HowTo – Lake sampling

Priority: low
Updating: mature

Change log:

Date	Who	Comment
2021 03 04	Sp17	First version from memory of earlier practice.
2022 06 08	Sp17	Second version adapting to us collecting the samples from boats and bridges.
2022 07 20	Sp17	Refined based on agreement with volunteer Jan Andersen of Lake Waccabuc. This follows CSLAP practice more closely than we did in earlier projects.
2022 08 18	Sp17	Refined based on agreement with volunteers Jane and Doug Conroe of Chautauqua Lake.
2022 09 16	Sp17	Retitled to put Lake first. Added a section about lake tributary sampling. Backed off to 85% because of the tribs sampling which we have not yet practiced.
2023 08 24	Sp17	To 100% since we are well practiced. Adapted to Markdown. Added notes about sampling from moving boat, such as ferry. Generalized bridge sampling to include long docks.

Cross references:

1. Objectives:

Collect representative samples from lakes or lake-related streams at predetermined locations, at prespecified depths, and on specified types of days.
Preserve samples against chemical change from the time of collection until they are shipped to Cornell for supplemental preservation and freezing.
Obtain field measurements from lake water to accompany samples.

2. Roles:

Volunteer samplers
- Have boats, sampling devices.
- Use CSLAP field log forms to record sample times, dates, and other context.
- Samplers collect samples and label them, adding the date and time to the label.
- Samplers store samples frozen until shipment to Cornell.
Cornell as support to volunteer samplers
- Pay for a rented freezer at lake samplers if requested, for storing samples. (Frowned upon because of small amount of water and only one or two samplings per year.)
- Provide fresh sample containers, partly preprinted sample labels, and any other supplies needed.
- Optional if volunteers wish: Provide field blank supplies, this HowTo, and deionized water.
- Store samples frozen after receipt from volunteers. Thaw, make aliquots for DEC lab. Ship frozen to DEC lab.
- Return full detail DEC analytical data, with interpretations, to the volunteers.
NYSDEC Division of Water arranges for training, including peer training, of samplers. This is routine activity within CSLAP.
- Note: In earlier samping 2013-2015 the Bureau of Pest Management made all arrangements with the Division of Water and the Federation of Lake Associations to select lakes. In this current project, to reduce interorganizational communication costs and time lags, Cornell is recruiting Lake Associations directly.
Cornell as samplers of some lakes, no involvement of volunteers at such lakes and no involvement of Division of Water.
- Schedules and collects samples from boats or bridges.
- Make field measurements of pH, temperature, and specific conductance.
- Stores samples in freezer after return to Ithaca.
- Make aliquots for DEC lab.
- It there were any local partners in field work, return data from DEC lab to partners.

3. Collection

Samples are collected following CSLAP protocol using a depth-controlled Kemmerer sampler; there is one possible extension:

Fill and dump sampling device once before re-immersing and drawing the sample. This is to reduce cross-contamination between consecutive samples. This is at the option of the lake samplers. (Generally the sampler is well rinsed with lake water at the sampling point by immersing it while open.)
Sampling device should be rinsed with potable tap water (outdoor hose tap is OK) after a sampling session. A session is all samples from one lake. If there is more than one lake on a day, rinse between lakes. Cornell sampling personnel rinse with deionized water.

The day of sampling is at the choice of lake volunteers, presumably when CSLAP samples will be taken. For Lake Waccabuc, by agreement one pair of samples per year will be taken during a routine CSLAP sampling round, and one pair of samples per year will be taken one or two days after a storm to represent times of greater washoff of pesticides from watershed land into lakes. The latter pair conforms to the 2013 and 2015 projects. Chautauqua Lake volunteers collected one round of samples on a typical summer CSLAP sampling day.

