Checklist of Common Critical Data Issues:

Transcription

1 Checklist of Common Critical Data Issues: EPA s Hazardous Air Pollutants for Coal- and Oil-fired Electric Utility Steam Generating Units Information Collection Request This document contains a checklist of common "critical" errors in sampling/analytical procedures and electronic data entry observed by EPRI. Critical errors are those that EPRI estimates will have a significant negative impact on the quality or usability of the data. For power plants participating in the EPRI data review, respondents should review this checklist before sending files. This will allow EPRI to put resources to the best use and improve the overall quality of the ICR data. The checklist may be updated as new findings are noted. Checklist of s: ICR Electronic Reporting ERT: will not calculate emissions in Each file should be checked using the EPA s ERT application. This behavior is often due to one of lb/mmbtu or will not print a Test Report the following: Methods, locations, runs or parameters without an associated emissions value SCC code not entered File size too large - EPA has requested that test report and other supporting information not be attached to the ERT but uploaded separately. For Method 10 and 25A data, it is necessary to add ppm units to the method setup in order for the ERT to properly calculate lb/mmbtu. On the ERT- Main Menu, select Locations/Methods under the Setup/Test Plan module. In Section 7b, click Add Emissions/Concentrations. In the pull-down menu at the top of the dialog box, select the method for which you d like to add an emission concentration. Then, click the << button. Select ppm from the menu on the left and click >. Click the Save Selected Items button to close out of the window and save your changes. If these items are fixed and the Test Report still will not print, contact EPA for assistance. ERT: incorrect detection limit format entered The correct format is a numerical value representing the detection limit. No data quality flags or in Emissions field other text characters should be in this field. For each emission value, a detection flag should be entered in the Flag field (see next item). ERT: contents of Flag field differ from EPA The Flag field should contain one of the following for every emission value: ADL, BDL, or DLL. requirements Check that all detection flags are assigned correctly. DLL indicates a multi-fraction method in which one fraction is above the detection limit and the other fraction is below detection limit. No other text should go in the Flag field! The only exception is for Method 23 dioxin/furan/pcb values that the lab has identified as EMPC. EPA has provided guidance to leave the Flag field empty, and enter EMPC in the Comment field.

2 ERT: incorrect detection limit entries for In the Comments field, list each individual fraction in brackets using the format [##] (if above multi-fraction methods (e.g., metals by detection limit) or [<##] (if below detection limit). Sum the detected values and detection limits to Method 29) obtain the value entered into the Emissions field. ERT: errors in emissions calculations Check that lb/mmbtu emission rates reported by the ERT are correct (i.e., that the calculation of emission rate from mass and gas volume corresponds to the lb/mmbtu value calculated in the stack test report). Various mistakes have been noted in the lb/mmbtu calculations, including the use of the wrong F-factor (i.e., wrong O 2 basis) and incorrect entry of process paramete rs. OTM: older versions of spreadsheet do not If possible, use the latest version of the Emissions (OTM) spreadsheet posted on EPA s ICR support additional test runs website. Do not insert columns, as this will cause problems for EPA s data extraction procedures. OTM: incorrect detection limit format In the OTM spreadsheet, values below detection limits should be entered in the Calculated Emission Rate field in brackets using the format [<##]. OTM: contents of Data Flag field differ from The Data Flag field (found in the May 18, 2010 and later versions of the EPA spreadsheet) should EPA requirements contain one of the following for every emission value: ADL, BDL, or DLL. In earlier versions, there is no Data Flag column and this information will have to be entered into the Other Supporting Information column. Check that all detection flags are assigned correctly. DLL indicates a multi- limit and the other fraction is below fraction method in which one fraction is above the detection detection limit. No other text should go in the Data Flag field! Results for the individual fractions should be entered in the Other Supporting Information field. ERT: EPA s Electronic Reporting Tool Table Version: August 17, 2010 Other important reporting issues: One issue that we have noted in most ICR data sets is the omission of the detection limit methodology requested by EPA for this ICR. Because laboratories are not consistent in how they derive detection or reporting limits, and EPA may use the reported nondetect values to determine regulatory limits, it is very important for the appropriate use of the ICR data that this information be provided. EPA has not provided guidance on the level of detail required. EPRI recommends including a concise statement of the basis of the values used to represent nondetects in the Comments field of the Electronic Reporting Tool and in the Other Supporting Information column of the OTM spreadsheet. A more detailed explanation of the methodology can be included in the Test Report.

