Western Environmental
Testing Laboratory
Sample Integrity: Sample Collection

Sample Collection is the first, and perhaps the most important step in the analytical process. Poor sampling inhibits the labs ability to produce representative data of a sampling source. Sampling is comprised of 5 main steps:
1. Create a Field Sampling Plan
2. Contact lab to order bottle kit and discuss any scheduling complications
3. Conduct sampling following instructions from Field Sampling Plan and the lab
4. Release Custody of Samples to the lab, or a third party shipper
5. Review Sample Receipt to ensure correct analyses are ordered

What do each of these steps mean? Let’s take a closer look.

1. Field Sampling Plan- This is necessary to succeed in sampling, and generally should include the following:

  • General Facility Info or Sampling Locations
  • Contact Person and Samplers Name
  • Sampling Objectives
  • Facility of Location Information (PWS codes for drinking water)
  • Data Quality objectives
  • Sampling Points
  • Sample Collection Procedure
  • Sample Handling Procedure
  • Equipment Checklist
  • Equipment Preparation and Cleaning Procedures

 

2. Ordering Bottles and Scheduling Sampling- Call us to order your sample containers. The bottles provided will be bagged together into “sets” to keep each site organized. A cooler will also be provided. The lab will generally need the following information:

  • What are you sampling for?
  • How many sites do you intend to sample?
  • When are samples being collected and when will they be delivered to the lab?
  • Are any additional sampling supplies required (COCs, gloves, extra coolers, ice packs, custody seals, Ziploc bags, etc.)?

Depending on the situation, more coordinating and information may be required! For example:

Courier Pick Up or Drop Off– If you need sample containers dropped off at your site or picked up from a courier, it is wise to plan sampling around your labs standard courier routes. You can find WETLAB’s standard courier schedule here.

Sample Shipping– If samples are being shipped to or from a remote location, consider the amount of time samples will be in transit. If you are sending short-hold samples, selecting a “next day delivery” option may be necessary.

Subcontracted Work– Most subcontracting is shipped to southern CA and NV, therefore, factor this extra time in transit when making your sample plan. Furthermore, avoid delivering samples requiring subcontracting on Fridays, as they cannot ship out until the following Monday.

Weekend Work– Weekend work is not ideal, however, it is sometimes unavoidable! It is important, however, to notify your lab as soon as possible about weekend work so that staff can be scheduled to accommodate the request.

 

3. Sampling- Once the game plan is set, it is time to execute your sampling project.

  • Follow the steps outlined in your Sampling Plan and make sure to follow any special instructions provided by your lab.
  • Take note of the weather conditions, high and low temperatures can drastically affect how you pack and transport your samples.
  • Wear PPE! Gloves, glasses, masks, hairnets… they all serve a purpose to keep you safe and/or your samples clean.
  • Make sure to add the proper preservatives to your samples in the field, add custody seals to bottles or coolers if your sample plan requires them, and make sure to use bubble packaging for glass containers.

 

4. Releasing Custody of Samples- An additional responsibility of a sampler is properly documenting sample information and signing for any change of sample custody. The analytical Chain of Custody (or COC) is a required legal document submitted with samples to the laboratory. This document is a requirement for any sample submission to a lab, and serves numerous purposes:

  • Client and Reporting information
  • Turnaround time, compliance needs for reporting, report format, and QC requirements
  • Sample ID, Date/Time, Preservatives, Matrix, Number of Containers, and required tests
  • Miscellaneous comments, including hazard warnings, reporting requests, sample return requests, preservative notes, etc.
  • Relinquishing custody of the samples

 

5. Review Sample Receipt- WETLAB can send you an electronic “ sample receipt” which will list the entered information from your Chain of Custody, the receiving conditions of your samples (including anomalies), and an itemized list of all the analytical testing slated for your samples.
This is the final check before the testing will commence, so it’s important to review as soon as possible and contact the lab with any questions or concerns.

Contact WETLAB at (775)355-0202 to discuss your sampling requirements and project needs.

What is a holding time, and why do I need to know about it? A “holding time” is the elapsed amount of time from the point of collection to the moment of preparation or analysis. Note that this is not the date/time of receipt at the lab! If samples are analyzed beyond an analytical holding time, the data will be qualified on the analytical report and may not be usable for compliance.