Sampling locations are agreed in advance between the samplers and Cornell, influenced by the NYSDEC Bureau of Pesticides. Initially, there is one sample per session representing the lake or its outlet, and one sample per session representing a major inlet or a major pesticide user. CSLAP custom represents the lake with a position over the deepest section of the lake. It is best if sample locations are chosen by the volunteers from their knowledge of the lake. The locations should be largely consistent per lake for the life of the project. Chautauqua Lake samplers collected samples at two customary CSLAP locations representing distinctly different “basins” of the lake, and samples at two depths at one location representing a major institutional water supply intake. 2023 Chautauqua Lake samples to be collected by Cornell will include the outlet and the narrow channel collecting the northern and southern lobes of the lake, thus being closer to the original NYSDEC specifications.

The depth of sampling is the CSLAP standard for shallow samples, 1.5 meters below the surface and extending downward for the length of the sampling device. Cornell uses a 2.2L Kemmerer sampler which may be longer than the samplers used by volunteers. 2022 Chautauqua Lake samplers collected a fourth sample deeper at the institutional water supply intake area.

4. Equipment needed:

If sampling from boat:
- Boat.
  - If inflatable, matching air pump(s). Charged battery for pump if separate from pump.
- Paddles; or motor with fuel or charged battery.
- Anchor with rope.
- Life jackets, one per person.
- Patching kit if using inflatable.
- Note: Boats with motors must be registered according to NYS law.
Insulated box with ice to chill samples after collection. Cornell-provided shipping containers may be used.
pH/temperature/conductance meter to make field measurements. (Conductance is optional for volunteers, mandatory for Cornell sampling.)
When applicable: Kemmerer lake and deep stream water sampler. In its customary carrying case, cleaned in advance. Rope is graduated in half meters measured from the top of the sample container’s interior, to 2.0 meters. Kemmerer may also be used from bridge or long dock in deep inlets and outlets.
Shallow tributary and outlet stream sampling from low bridges (up to 15 feet above water): Peristaltic pump, thick walled hose, weight at bottom of hose.
Container for deionized water if field blank will be taken.
Bucket for tap or deionized water for field cleaning of sampler.
Waterproof logbook with compatible pen.
Measurement container for meter. This is filled with sample water from the Kemmerer and the meter used to read within it. Typically a cut-off 250 mL nalgene bottle.

5. Supplies needed:

CSLAP or equivalent form to record sample metadata. Preferably waterprooof paper with laser printing. (Cornell uses waterproof logbook and enters data into form on computer.)
Sample containers. Initially we use 2 to 3 250 mL Nalgene wide mouth bottles. The count per sample may be limited by volunteers’ freezer capacity.
Preprinted waterproof label for each sample container. Cornell provides preprinted waterproof container labels to volunteers.
Sharpies for marking containers when dry. Jetstream or equivalent pens for writing on waterproof labels (write when labels are dry, allow some drying time.)
Optional: Paper towels for drying containers before writing on them.
Tap or deionized water for rinsing Kemmerer sampler or peristaltic pump hose in field after last sample from a lake. (CSLAP protocol is followed by volunteers; Cornell samplers use deionized water rather than tap water.)
(if by Cornell) Soapy and deionized water for cleaning Kemmerer sampler or pump hose after return to lab, before long term storage.
Calibration solutions for pH and conductance meter, CSLAP procedure for volunteers, Cornell follows meter instruction manuals. Solutions provided by Cornell to volunteers if requested.