3 Checklist of s: Method 26 or 26A Acid Gases (HCl and HF) Sodium hydroxide impinger used to If HCl and HF were measured using sodium hydroxide (NaOH)impingers, a note should be added to the measure acid gases ERT Comment field that this methodology was used. EPA initially recommended measuring acid gases and cyanide (HCN) in a combined Method 26/CTM-033 train using only NaOH impingers. This methodology generally resulted in HCl and HF detection limits about 100 times higher than the typical detection limit for Method 26, which uses sulfuric acid impingers for HCl and HF. EPA now recommends using a sulfuric acid impinger to measure acid gases. Quality control samples fail method Verify for all HCl and HF: laboratory control sample (LCS) spike recoveries between %, matrix spike/matrix spike duplicate recoveries between %, duplicate analyses of samples should agree within 5%. Results outside these ranges indicate uncertainty in the results due to inaccuracy or impreciseness and this should be noted in the ERT comments field. Incorrect probe/filter temperature for The Method 26 probe and filter should be heated above 248 F. Temperatures significantly lower than Method F can potentially lead to moisture condensation and a low bias in the sample results. Method 26 requires temperature to be above 248 F, not within the 248±25 F range specified by Method 5. Several sites have incorrectly performed Method 26 by adhering to the latter criterion. Chec klist of s: CTM-033 Hydrogen Cyanide (HCN) Sodium hydroxide impinger ph <12 Quality control (QC) samples fail method Verify that the final ph of the sodium hydroxide (NaOH) impinger liquid as received by the laboratory was >12. Low ph can result in low capture efficiency (i.e., a low bias in measured value). Note ph<12 in the Other Test Methods (OTM) Other Supporting Information column Verify: laboratory control sample (LCS) spike recoveries between %; matrix spike/matrix spike duplicate recovery between %; duplicate analyses of samples relative percent difference (RPD) <25%. Failure to meet these indicates greater uncertainty and potential bias in the results. QC values not meeting should be noted in the OTM Other Supporting Information column.

4 Checklist of s: Method 29/5 Metals and Particulate Matter (PM) Blank contamination for metals Calculate the ratio of the sample mass to the blank mass for each metal. A ratio of less than approximately five indicates that either the blank contained significant contamination or the sample mass was very low. In either case, a note should be included in the ERT Comments field indicating that the reported mass may not be accurate due to the sample value being close to the blank value. Front half and back half metals results not EPA is requiring both components of the analysis (filter and impinger catch) to be reported in the ERT reported Comments field. For example: 5.8, [<0.5]. If the lab did not report front/back half results, note this in the Comments field. Incorrect summation of front/back half Sum fractions using the detection limit to represent masses below detection limit. Do not use zero to results represent nondetects. Blank correction performed incorrectly EPA states that blank correction should be performed per Method 29. When blank correction results in a value below the limit of detection, the detection limit should be used as the concentration value in summing the front half and back half fractions. Elevated manganese Highly elevated Mn has been observed when a permanganate impinger was included i n the sampling train. Back half sample Mn >50% of the front half Mn indicates likely contamination. In this case, a note regarding sample contamination should be made in the Comments field of the ERT. Quality control samples fail method Verify for all metals: laboratory control sample (LCS) spike recoveries between %, matrix spike/matrix spike duplicate recoveries between %. Recoveries outside of these ranges indicate a potential bias and this should be noted in the ERT Comments field. Method 5 PM results not reported Filterable PM results from the Method 5 filter associated with the Method 29 trains should be reported in the ERT. EPA does not require the PM results to be reported if a Method 5/OTM-28 train was run simultaneously with the Method 29 train. Incorrect filter temperature for Method The Method 5 filter associated with the Method 29 train should be heated at 248±25 F, not 320±25 F. 5/29 filter Several sites with wet stacks have mistakenly operated the filter at 320 F; for wet stacks; it is the Method 5 filter associated with OTM-28 that is held at 320 F. ERT: EPA s Electronic Reporting Tool