The analytical hold time to a sample is like an expiration date to a carton of milk; past the hold time, analysis technically can still be performed (just as milk may be consumed after it expires), the results, however, in both cases may be unsavory. There are very few allowances for missed hold times and in almost every case, resampling is required.

You should get samples to the lab as quickly as possible, as holding times are different for volume received unpreserved. For example, metals shrink from 6 months to 7 days, nutrients from 28 days to 48 hours, others hold times may even shrink to 24 hours or less! Find out more about preservatives and sample bottles here.

Holding times are easily accessible, as the information is constantly needed (and important!):
From WETLAB’s website here
From the EPA under 40CFR, part 136, Table II
From the NDEP website here
Or, get a hard copy sheet on your next stop into WETLAB

Be aware, hold times can change as methods are updated, so you should contact WETLAB for the most up to date information before you develop your sampling plan.

 

What is a preservative, and why is it important? According to the EPA, methods of preservation are relatively limited and are intended generally to (1) retard biological action, (2) retard hydrolysis of chemical compounds and complexes, (3) reduce volatility of constituents, and (4) reduce absorption effects.

In other words, the purpose of a preservative is to “freeze” the sample chemistry at the point of sampling so that what gets analyzed at the lab is as similar to the source as possible, despite the unavoidable delay between the sampling and analysis.

Some common preservatives include:

  • Sulfuric Acid (H2SO4)
    • Preservative for Nutrients: Total Nitrogen, Ammonia, Phosphorus, TKN, etc.
  • Nitric Acid (HNO3)
    • Preservative for Metals: Arsenic, Sodium, Lead, Copper, Iron, Mercury, etc.
  • Sodium Thiosulfate (Na2S2O3)
    • Preservative for Bacteria: Total Coliform, E. Coli, Fecal
  • Sodium Hydroxide (NaOH)
    • Preservative for Cyanide: Total CN, Free CN, WAD CN, etc.
  • Hydrochloric Acid (HCl) in VOA vials
    • Preservative for Volatile Organics: VOCs and Gasoline
  • Hydrochloric Acid (HCl) in Amber Glass
    • Preservative for Organics: Oil & Grease, Diesel, Oil, etc.

 

However, the most important, but often overlooked, preservative is ice. Keeping a sample cold (between 2-6C) is a requirement for nearly every analytical test we perform EXCEPT for metals analysis. It is generally preferable to use wet ice instead of ice packs when possible.

Sample containers, just like preservatives, are designed to inhibit the natural chemical changes which will occur in a sample as time passes. In addition to that, sample containers also serve a few other purposes:

  • To ensure proper volume is provided to a lab (all tests have a minimum required volume)
  • To ensure the lab has enough volume to perform the proper quality control
  • Some containers limit a samples exposure to UV rays
  • Some containers are designed to prevent sample contact with air
  • Some are sterilized and sealed to prevent bacteria contamination
  • Some containers are designed to limit sample absorption (plastic vs. glass)
  • Some are specifically designed to be loaded directly into an instrument (or even an autosampler for composite samples)

 

But how do I know which sample bottle and preservative to use? Simple, you ask the lab! By contacting WETLAB before you begin your sampling process, you will help ensure that you use the correct bottle and preservative. Our staff can also help you review your permit making sure the correct samples are taken at the correct time of the year (DPBs, LCR, SOCs), and making sure the correct methods are used for your sample matrix (drinking water, waste water, haz waste). We can even help with sampling requirements making sure your samples are collected as intended by your permit (LCR first draw, grab vs. composite), saving you valuable time that can be lost from unintended mistakes.

Be aware, preservatives and hold times are dictated by the analytical method and enforced by state/federal agencies and the laboratory. Cyanide species, Volatile Organics, Dissolved Oxygen, Bacteria, SOCs, DBPs, and many other tests absolutely require correct bottles and preservatives to analyze for compliance.

Contact WETLAB at (775)355-0202 to discuss your sampling needs. Our seasoned staff can help you determine which samples you need, how they need to be collected, and provide you with all the right bottles and preservatives to make sure your procedures remain in compliance.

In our blog posts Lessons From the Lab we answer frequently asked questions from clients.  Find all installments of Lessons From the Lab here

Cyanide sampling requirements have become stricter over the years. The Nevada Division of Environmental Protection (NDEP) issued guidance in October of 2015 that cyanide analysis must be collected correctly in the field so as not to have samples rejected by the analytical laboratory, or by the state due to incorrect sampling procedures.