6. Normal sampling protocol for lakes, including bridges on lakes (all Kemmerer sampler usage):

Generally two people are involved when sampling from boats. One person can sample safely from bridges over lakes.
Drive to location of boat launching or other sampling position.
If boating, pack and launch boat and go to sampling position.
- If shore/bridge position, move sampler and containers to sampling position. Be on the downstream side of a bridge so sampler is carried by current away from the bridge, not under the bridge.
If boating, anchor near the intended sampling position. A person other than the sampler can do station-keeping via paddles or motor if there is difficulty keeping still with only the anchor.
- Special case: sampling from a moving ferry. Arrange with pilot in advance to sample from side or stern, to avoid interference with motive power. This does not require a second person.
Make sure that you do not lose the $600+ Kemmerer sampler; i.e. the sampler’s rope should be fastened to a person, the boat, or bridge.
Open Kemmerer sampler and “cock” into open position by pulling both top and bottom until there is a click. It is okay to do this with the sampler oriented sideways. Avoid touching the interior of the sampler including the rims and insides of the two ends.
Dangle open sampler from rope to planned depth – usually this is 1.5 meters below the water surface. Read depth from the rope as it enters water; rope should be graduated with a prominent mark at 1.5 meters.
Raise and lower the sampler a little above and below the target depth; this is effectively rinsing any remains of the prior sample or washwater with lake or inlet/outlet water near the target depth. In an inlet or outlet the sampler may rest on the bottom at a slight angle, but not entirely on the bottom; in latter case the 1.5m depth criterion should be relaxed.
Rope must be taut, which can require care if sampling from a stream with the sampler’s bottom resting on the stream bottom. Release the messenger down the taut rope to trigger the sampler’s closure.
Bring up the sampler without banging it against anything.
While holding the sampler dangling from its rope, ready receiving container(s). Position exit valve over a container. Open valve (parallel to spout) to put some rinse water into sample container. If using multiple containers, fill each partly with rinse water (1/4 to 1/2 full). Close valve and continue holding sampler; should retain most of contents for the final sample. If measuring field parameters, also treat measurement container like a sample container - rinse it before filling.
Shake the sample containers cap-on, dump rinsate back into lake. Swirl lake water in the measurement container and dump.
Final sample: Fill the sample containers and measurement container from Kemmerer. Cap sample containers.
Measure field parameters in measurement container.
Dump remaining water in Kemmerer and measurement container into lake.
Repeat above for other sampling locations within lake.
After last sample at a lake, rinse the Kemmerer interior, exterior, and rope with tap washwater or deionized water. Put sampler wet back into carrying box. Rinse measurement container with tap water.
If Cornell is sampling: After all lakes of a trip are complete and return to Ithaca, do Kemmerer sampler cleaning protocol.

7. Sampling protocol from bridges or docks, using peristaltic pump:

Note: If water is deep enough (around 3 meters), the Kemmerer sampler may be used from a bridge or dock.

One person can sample safely from bridges over lakes. Second person optional.
Drive to location of sampling position. Park in authorized and safe location for unloading.
Move pump, hose, weight, and containers to sampling position. Be on the downstream side of a bridge so hose is carried by current away from the bridge, not under the bridge.
Fasten weight to hose below hose opening if weight is not already present. Leave a few inches between hose opening and top of weight. Mounting can be done via zip ties clasping weight’s rope to hose.
Dangle hose into watercourse at thalweg, so the opening is about 1/3 of the total depth. Record the depth of immersion. [need discussion of retention rope] It is OK for the weight to be resting on the bottom, as long as the hose opening is pointing downward. Attach to pump intake side.
Pump to waste a few liters of stream water to flush remains of prior sample from hose.
Rinse sample bottles with water from pump, dump it.
Fill sample bottles and cap, leaving airspace enough for freezing expansion.
Measure field parameters in measurement container.
After last sample at a lake watershed, rinse the hose inside by pumping through deionized washwater. Rinse measurement container with deionized water.

If Cornell is sampling: After all lakes of a trip are complete and return to Ithaca, do Kemmerer sampler and/or hose cleaning protocol.

8. Optional Field blank protocol, once per lake, when using Kemmerer.

(See Sampling from Monitor wells HowTo for the procedure to draw field blank using hose.) At option of volunteer samplers. At most once per lake over the project life.

