Western Environmental
Testing Laboratory
Microbiology Analyses at WETLAB

Natural resources are important for the livelihood and survival of populations.  One of the most important resources is water, and to be even more specific clean water.  The distribution of water serves many purposes, from aquatic ecosystems, domestic use to commercial and industrial use.  Clean and safe drinking water can be monitored through microbiological testing.  At WETLAB – Western Environmental Testing Laboratory we are proud to offer four certified microbiology analyses and two non-compliance tests.  We are certified in Nevada and California to analyze Presence/Absence (P/A), Quanti-tray, Fecal Coliform, and Heterotrophic Plate Count (HPC).  The two non-compliance tests we offer are tests to determine Iron Related Bacteria and Sulfate Reducing Bacteria.  WETLAB is continuously evolving each department and strives to offer quality data for clients and we encourage method development by researching new tests in order to meet our client needs.

This post is provided to help clients better understand the microbiology analyses at WETLAB.  Each test will be described in detail with regards to what we are testing for, what type of sample matrices can be analyzed for certain tests, brief description of the analyses and the hold times for each test (please note there are two different hold times for Quanti-tray).  The definition that we follow at WETLAB for sample hold time is the time from sample collection to when analysis MUST begin.

 

For more information on microbiology analysis, please refer to Standard Methods, Part 9000, Methods 9222 and 9223.

 

Bacteria Sample Bottle, Volume and Sample Integrity

  • Plastic, sterile bottle
  • Sample bottle contains sodium thiosulfate.
  • Fill to 100 mL line.
  • Chill to 2-6o C.
  • Cleanliness is required!

 

SM 9223 B

Presence/Absence (P/A)

Laboratory Hold time (HT)

  • P/A  =  30 Hour HT

Sample Matrix

  • This test is recommended for the analysis of potable drinking water and fresh source waters

 

Biology Background

  • The scope of this test is to analyze for the presence or absence of Total Coliform bacteria and Escherichia Coli. Total Coliform bacteria are abundant in the environment and are easily identified in the laboratory.  While these bacteria may not be pathogenic they are used as “indicator bacteria,” for the sanitation of drinking water.  If Total Coliform bacteria are present, there is a chance that E.Coli could also be present.  Some types of E.Coli can be found in the guts of living organisms as beneficial co-factors in the daily health of that individual.  Because E.Coli is found in the gut, the purpose of testing for it is to determine the possibility of fecal contamination, which is used as an indicator for the sanitation of a water source.

Laboratory Analysis

  • Tests for Total Coliform and E. coli only.
  • Strictly a qualitative result is obtained.
  • Used almost exclusively for drinking water.
  • 24 hour incubation.
  • Incubation temperature, 35.0 + 0.5 oC
  • Analysis performed in sample bottle.
  • Commercially available chromogenic substrate (ONPG)-known as “Colilert” is used.
  • Colilert is used to detect the enzyme b-D-galactosidase, which is produced by total coliform.
  • Total coliform detection produces a yellow color.
  • Colilert is used to detect the enzyme b-glucuronidase, which is produced by E. coli.
  • E. coli detection produces a fluorescent product when viewed under long-wavelength UV light.

 


SM 9223 B

Quanti-tray (MPN)

 

Laboratory Hold time (HT)

  • Quanti-tray =  30 Hour HT for Drinking water/Source water
  • Quanti-tray =  6 Hour HT for Wastewater samples

Sample Matrix

  • This test is recommended for the analysis of potable drinking water, fresh source water or wastewaters

 

Biology Background

  • The scope of this test is to analyze for a “most probable number” index of the number of Total Coliform bacteria and Escherichia Coli, present in the sample.. Total Coliform bacteria are abundant in the environment and are easily identified in the laboratory.  While these bacteria may not be pathogenic they are used as “indicator bacteria,” for the sanitation of drinking water.  If Total Coliform bacteria are present, there is a chance that E.Coli could also be present.  Some types of E.Coli can be found in the guts of living organisms as beneficial co-factors in the daily health of that individual.  Because E.Coli is found in the gut, the purpose of testing for it is to determine the possibility of fecal contamination, which is used as an indicator for the sanitation of the water source.

Laboratory Analysis

  • Tests for Total Coliform and E. coli only.
  • Quantitative result is obtained.
  • Most commonly used for source water.
  • 24 hour incubation.
  • Incubation temperature, 35.0 + 0.5 oC
  • Uses Colilert just like presence/absence.
  • Sample poured into analysis tray, then incubated.
  • Count yellow/fluorescent wells in tray, this produces MPN-Most Probable Number result.