NDEP stated, “If you are analyzing Cyanide samples for compliance with a Nevada program, (SDWA, CWA, RCRA, Mining) samples must be collected as described below (ASTM D-7365-09).  Data obtained from samples not collected as described in ASTM D-7365-09 will be rejected.”

“ASTM D-7365-09 8.2.1 states that sample containers shall be made of materials that will not contaminate the sample, cleaned thoroughly to remove all extraneous surface contamination prior to use.  Chemically resistant glass containers as well as rigid plastic containers made of high density polyethylene (HDPE) are suitable.  Samples should be collected and stored in amber gas tight vials or narrow mouth bottles to minimize exposure to ultraviolet radiation and to minimize headspace in the sample containers (for example, amber open top VOA vials, amber Boston round bottles, or amber narrow-mouth HDPE bottles).”

“All certified Laboratories must reject samples not collected in suitable containers.”

What does this mean? All samples, regardless of matrix (drinking water, wastewater, ground water, surface water, aqueous, soil, sludge, etc.), must be collected in an amber narrow mouth container to minimize UV radiation exposure and to minimize headspace in sample containers.  Samples not collected in the correct containers must be rejected by the laboratory and the sample should be collected in the correct containers, as described above. Furthermore, as dictated by the method cited by NDEP, chemical preservation is also required for aqueous samples.  Aqueous samples must be preserved with sodium hydroxide (NaOH) to pH >10 at the time of collection, and then chilled on ice.

At WETLAB, we provide the appropriate bottles and preservative (NaOH) needed for your cyanide analysis, and are happy to answer any questions you may have regarding cyanide sampling containers.

Please call us at any at 775-355-0202 to request sample containers.

WETLAB is pleased to announce a new certification.  We have expanded our testing abilities, and are now certified in Nevada to analyze Total Organic Carbon (TOC) by SM5310C.  Total Organic Carbon (TOC) is a measurement of organic or carbon-based contaminants in water that come from a variety of sources.  SM 5310C uses a UV-Persulfate TOC analyzer to measure total organic carbon in drinking water, surface water, ground water, and waste water.

At WETLAB, we are constantly trying new ideas, methods, and analyses to better serve our clients.  Contact us at (775) 355-0202 to find out how our new, in-house TOC analysis can help you get the environmental testing results you need.

WETLAB has been participating in Snapshot Day for over a decade!  Snapshot Day is coordinated by the Bureau of Water Quality Planning within the Nevada Division of Environmental Protection (NDEP).  Snapshot Day occurs annually and is a two-day event where the Urban Truckee River portion of the watershed is sampled from the outlet at Lake Tahoe to its end at Pyramid Lake.  That’s more than 105 miles!  Snapshot Day is an event that involves the community and education outreach; volunteers from local businesses and organizations spend their time teaching students throughout the Tahoe and Truckee Basin about conservation, ecology, hydrology, environmental stewardship, and water quality.  In addition, site facilitators conduct a stream walk for habitat assessment and sample collection for field and laboratory testing.  In conjunction with NDEP, these small groups help create a larger picture of the health of the Basin and watershed.  This provides longitudinal data that helps identify possible sources of pollution or other contamination and information for community planning and development.

On Friday, May 18th 2018, WETLAB volunteered for the 18th Annual Snapshot Day.  Our sampling site was part of the Lower Truckee River at Whites Creek on the campus of Mountain View Montessori School.  As facilitators, we had the opportunity to teach 4th & 5th grade students about the importance of a healthy watershed, water quality, field testing methods, the water cycle, and environmental sustainability.  We were excited to provide a hands-on learning experience to stimulate interest and stewardship while learning about pollution, invasive species, the water cycle, and procedures for field testing.  We also emphasized the importance of observation and protection of our unique water resources.

Team WETLAB at White's Creek for Snapshot Day 2018.

Team WETLAB at White’s Creek for Snapshot Day 2018.

In our blog posts Lessons From the Lab we answer frequently asked questions from clients.  Find all installments of Lessons From the Lab here

It is important to know the differences for the client and the lab when the topic of compliance vs. non-compliance comes up. The simplest way to view it from a client perspective is that compliance data would be data that any type of regulator would review. It could be a state regulator or sometimes the EPA itself. Many times, compliance data will be sent directly to the state by WETLAB. In a more complex twist we have seen this past month NON-compliance data be subpoenaed to US District Court. This proves that even if the client indicates non-compliance we should be following all the normal rules as we do for compliance samples. All samples should certainly be collected properly as far as container and preservative types go and correct sample volume should be provided. From a lab perspective whether or not a sample is for compliance doesn’t really get discussed too often. It is simpler, and safer, to treat all samples the same. In rare occurrences, with lab and QA management oversight, protocols may be altered for non-compliance samples.