5 Checklist of s: Method 30B Mercury (Hg) Emissions calculated incorrectly Quality control (QC) samples fail method Incorrect sample mass entry for values below detection limit The Hg concentration reported for each run should be the average of the paired tubes (i.e., the average of the unspiked tube and the corrected value from the spiked tube). The Hg concentration for the tube should include the mass of Hg collected on the first bed and the second bed. For a Method 30B run to be valid, it must pass all three of the following QC : (1) Average of the first bed spike recovery for the three runs must be %. (2) Breakthrough to the second bed must be <10% (or <20% if concentration is <1 µg/m 3 ). (3) The paired trap agreement must be within 10% relative difference (RD), or 20% RD if concentration measured is < 1 µg/m 3. If a run is invalid, note this in the Other Supporting Information column of the Other Test Methods (OTM) spreadsheet. Verify that the sample mass falls within the calibration curve. Method 30B indicates that the lowest point of the calibration curve must be at least 5 times the Method Detection Limit and that all analyses of field samples must fall within the calibration curve. For very low mass emitters, it may be difficult to collect enough Hg on the first bed to exceed the lowest point on the calibration curve. Likewise, for samples with very low breakthrough to the second bed, the sample mass for the second bed may not exceed the lowest point on the calibration curve. In such cases, follow the specific instructions given in Section 11.3 of Method 30B for when the sample mass falls between the method detection limit (MDL) and the lowest point on the calibration curve.

6 Checklist of s: Method 5 at 320 F/OTM-28 Filterable and Condensable Particulate Matter (CPM) Incorrect filter temperature used Failure to report all PM fractions requested by EPA Blank correction performed incorrectly Blank contamination ERT: EPA s Electronic Reporting Tool EPA required that units with a wet stack perform Method 5 at a temperature of 320±25 F. This method should have been performed in conjunction with OTM-28. Running the method with the normal filter temperature of 248±25 F may produce a high bias in filterable PM and a low bias in CPM. EPA requested that the following four Particulate Matter (PM) results be reported in the ERT: 1. Filterable Particulate (from Method 5 train) 2. Organic Condensable Particulate (organic fraction of OTM-028) 3. Inorganic (Aqueous) Condensable Particulate (inorganic fraction of OTM-028) 4. Total Particulate (sum of the following fractions of the Method 5/OTM-028 train): a. Filterable Particulate b. Organic Condensable PM c. Inorganic Condensable PM OTM-28 requires that blank correction should be limited to g for the sum of the organic and inorganic CPM fractions. If the sum of the blank fractions exceeds g, the most accurate method of blank-correction is to allocate the g in proportion to the relative blank masses of the two fractions. However, this approach is not contained in OTM-28, which only addresses correction of the total CPM. Evaluate the ratio of the sample mass to the blank mass. A ratio of less than approximately five indicates that either the blank contained significant contamination or the sample mass was very low. In either case, a note should be included in the ERT Comments field indicating that the reported mass may not be accurate due to the sample value being close to the blank value.