SM 9222 D

Fecal Coliform

Laboratory Hold time (HT)

  • Fecal Coliform  =  8 Hour HT

Sample Matrix

  • This test is recommended for the analysis source water, wastewaters and sludge’s.

 

Biology Background

  • The scope of this test is to analyze a direct count of colony forming units of fecal coliform.  Fecal coliform can originate in feces (e.g. E.Coli) or non-fecal origin, such as plant materials and paper mill effluents examples of bacteria are Enterobacter, Klebsiella, Citrobacter.  The assay is intended to detect E. Coli as an indicator organism for fecal contamination.

 

Laboratory Analysis

  • Tests for fecal contamination in water.
  • Quantitative result is obtained.
  • Most commonly used for waste water and surface water.
  • 24 hour incubation in water bath.
  • Incubation temperature, 44.5. + 0.2 oC
    • Sample is filtered (0.45 mm), microorganisms collect on filter and grow due to media used in petri dish.
    • Count blue colonies.

SM 9215 B / SimPlate

HETEROTROPHIC PLATE COUNT (HPC)

Laboratory Hold time (HT)

  • HPC  =  8 Hour HT

Sample Matrix

  • This test is recommended for the analysis of potable drinking water, fresh source water or wastewaters.

Biology Background

  • Heterotrophic bacteria, must consume carbon sources for energy and growth.  They are found prevalent in the environment as decomposing bacteria as well as being normal flora of the human body.  Current research is investigating the use of Heterotrophic bacteria testing for similar purposes as P/A and Fecal Coliform, to evaluate the composition of the water, using Heterotrophic bacteria as the “indicator” organism for possible contamination in water.

 

 

 

Laboratory Analysis

  • Tests for Heterotrophic bacteria
  • Quantitative result is obtained.
  • Most commonly used for drinking water.
  • 48 hour incubation.
  • Incubation temperature, 35.0 + 0.5 oC
  • Uses IDEXX’s Multiple Enzyme Technology media.
  • Sample poured into analysis tray, then incubated.
  • Count blue fluorescence, this produces MPN-Most Probable Number result.


SM 9240 B

Iron Related Bacteria (IRB)

 

SM 9240 C

Sulfate Reducing Bacteria (SRB)

Laboratory Hold time (HT)

  • IRB/SRB  =  WETLAB would prefer to use a hold time of 30 Hours

Sample Matrix

  • This test is recommended for the analysis of treated water, distribution systems and water used in for industrial use, such as cooling and boiler waters.

 

Biology Background

  • The scope of these tests are very similar, hence the reason they have been grouped together.  The metabolic processes of Iron Bacteria and Sulfur Bacteria chemically change the constituents they are associated with.  The metabolic wastes can be bothersome because they can form slimes that clog pipelines or affect the aesthetic properties of water.

Laboratory Analysis

  • Tests for either Iron Related Bacteria or Sulfate Reducing Bacteria
  • Strictly a qualitative result is obtained.
  • Most commonly used for water used for industrial and distribution systems.
  • 8 Day incubation.
  • Incubation temperature, 20-25oC
  • Uses BARTTM test kit for IRB or SRB analysis
  • Sample poured into analysis tray, then incubated.
  • Visually inspect for reactions of presence/absence.

Posted by Ginger Peppard, Business Development Manager

I recently attended a great workshop hosted by Placer County and the Town of Truckee entitled “Stormwater Quality Workshop for the Truckee Area Emphasizing Regulations, BMP’s and Low Impact Development.” The workshop was designed to provide contractors, developers, planners, engineers and inspectors with information needed in order to be in compliance with current storm water and non-storm water discharge requirements. It also addressed current regulations, Best Management Practices (BMPs) for construction sites and an overview of Low Impact Development (LID). For more information about the workshop (or to see when they are going to schedule it again!) or about Placer County’s Stormwater Quality Program, email: stormwater@placer.ca.gov.

Why is stormwater monitoring and quality important?

Stormwater runoff occurs when rain or snowmelt flows over impervious surfaces (such as roads, driveways, buildings, sidewalks and parking lots). These impervious surfaces prevent the water from soaking directly into the ground. Stormwater runoff is a problem because, while the water is traveling over these impervious surfaces, searching for an area to infiltrate, it picks up speed, as well as debris, chemicals, dirt and other pollutants. Because stormwater is not treated (or minimally treated in some areas), those large concentrations of pollutants are then deposited directly into the storm drains, or in many cases, directly into streams, rivers, lakes or wetlands.

