4.3 Mixing, Loading, Spills & Emergency Response (Pes 805)

4.3 Mixing, Loading, Spills & Emergency Response (Pes 805)

Mixing and loading is where applicators get hurt. It is the only routine task in which you handle undiluted concentrate, often at eye or chest height, often in a hurry, often alone. New Hampshire regulates it in its own part of the rules.

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Pes 805.01 - the six mixing and loading requirements

Any person engaged in the mixing or loading of pesticides must comply with all six:

+------------------------------------------------------------------+
|  PES 805.01 MIXING AND LOADING                                   |
+------------------------------------------------------------------+
|  (a) FOLLOW the pesticide label recommendations                   |
|  (b) NOT within 400 FT of gravel packed wells used for public     |
|      water supply, or 250 FT of other wells so used               |
|  (c) NOT within 75 FT of surface water or PRIVATE water wells     |
|  (d) MAINTAIN backflow prevention by an anti-siphoning device     |
|      on the fill hose or water supply line                        |
|  (e) KEEP the fill hose ABOVE the surface of the water/chemical   |
|      solution in the tank AT ALL TIMES                            |
|  (f) CLEAN UP spills IMMEDIATELY to prevent pesticides from       |
|      soaking into the ground                                      |
+------------------------------------------------------------------+

The 75-foot number is the one candidates miss. New Hampshire has no general application setback from private wells, but it has a 75-foot mixing and loading setback from private wells and from surface water. Keep the three distances straight: 400 / 250 / 75.

Pes 805.02 - the exemptions

• Chemigation mixing or loading is exempt from (b) and (c) if the total capacity of pesticides at the chemigation mixing and loading site is 5 gallons or less of liquid or 50 pounds or less of dry pesticide, and secondary containment is provided that is constructed of material compatible with the pesticide, has an outside edge at least 10 feet from the water supply including any wellhead or surface water source, and is capable of containing at least 110 percent of the volume of the pesticide container.
• Mixing or loading on a containment facility approved by the Natural Resources Conservation Service and installed before April 13, 1993 is exempt from (c).

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Planning the mix

Compatibility

Before tank mixing, determine compatibility. Some combinations gel, separate, form precipitates that plug screens and nozzles, or become phytotoxic. Check the labels first; both labels must permit the mixture and neither may prohibit it.

When the labels are silent, run a jar compatibility test on a small scale before committing a tankload:

1. Use a clear quart jar and fill it with the same water source and at the same proportion the tank will use.
2. Add each product in the same order you will use in the tank, mixing after each addition.
3. Let the jar stand 15 minutes and look for flakes, sludge, gels, oily films, layering, or heat.
4. If the mixture separates but re-suspends with agitation, it may be usable with continuous agitation. If it forms solids or gels, it is not.

A standard addition order for a tank partly filled with water and under agitation is wettable powders and water-dispersible granules first, then flowables, then solutions, then emulsifiable concentrates, then surfactants and oils last, topping off with water. Add compatibility agents when the labels call for them.

Site selection

Choose a mixing and loading area that:

• is away from wells and surface water, and complies with the 400/250/75 distances;
• is not in a low spot where a spill would run to a drain, ditch, or stream;
• has an impervious surface where possible, so a spill can be recovered rather than absorbed; and
• is not upwind of workers, livestock, or occupied buildings.

Varying the mixing location within a field, rather than using one patch every time, prevents the concentrated loading that turns a mixing pad into a site management area under Pes 1002.

Handling the concentrate

• Put on the full PPE the label requires for mixers and loaders - typically the highest level on the label, and normally including a chemical-resistant apron.
• Open containers carefully, below eye level where possible, on a stable surface, using a sharp tool on paper bags rather than tearing them.
• Measure accurately with dedicated equipment that is never used for anything else, and rinse measuring devices into the tank.
• Transfer carefully: pour with the container opening low and downwind, and use closed transfer systems or water-soluble packaging where available. Pes 502.06 requires closed-system protections for chemigation.
• Keep the fill hose above the liquid surface - Pes 805.01(e) - and never walk away from a filling tank.

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Emergency response: the three Cs

Every spill, whatever the size, follows the same sequence. Put on appropriate PPE before responding.

1. Control

Act immediately to stop the flow.

• Place small leaking containers inside larger ones.
• If a drum is leaking, try to plug the leak, then transfer the contents to a sound container.
• On a pressurized system such as a sprayer, turn off the pump.
• Never leave the site unattended.

2. Contain

Keep the spill from spreading or reaching water.

• Berm the area with a shovel to keep material out of drains and waterways.
• Use absorbent material - a spill pillow, absorbent clay, sawdust, or cat litter - around and then into the spill.
• A spill contained on the surface is far easier to clean than one that has entered a water body.

3. Clean up

• Sweep up absorbent materials and other contaminated items and place them in a drum for disposal as pesticide waste.
• On concrete or asphalt, neutralize the surface following the SDS instructions or the manufacturer's direction.
• On soil, the state pesticide regulatory agency will specify what is required - commonly removal of the top 2 to 3 inches of contaminated soil.

If the spill reaches water

Contact the state agencies responsible for streams and fisheries and for pesticides immediately. They need lead time to warn downstream drinking water users and to prevent livestock poisoning. In New Hampshire, if the water is a public water supply surface water or tributary, Pes 502.04(i) requires that you report verbally immediately and in writing within 5 days to the Division of Pesticide Control. CHEMTREC (1-800-424-9300) provides 24-hour emergency response information for transportation incidents.

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Fires

A pesticide fire is a different problem from a spill, because the hazard is in the smoke and in the contaminated firefighting water.

• Call 911 first. Do not attempt to fight the fire yourself and do not re-enter the storage facility to salvage product.
• Tell responders what is stored, in what quantities, and where, and give them labels and SDSs. Pre-file that inventory with the local fire department before a fire happens.
• Berm to contain contaminated runoff water, which is often a larger environmental problem than the fire.
• Reduce fire risk in advance with a fire-detection system, separation from heat sources and ignition sources, good housekeeping, and a posted storage warning sign.

The backbone of any emergency response plan is outlining the sequence of actions to take in a crisis - who does what, in what order, and who calls whom. Knowing where labels and SDSs are kept and having a designated responder support that sequence but do not replace it. Afterwards, make a detailed written report of what happened before, during, and after the incident.

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Worked example

A loader tips a 2.5-gallon jug of emulsifiable concentrate on a gravel driveway 50 feet from the farmhouse well while filling a sprayer.

1. The mixing site was already unlawful: Pes 805.01(c) forbids mixing or loading within 75 feet of a private water well.
2. Control - set the jug upright, cap it, shut off the pump, and stay on site.
3. Contain - berm the downhill side with a shovel before anything else, then ring the spill with absorbent.
4. Clean up - sweep the saturated absorbent into a drum for disposal as pesticide waste; gravel is not an impervious surface, so the contaminated top 2 to 3 inches will likely have to come out at the state agency's direction.
5. Pes 805.01(f) requires the cleanup to happen immediately, precisely to prevent soaking into the ground and reaching the well.
6. Document the incident, including product, quantity, time, weather, actions taken, and notifications made.