7 Checklist of s: OTM-27/OTM-28 PM2.5/Condensable Particulate Matter (CPM) Incorrect PM method used EPA required that units with a dry stack perform OTM-27 in conjunction with OTM-28. Failure to report all PM fractions requested EPA requested that the following six Particulate Matter (PM) numbers be reported in the Electronic by EPA Reporting Tool (ERT): 1. Filterable PM2.5 (Filterable PM < 2.5 from OTM-27) 2. Organic Condensable Particulate (organic fraction of OTM-028) 3. Inorganic (Aqueous) Condensable Particulate (inorganic fraction of OTM-028) 4. Total PM2.5 (sum of filterable PM < 2.5, Organic Condensable Particulate, Inorganic Condensable Particulate) 5. Filterable Particulate (sum of PM<2.5 and PM>2.5) 6. Total Particulate (sum of the following fractions of the OTM-027/028 train): a. Filterable PM > 2.5 b. Filterable PM < 2.5 c. Organic Condensable PM d. Inorganic Condensable PM Blank correction performed incorrectly OTM-28 requires that blank correction should be limited to g for the sum of the organic and inorganic CPM fractions. If the sum of the blank fractions exceeds g, the most accurate method of blank-correction is to allocate the g in proportion to the relative blank masses of the two fractions. However, this approach is not contained in OTM-28, which only addresses correction of the total CPM. Blank contamination The ratio of the sample mass to the blank mass should be evaluated. A ratio of less than approximately five indicates that either the blank contained significant contamination or the sample mass was very low. ERT: EPA s Electronic Reporting Tool. In either case, a note should be included in the ERT Comments field indicating that the reported mass may not be accurate due to the sample value being close to the blank value.

8 Checklist of s: Method 23 Dioxins/Furans and PCBs Blank contamination The ratio of the sample mass to the blank mass should be evaluated for each compound. A ratio of less than approximately five indicates that either the blank contained significant contamination or the sample mass was very low. In either case, a note should be included in the ERT Comments field indicating that the reported mass may not be accurate due to the sample value being close to the blank value. Incorrect reporting of non-detect values Do not use zero to represent nondetected congeners. Use the Estimated Detection Limit (EDL) for the specific sample and congener, as reported by the laboratory. Quality control indicators fail method Verify for all dioxin/furan congeners: internal standard/surrogate recoveries between % for tetra through hexa-cdds and -CDFs, and between % for hepta and octa -CDDs and -CDFs. Verify for all PCB congeners: internal standard recoveries and lab control sample (LCS) spike recoveries meet the laboratory s stated acceptance. Recoveries outside these ranges indicate higher uncertainty in the results and the out-of-range QC results should be noted in the ERT Comments field. Other dioxin/furan parameters not reported or reported incorrectly EMPC values not correctly coded ERT: EPA s Electronic Reporting Tool. EPA requires Other dioxin/furan congener groups (e.g., Other hexa-cdd) to be reported in the ERT, but Total dioxin/furan congener groups do not need to be reported. The calculation of the Other category is typically performed by subtracting the individual target congener results from the Total categories normally reported by laboratories. EPA has not provided guidance on how to handle values below detection limits in this computation. Do not report zeros for the Other dioxin/furan congener groups. Some laboratories assign an EMPC (Estimated Maximum Potential Concentration) flag to dioxin/furan results that do not meet all of the Method 23 for positive identification as a target compound. EPA has provided guidance that EMPC values should be indicated as follows: omit any entry into the Flag field of the ERT and enter EMPC in the Comments field. Note that some laboratories may use other symbols to indicate EMPC, but the same guidance would apply.

9 Checklist of s: Method 0010 Semivolatile Organic Compounds (SVOC) Blank contamination Evaluate the ratio of the sample mass to the blank mass for each compound. A ratio of less than approximately five indicates that either the blank contained significant contamination or the sample mass was very low. In either case, note in the ERT Comments field that the reported mass may not be accurate due to the sample value being close to the blank value. Incorrect list of SVOC compounds Refer to EPA FAQ Questions Test-014 and Test-041 for guidance on which SVOC compounds to report. reported Please be aware that the laboratory may have reported compounds that are not Haza rdous Air Pollutants (HAPs). Incorrect summation of fractions for multi- The reported mass should be the sum of the individual fractions of the train. For fractions with results fraction methods below detection limit, the detection limit should be used in the summation and the DLL flag used in the Flag field. In no case should a zero value be used for a fraction.