These harmful contaminants then come in direct contact with fish and wildlife and pollute the water that many of us depend on for recreation activities and for drinking water. Some of the common pollutants found in stormwater are: motor oil, grease, automotive fluids, pesticides, fertilizers, pet waste, paint, solvents, insecticides and sediment and other large debris such as plastic bags, cigarette butts and bottles and cans. Bacteria and other pathogens are also common contaminants and can create serious health hazards. All of these pollutants have serious hazards, either to humans or to the fish and wildlife that inhabit our local streams, lakes and wetlands.

Here are some things you can do to help prevent stormwater runoff pollution:

  • Prevent soil erosion by vegetating bare spots in and around your property. If you have livestock, take all possible steps to prevent overgrazing.
  • Pick up after your pet and dispose of waste in a proper waste receptacle.
  • Cover piles of Pick up after your pet and dispose of waste in a proper waste receptacle.
    loose landscaping materials.
  • Do not disturb vegetation or soil around natural waterways. Stick to defined trails while enjoying the outdoors.
  • Never dump anything down the storm drains or directly into waterways.
  • Dispose of used auto fluids, batteries, solvents, paints and prescription drugs using proper disposal methods. Many of these items have designated drop off or recycling locations.
  • Take your car to the car wash instead of washing it in your driveway.
  • Use fertilizers, herbicides and pesticides sparingly.
  • Don’t over water your lawn.
  • If you have a septic tank, have it professionally inspected every 3 years and pumped regularly.
  • During construction activities, minimize disturbed areas, stabilize slopes and avoid disturbing natural channels. Also minimize the amount of dirt tracked out of the project site.

For more information from Placer County, or additional information brochures for homeowners, construction, Post-Construction and Business/Industrial, visit Placer County’s website at http://www.placer.ca.gov/Departments/Works/StrmWtr.aspx.

Friday, May 29, 2009

Snapshot Day 2009 – May 16, 2009

For those of you are aren’t familiar with Snapshot Day, it is a citizen-based water quality monitoring event of the Lake Tahoe and Truckee River Watersheds. Citizen monitoring teams, led by water resource professionals, and composed of community volunteers and students, field-test streams throughout the watershed for dissolved oxygen (DO), conductivity (EC), pH, and temperature. The also collect discrete water samples that are then taken to a laboratory for the analysis of nutrients, sediments and bacteria. Teams will also conduct visual habitat assessments of the sites. Team leaders will help educate the volunteers and students by sharing interesting watershed facts and provide information about how you can improve and protect your watershed.

This is a great opportunity to learn about your local watershed and get more involved in a great locally driven environmental event. Also, the data collected on this day helps provide a “snapshot” of water quality and stream conditions all throughout the watershed.

For more information about Snapshot day, or if you would like to participate next year (either as a team leader or a volunteer), email Mary Kay Reidl at mriedl@ndep.nv.gov.

This year, our Client Services Representative, Brian Wadsworth, participated in Snapshot day!




You can also contact Brian at brianw@wetlaboratory.com for more information!

As part of a Comprehensive Water Quality Program, Huffman & Carpenter, Inc. (H&C) developed a surface water quality and groundwater quality development program of sampling for the Walker River Paiute Tribe (Tribe). The Tribe implemented a surface water quality monitoring program in 1997 to determine a baseline water quality for the Walker River as it flows through the Reservation. The Tribe is responsible for 323,406 acres in west central Nevada through which the Walker River flows to its terminus in Walker Lake. The long-term goals for the program are to assess water quality within the river and to establish water quality standards for surface water, groundwater, and other significant water bodies within the Reservation boundaries. The primary monitoring program which is currently being implemented is supported by a 106-Grant from the Environmental Protection Agency (EPA) Region IX. The ultimate objective of the Tribe is adoption of Tribal Water Quality Standards, establishment of water codes, and overall management of water resources within Walker River Paiute Reservation.

H&C has utilized Western Environmental Testing Laboratory since 2003 on the Walker River Paiute Tribe project. Specifically, WETLAB has provided the Walker River Paiute Tribe with high quality analytical results for surface water, soil and groundwater testing.

Huffman & Carpenter is located in Reno, NV. They are a group of professional wetland scientists, environmental scientists, biologists, engineers and economists that are dedicated to affect, promote and accomplish watershed restoration for human and wildlife habitats. Their services include, but are not limited to: Erosion Control, Stormwater Pollution Prevention Plans, Water Quality and Water Treatment, GIS and GPS Mapping and Watershed and Hydrologic Modeling. For more information about the Walker River Paiute Tribe project or about Huffman & Carpenter visit their website here.