.correction factor for trend analysis.

– Plots are provided for examples.Plots are provided for examples.

EOH TP comparisonEOH TP comparison

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Delaware comparisonDelaware comparison

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Catskill comparisonCatskill comparison

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SummarySummary

Checked the requirements of the MUR and developed most Checked the requirements of the MUR and developed most practical field methodspractical field methods

Determined sample size estimates were for all analytes and Determined sample size estimates were for all analytes and sample typessample types– Used existing data to guide decisions for this studyUsed existing data to guide decisions for this study– The number of samples needed was based on the variability The number of samples needed was based on the variability

found in the existing datafound in the existing data Although statistically significant differences were found, the Although statistically significant differences were found, the

median differences suggest that there was little practical median differences suggest that there was little practical difference between the filtered and unfiltered cations.difference between the filtered and unfiltered cations.

Sample size estimates alone may not be enough to Sample size estimates alone may not be enough to determine a relation/correction factordetermine a relation/correction factor

Complete statistical analysis will be performed when project Complete statistical analysis will be performed when project is completed.is completed.