Field Audit & System BlankFAQs

NADP Webinar Series

August 21, 2013

Frequently Asked Questions

May I process the Field Audit or System Blank sample? I know that it did not rain or snow during the sampling period, but...

1) the collector opened at least once during that time.YES. Provided no precipitation occurred during the sampling period, collector openings are acceptable.

2) dew or moisture condensing on the sensor caused the collector to open.NO, generally. The sensors (grid and optical) are heated. Moisture should not form on the sensor. Verify that the sensor is working properly. If yes, the sensor may have been triggered by mist or light rain/snow.

3) fog caused the collector to open.NO, generally. Fog can result from either a low lying cloud, or from moisture evaporating from the Earth’s surface. Explain lid openings on MOF or FORF.

4) there is insect and/or plant material in the bucket, funnel, or bottle.YES. This is the goal of the Field Audit and System Blank programs.

5) the collector lost power (while closed) and did not operate for a portion of the sampling period.No.

6) there was light precipitation during the sampling period, but the collector did not open.NO. For consistency within the Field Audit and System Blank programs, the sampling period must be dry.

7) the Field Audit or System Blank sample has an expiration date that has passed.YES. Provided the sample is for the current year, it may still be used. If the sample is from a previous year, dispose of the sample, and submit the accompanying postcard.

8) the Field Audit or System Blank sample has an expiration date from a previous year.NO. Dispose of the sample, and submit the accompanying postcard.

9) the Field Audit or System Blank sample bottle broke or leaked during shipment to my site.NO. Dispose of any remaining sample, and submit the accompanying postcard – if it is in good condition. If the postcard is damaged, notify Greg Wetherbee at wetherbe@usgs.gov. Note, the Field Audit and System Blank samples are not hazardous.

10) I poured the entire sample into the NTN bucket (or MDN bottle), what should I do?Dispose of the sample, and submit the accompanying postcard. Note, the Field Audit and System Blank samples are not hazardous.

11) I poured the proper amount into the NTN bucket (or MDN bottle), but then discarded the remaining portion. What should I do?Dispose of the sample, and submit the accompanying postcard with a note explaining what happened. Note, the Field Audit and System Blank samples are not hazardous.

12) I (accidentally?) poured the entire Field Audit/System Blank sample into a valid NTN (or MDN) sample. What should I do?

Dispose of the sample, and contact the Site Liaison and Greg Wetherbee (wetherbe@usgs.gov). Note, the Field Audit and System Blank samples are not hazardous.

Common Mistakes

1. DO NOT send a dry sample envelope (NTN) when submitting a Field Audit sample. The 2 bottles for the Field-Audit sample and 2 accompanying FORFs are all that is needed.

2. Two (2) bottles should be submitted for all Field-Audit and System-Blank samples: (1) the sample that rinsed the bucket (NTN) or sample train (MDN), and (2) the portion of sample still remaining in the original bottle shipped to you by USGS.

Results

“So, what does USGS do with these data anyway?”

Results

Time Period

System Blanks

Processed(N)

Contamination Concentrations Below MRL with 90% Confidence

(Percent)

90% UCL on 90th PercentileSystem-Blank -minus- Control

Sample Hg Mass

Differences (Network

Maximum Contamination Level, ng)

2004 44 92 0.010

2004-05 88 88 0.009

2004-06 95 80 0.005

2005-07 104 60 0.136

2006-08 128 45 0.233

2007-09 144 35 0.325

2008-10 147 30 0.325

2009-11 150 20 0.285

2010-12 164 15 0.260

Online Training Videos

http://pubs.er.usgs.gov/publication/ofr20061010

Online Training Videos

http://bqs.usgs.gov/PCQA/System_Blank/systemBlankTrainingVideo.php

A recording of this webinar will be made available on the NADP website:

http://nadp.isws.illinois.edu

Contacts

• Greg Wetherbee, USGS Precipitation Chemistry Quality Assurance Project Chief, 303-236-1837, wetherbe@usgs.gov

• RoseAnn Martin, USGS Precipitation Chemistry Quality Assurance Project, Physical Scientist, 303-236-1874, ramartin@usgs.gov

• Web site: http://bqs.usgs.gov/

Special Thanks

• RoseAnn Martin (USGS) – Field Audit and System Blank implementation, webinar props

• Mark Rhodes (NADP Program Office)• Brian Kerschner, Jeff Pribble (Central Analytical

Laboratory)• Jason Karlstrom (Frontier Global Sciences,

HAL)

Additional Credits• Catch Efficiency Technician: Phil DeBuckets• Optical Sensor Engineer: Dewey C. Rain• Contamination Technician: Harry Messinwater• Quality Assurance Assistant: Howie Duin• Belfort Chart Reader: Violet Fingers• Meteorologist: Gail Forcewinds • Customer Service Rep.: Ida Noh• SOP Editor: Reed Pages• Accountant: Bill U. Later• Webmaster: Dorothy “Dot” Kahm