This is intended to check the carryover between consecutive samples.
Cornell will provide deionized water to samplers to use in drawing the field blank. Cornell will retain some of that day’s DI water as a companion “lab blank”.
In the boat after at least one sample has been drawn: Partially fill the sampler with provided deionized water, and dump it. Fill a second time, then use that liquid to fill sample containers (with “field blank” label) as for conventional samples.
Field blank procedure.
- This will measure carryover from a prior sample, including simulated rinsing with new “sample” water. Should be done after the first sample of the day, in the field.
- Needs:
  - Instrument measurement container as used for prior sample on this trip.
  - Kemmerer as used for prior sample.
  - Roughly 3L of deionized water. Provided by Cornell if this is done by volunteers.
  - Container to receive the blank sample, labelled with blank identity, location, date, time. Provided by Cornell if this is done by volunteers.
  - Logbook and pen to record blank attributes and instrument readings.
Simulate rinsing with new sample:
- With sampler closed, stand on its bottom end on something clean so that the lower valve does not become soiled.
- Pull up the top seal without “cocking” it.
- Pour in just under half full with deionized water; reserve at least 1.2 L for the final blank sample and blank instrument container, including container rinses.
- Close top seal.
- Shake Kemmerer sampler to rinse the entire interior, drain through the bottom valve until empty.
Rinse sample container(s). Draw the sample
Pull up top seal again.
Pour in half full of deionized water (enough to make a full standard sample and fill the instrument container plus a little more for rinsing sample container).
Close top, seal.
Draw small amount rinse water from sampler into blank sample container(s) and instrument container through bottom valve. Rinse and dump blank sample container(s) and instrument container.
Draw blank sample into sample container, and draw enough water into instrument container to make instrument readings.
Drain to waste remaining deionized water though valve or open the top seal and dump.

9. Steps for volunteer sampling with shipment of samples to Cornell.

See also the Howto about shipping lake samples to Cornell:

Cornell ships or drops off all sampling supplies in advance. Replenish them on demand. Cornell provides partly filled preprinted waterproof labels.
Samplers decide when to sample. This can be extra water during regular CSLAP sampling.
Samplers collect, then freeze samples. Samplers maintain field notes.
Samplers store samples until shipment to Cornell.
Samplers ship to Cornell in the insulated box sent by Cornell originally, at Cornell expense.

Repeat 2-4 times per site over four years.

10. Safety in sampling from boats.

Generally only experienced boaters, all with good swimming capability, should be sampling in boats. CSLAP volunteers and a subset of Cornell personnel qualify for sampling from boats.
Two people are highly preferable for boat samples, one to stabilize the boat and make log entries, the other to draw samples.
- One person is OK for sampling from bridges and shorelines.
- One person may be able to sample from an inflatable rowboat which is more stable (but harder to propel) than a canoe or kayak.
Wear PFDs whenever in boat.
Avoid being in boat during major storms. Light to medium rain is OK. Heavy rain is marginal for sampling from bridges and shorelines only.
Don’t approach a dam or any concentrated outflow structure closely. Obey posted exclusion zones.
Avoid wakes of power boats.
If using inflatable boat:
- Make sure no air leaks before launching.
- Check for deflation while out on the lake.
- Carry quick patch repair kit and air pump while on lake.

11. Inflatable boat at Cornell

Inflating the Intex boat (Cornell (Pacenka loaner)):

Using a high capacity pump with cigar lighter 12V power. (May be powered from Jackery Battery or car.) Can also use Intex hand pump.
The three chambers are inflated in numbered order 1-3.
Inflate the floor chamber:
- Pull out the valve plug.
- Connect pump via the correct tip.
- Activate pump.
- Fill to moderately taut. (There is not a precise way to tell.)
- Quickly remove hose and insert the plug; air escapes until plug is back in.
Inflate chamber 2.
- Remove filling plug from valve. Ensure that concentric deflating valve is screwed on tightly.
- Connect pump via the correct tip.
- Have the 10 cm ruler ready; when the chamber is sufficiently full the 10 cm line on the chamber will stretch to 10 cm length. Deflated it is around
Inflate chamber 3; same as chamber 2. There is a separate inflation check ruler on each of chambers 2 and 3.

Deflating the Intex boat:

Open all three air valves.
Roll up from bow toward stern to squeeze out air. The floor valve may need to be squeezed for the last air to be expelled.