OC Laboratory

Event Coordinator	Event Vice-Coordinator
Melodi Clark Surveillance Lab Manager Wastewater Chemist City of Columbus	Nora Lough Narragansett Bay Commission Providence, RI

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2026 Laboratory Event Description *UPDATED 2/2/26

2026 Laboratory Judging Sheets: Head Judge; Judge 2; Judge 3; Judge 4 *UPDATED 2/2/26
The judging sheets are provided primarily for event coordinators and judges information only. They are not part of the procedures or the rules of the event. They are for reference only and do not govern; the event descriptions govern. They are updated periodically and are subject to change at any time, without notice. They may not be used in any form of protest or question. There may be actions that are penalties that are not explicitly listed as an example on the penalty sheet.

Laboratory Event Tutorial*NEW 11/2025
Tutorials should be used as an overall suggestion not 100% accurate

Bench Sheet and Calculations	Equipment Purchase	Tables
Chlorine Bench Sheet*UPDATE 1/20/26	Discount Codes for Hach purchases (20% off) US - LABTEST Canada – LABTESTCA	Table Layout Photo is two set ups back to back. WEFTEC setup will be tables in a row – left to right – at an angle. Like an arrowhead.
Phosphate Bench Sheet*UPDATE 1/20/26
Calculations for the PO4 and CL2 solution/concentration
10209 instructions

**These videos are for informational purposes only and may not necessarily be a clean run.

Ask A Question

Questions are accepted up until 9/18/26. Questions can be asked at the pre-competition meeting on Monday, September 28 in New Orleans

Question	Answer	Date
On the material list there is a 50 g calibration mass and a OHAUS Pioneer PX Analytical balance that state will be used in year 2 of the event. Is this yr 2? We are new to the competition and do not know which yr of this event we are entering. Thanks for your help.	There will be a new version of the lab event posted by the end of January. For 2026 we will not be using the balance or the 50 gram weight.	1/6/26
Is there going to be a new tutorial video?	No there will not be a new tutorial video.	1/27/26
1) Phosphorus Item 3 refers to a set of 3 test vials in each sub-bullet, and it's inferred that this is done for both standards, so 6 vials in total. Can the first set of vials be prepared and the timer started before the second set is fully prepared? Section 3.f indicates ALL samples need to be in the rack, but all previous steps only referred to the 3 vials per standard. 2) Is 3.25 acceptable to use in order to pipet 3.26mL? The pipets range in 0.05ml increments, so 3.26 is impossible to set. 3) Can the 1-5mL pipet be used to add 0.5mL to the phosphorus vials? The pipet goes to that range, but is rated 1-5mL.	Yes your first set of vials can be prepared and the timer set while you are getting the second set of vials ready. Once the second set is done the timer will have to be reset for those so they process the full 3 minutes. Yes you can set it as close to 3.26 as possible You can use it but we can’t guarantee the accuracy of that pipet since it technically goes down to 1.0 there is another pipet 0.2-1.0 ml that could be used instead.	1/28/26
Can you add the pillow packs to the sample cell before you add the sample for the chlorine test.	No you need to follow the 8167b Hach procedure that states to add the pillow packs to the sample. So you will need to ensure that the sample is in the sample cell before you add the pillow pack to the sample cell.	2/2/26
Can pipettes with new tips attached be placed on the table after setup?	Pipette tips can ‘t be placed on pipettes during the 2 minute set up. After the event starts you can put tips on the pipette and place the pipette on the table.	2/5/26
Can you provide clarification on the statement in section 2 c & d Phosphate standard preparation - “In the challenge you will be given two known PO4 concentrations that will be prepared from the 100mg/L PO4 secondary standard ” V1 = To be determined at the challenge C2 = To be determined at the challenge It is unclear if this will be determined by the judges or if this is something we need to determine during the challenge. After reading the event description V1 reads like the it’s determined via the team during the challenge. And C2 reads like it is provided by the judges?	The judges will tell you which 2 concentrations between 2 and 14 mg/L PO4 they want you to make C2 so then you will need to figure out the V1.	2/5/26
At what point will the judges be giving us the 2 concentrations, will it be during set-up or when the event starts?	You will be given the concentrations during the 2 minute set up.	2/9/26
Will there be an example of the concentration/volume math for the phosphate section be made available?	(This has been updated with the 3/4/26 answer) C1V1=C2V2 C1= 1000 which is stock standard V1= what you are solving for C2= is the 2-14 mg/L ( say you are given 4 mg/L) V2= 100ml 1000(V1)=4X100 1000(V1)/400 V1=0.4mls	2/12/26
for the po4 what amount of time will be taken off if you get both targets correct or only one of the targets correct?	90-110% for each PO4 target and the residual chlorine std you can get 30 seconds back 80-120% for each PO4 target and the residual chlorine std you can get 15 seconds back	2/13/26
Is the bonus time 30 seconds each sample or 30 seconds total?	You can get 30 seconds per working standard 1 and working standard 2 along with 30 seconds for the Residual Chlorine as well.	2/17/26
Once we are done using cylinders, beakers, flask, etc., do we have to rinse them before we put them into the tray? Since there is added flasks and beakers, will there be a new table layout?	No you don’t need to rinse the glassware before it goes into the trays. Potentially after South Carolina event I will post new pictures.	3/4/26
According to the procedure the known C1 value is 100, for the phosphate math. In a previous question you said the value of C1 was 1000. Can you clarify please?	This answer supersedes my previous answer on 2/12/26. They have the 3067 ppm stock standard. They need to make a 100 ppm secondary standard. C1 V1 = C2 V2 (3067 ppm) V1 = (100 ppm) (100 mL) V1 = 3.26 Then they take the 100 ppm secondary standard they made, to make a 2 ppm standard, for example, so: C1 V1 = C2 V2 (100 ppm) V1 = (2 ppm) (100 mL) V1 = 2 mL	3/4/26
Do you need to label and rinse a beaker if it is not used during the run? i.e. if the TAP beaker isn't used during the run does it still need to be labeled and rinsed with tap and DI?	No you don’t need to label and rinse glassware you don’t use but if anyone grabs it and uses it without it being labeled and rinsed it will be a penalty.	3/10/26