Snapshot Day has become an annual WETLAB tradition.  We love getting out into nature and helping to inspire the next generation of scientists!  Jen Delany, one of our regular leaders for Snapshot Day, wrote the overview below. 

WETLAB Snapshot Day leaders Jen, Cory, and Vanessa.

WETLAB Snapshot Day leaders Jen, Cory, and Vanessa

On Friday May 12th 2017, WETLAB volunteered for Snapshot Day, which is coordinated by the Bureau of Water Quality Planning (NDEP). Snapshot Day occurs annually and is a one-day event where the Urban Truckee River portion of the watershed is sampled from the outlet at Lake Tahoe to its end at Pyramid Lake. That’s a total of 105 miles! Snapshot Day is an event that includes the community and education outreach; different businesses and organizations volunteer their time to teach students throughout the Washoe basin about conservation, environmental stewardship, and water quality.   In conjunction with NDEP, these small groups help create a larger picture to determine the health of our watershed over time and identify possible sources of pollution or other contamination. In addition, site facilitators conduct a stream walk for habitat assessment and sample collection for field and laboratory testing.

WETLAB’s sampling site along the Truckee River this year was Whites Creek on the Mountain View Montessori School campus. As facilitators, we had the opportunity to teach the 4th & 5th grade students about the importance of a healthy watershed, water quality, field testing methods, the water cycle and environmental sustainability. We had a unique opportunity this year to educate the students about the Atmospheric River and how the allocation of water is managed within our state. Students were engaged and incredibly helpful.

WETLAB staff enjoyed providing a hands-on learning experience to stimulate interest and stewardship. We hope to continue volunteering for this event year after year!

WETLAB is a certified lab for drinking water testing in Nevada, with reciprocity for testing in California, Wyoming, and Idaho.  This means that when you send drinking water samples to WETLAB, we guarantee thorough, high-quality data that complies with regulatory standards.  We ensure that your sample is analyzed with up-to-date methods, performed with the precision and attention to detail that you require.  We analyze drinking water for regulated public water systems of all sizes and for private domestic wells.

Private domestic well owners face a unique set of circumstances not often realized by many people who utilize a community water system.  Well owners are responsible for ensuring their own water quality, which means regular water testing.  Your water can contain microscopic particulates and micro-organisms that you would be unable to detect with your naked eye.  The Environmental Protection Agency recommends testing your well regularly for several contaminants, including total coliform, pH, corrosion, nitrates, and metals.  If you experience any changes in water quality, such as rapid corrosion of pipes, undesirable tastes or smells, or increased scaly build-up, you may be interested in testing your water quality.

If you are interested in testing your private domestic well, reference this helpful guide from the UNR Cooperative Extension.  This guide will help you determine what drinking water parameters you may be interested in testing for, and what the critical limits for some contaminants are.  After you test your water, you can use this tool to help interpret your results.  Our friendly staff at WETLAB will be happy to assist you with any other questions you might have.

WETLAB provides a uniquely client-oriented lab experience that will ensure you obtain the quality lab results you seek.  Contact WETLAB at (775) 355-0202 to determine how we can help you.

This is the final installment of our ongoing series Life of a Sample, which explores what happens behind the scenes at WETLAB.  If you missed parts one through five, check them out here!

Our sample has now been received, prepped, distilled/ digested, analyzed, and entered.  The final, and terminal step, is reporting.  At this point, samples will have been validated, which means that QA/QC parameters have been checked to ensure they are within acceptable ranges.  These parameters include checking total versus dissolved solids, Maximum Contaminant Levels (MCLs) for drinking water, cation versus anion balances, and several others.  If any of these validation measures are outside of acceptable or expected limits, QA staff will determine if the sample needs to be re-analyzed.  If the sample passes the validation check, the data is ready to be reported to the client and regulating agency. Our client services staff ensures that clients are provided with a complete and accurate report of all results, and they understand what they have been provided with.  If the sample is being analyzed for compliance, such as drinking water for a public water system, the results are also provided to the regulating agency.  After reporting is finished, our sample’s life cycle is complete!