10 Blank contamination Checklist of s: Method 0031 VOCs Evaluate the ratio of the sample mass to the blank mass for each compound. A ratio of less than approximately five indicates that either the blank contained significant contamination or the sample mass was very low. In either case, a note should be included in the Other Test Methods (OTM) Other Supporting Information column indicating that the reported emissions may not be accurate due to the sample value being close to the blank value. It is very important to review the blank data for detected VOCs and to add a note to the Other Test Methods (OTM) Other Supporting Information field if the results are suspected to be due to contamination. Common laboratory solvents that are frequently seen as contaminants in Method 0031 include methylene chloride, acetone, and toluene. Low level detections are often due to the presence of these solvents in the sample recovery or laboratory areas. In some cases, gross contamination has been noted in ICR samples. Incorrect reporting of VOC compounds Incorrect summation of fractions for multifraction methods Benzene, chloromethane, and bromomethane are commonly detected as artifacts in Method 0031 samples and may not be derived from the emissions source. If these chemicals were detected, the possibility of sample field contamination should be investigated. A positive field blank result is evidence of contamination. However, since many contractors do not uncap the field blank tubes while in the field, a negative result in the field blanks does not rule out cross-contamination from solvents used in the field. Refer to EPA FAQ Questions Test-014 and Test-041 for guidance on which VOC compounds to report. Please be aware that the laboratory may have reported compounds that are not Hazardous Air Pollutants (HAPs). The reported mass should be the sum of the individual fractions of the train. For fractions with results below detection limit, the detection limit should be used in the summation and the DLL flag used in the Flag field. In no case should a zero value be used for a fraction.

11 Incorrect reporting of results Checklist of s: Method 18 Methane (CH 4 ) If Method 18 was performed with the direct interface method, EPA requires the concentrations to be reported as measured in the Emissions field, including negative values. All runs should be flagged as ADL in the Other Test Methods (OTM) spreadsheet Data Flag column. If Method 18 was performed as a bag sample and the results were below detection limit, then the detection limit should be reported in the OTM spreadsheet as [<XX] in the Emissions field, and a BDL flag should be entered in the Data Flag column. Quality control samples fail method If Method 18 was performed with the direct interface method, the system span recovery should be between %. If Method 18 was performed as a bag sample, then the bag recovery should be between %. Results that meet the recovery should still be corrected fo r the recovery. Recoveries outside these ranges indicate a likely bias in the results and should be noted in the OTM Other Supporting Information column. Background ( zero gas ) levels equivalent Evaluate the ratio of the sample concentration to the zero gas concentration for each run. A ratio of less to measured levels than approximately five indicates that either the zero gas or sampling system contained significant contamination or the sample mass was very low. In either case, a note should be included in OTM Other Supporting Information column indicating that the reported mass may not be accurate due to the sample value being close to the zero gas value. Checklist of s: Method 25A Total Hydrocarbons (THC) Incorrect reporting of results Method 25A is a direct interface method. EPA requires the concentrations to be reported as measured, including negative values. All runs should be flagged as ADL in the ERT Flag field. Background ( zero gas ) levels equivalent to measured levels ERT: EPA s Electronic Reporting Tool. Evaluate the ratio of the sample concentration to the zero gas concentration for each run. A ratio of less than approximately five indicates that either the zero gas or sampling system contained significant contamination or the sample mass was very low. In either case, a note should be included in the ERT Comments field indicating that the reported mass may not be accurate due to the sample value being close to the zero gas value.

12 Checklist of s: Method 0011 Formaldehyde Blank contamination Quality control samples fail method Evaluate the ratio of the sample mass to the blank mass. A ratio of less than approximately five indicates that either the blank contained significant contamination or the sample mass was very low. In either case, a note should be included in the Other Test Methods (OTM) Other Supporting Information column indicating that the reported emissions may not be accurate due to the sampl e value being close to the blank value. Verify that lab control sample (LCS) spike recoveries meet the laboratory s stated acceptance. Checklist of s: Method 316 Formaldehyde Blank contamination Quality control samples fail method Evaluate the ratio of the sample mass to the blank mass. A ratio of less than approximately five indicates that either the blank contained significant contamination or the sample mass was ve ry low. In either case, a note should be included in the Other Test Methods (OTM) Other Supporting Information column indicating that the reported emissions may not be accurate due to the sample value being close to the blank value. Verify that lab control sample (LCS) spike recoveries meet the laboratory s stated acceptance.