Portable restroom rental stock and supplier guide

What to take away

This is general operating guidance, not legal, environmental or tax advice. Chemical handling, storage and wash-water discharge are regulated locally and by the product manufacturer, so confirm both before you set a standard.

What counts as stock here

A rental yard's stock is not the fleet. It is everything the fleet consumes, from a box of Walex Porta-Pak deodorizer packets to the cam-and-groove gaskets on a suction hose.

The last line catches new operators. Available waste capacity behaves like stock: it depletes across the day and, once it is gone, nothing else on the truck matters.

Satellite Industries and PolyJohn Enterprises both build portable restrooms and sell the paper, deodorizer and replacement parts that go into them. One invoice and one lead time can cover most of a service truck's consumables.

The reorder point, worked in named terms

Weeks are the wrong unit because demand here is not weekly. Cycles are the right one.

Let U be the number of units you are servicing, V the number of service visits each unit receives in a typical week, and Q the quantity of an item consumed per visit. Then weekly consumption is U times V times Q.

Let L be the supplier's lead time in weeks, and B a buffer expressed in weeks of cover rather than in units.

Reorder point = U x V x Q x (L + B).

The reorder point moves whenever you add units or change the service interval. Recalculate it when the fleet grows, not once a year.

Run the arithmetic line by line, because L differs by supplier. A box of Walex Porta-Pak packets and a set of door springs from McMaster-Carr do not sit the same distance from your yard; McMaster-Carr ships in-stock catalog items the same day.

B is where your judgment lives. A supplier reliable for three years still earns a buffer, because the failure you cover is a truck that cannot leave the yard.

Lead time is the number to ask about, not price

Get the lead time for every line in writing, and get the second answer too: what the lead time becomes in your busy season, when every operator in the region orders the same week.

Rank your lines by what a stockout does.

Buy depth in the first two ranks and buy responsively in the fourth. Most operators do the reverse, because the fourth rank is where the interesting purchases are.

Prices matter less than lead time, but the typical figures are worth knowing. Drop-in deodorizer packets usually run 50 to 90 cents each in a 100-packet box.

Liquid concentrate typically costs $12 to $25 a gallon in five-gallon pails. Scott JRT jumbo roll tissue, sold by Kimberly-Clark Professional, typically runs $40 to $60 a case of 12 rolls.

Ansell HyFlex and Kimberly-Clark KleenGuard gloves typically run $1 to $3 a pair through Grainger, Fastenal or Uline. Cam-and-groove gaskets from Dixon Valve or Banjo typically cost 50 cents to $1.50 each in bags of 25.

The disposal outlet is a supplier with no substitute

Every other line on your stock list has an alternative source within a day. The receiving point does not. If it closes for maintenance, restricts hours, changes what it accepts, or reaches capacity, your route stops regardless of how well stocked the truck is.

Manage it as the dependency it is. Know the hours and acceptance conditions. Know what paperwork rides with a load and keep it.

Know the next nearest alternative and what the extra drive costs before you need it. Ask the site operator how closure notice is given, and make sure it reaches you, not an unmonitored mailbox.

Most receiving points are municipal wastewater plants with a septage station. Tipping fees there typically run $0.05 to $0.15 a gallon, or a flat charge per load.

RV dump stations at many Love's Travel Stops and Pilot Flying J locations take small volumes, usually free to about $10. They are not a route solution for a vacuum truck, but they cover a single unit.

The right time to find your second receiving point is the week your first one is working perfectly.

Chemical and consumable storage

Chemical belongs somewhere dry, temperature-appropriate and separate from the wash area, with the manufacturer's handling instructions available to whoever loads the truck. Paper belongs somewhere dry, full stop; a pallet of damp paper is a total loss.

Storage is a safety matter, not tidiness. OSHA's guidance on safety and health programs frames the work as identifying and fixing hazards before an incident does. A chemical store arranged so the wrong container cannot be grabbed in a hurry applies that principle.

Every chemical supplier, Walex and Satellite included, publishes a safety data sheet for each product. That sheet belongs with the container, not in an office.

Sanitation your customers must provide on their own sites falls under the federal sanitation standard for workplaces and any state plan or permit condition that applies to them.

Counting, and when to do it

Count consumables at load-out and at the end of the day, because that is when a discrepancy is still explainable. Count wear parts weekly against the set level.

Count the fleet on a schedule that matches how fast units move. For standing orders that can be monthly; for event stock it has to be after every weekend.

Record consumption against service cycles rather than against dates. That is the only form in which the number is useful, because it lets you recalculate reorder points when the fleet changes rather than guessing.

The IRS on which records a business keeps leaves the system to you provided it clearly shows income and expenses and keeps the documents supporting purchases. In practice the same records give you your consumption history, which is the input to every stocking decision you will make.

Protecting the system the stock lives in

Once ordering, consumption and fleet location sit in software, that system is a business record and a target. A small operator does not need a security program; it needs the basics done, kept current, and known to more than one person.

NIST's small business quick-start guides set out those basics in a form written for organizations without a technology department. The part that matters most here is recoverability.

If the record of which unit is on which site is lost, the fleet effectively disappears. Keep an export you can read without the software, and test that you can actually open it.

Suppliers, and what to have in writing

Three things belong in writing with every supplier: what the lead time is, what happens when they cannot meet it, and whether the specification can change without notice. That third one matters more than it sounds, because a quietly revised part means your shelf stock no longer fits.

Ask Satellite Industries and PolyJohn Enterprises for the current part number and revision before you buy a shelf's worth of door springs.

Hold a second source for anything in the first two ranks above. It can be an account you rarely use, but it must exist and a person there must answer.

For hardware and fittings, the catalog houses carry the second source. McMaster-Carr stocks springs, hinges and gaskets; Dixon Valve and Banjo cover cam-and-groove couplings and the gaskets that fail first.

Suction hose is the harder line. Kanaflex and Kuriyama's Tigerflex both sell heavy-wall hose for vacuum service, and either one is a workable second source for a section that fails mid-route.

The Portable Sanitation Association International keeps a supplier directory organized by category. The PSAI annual convention and the WWETT Show in Indianapolis are where most of these companies exhibit.

The equipment side of these decisions is in how the fleet and the truck are chosen. The demand pattern the stocking has to serve is in how the market is read before you start.

Common questions

How much buffer stock is sensible?

Enough to cover the supplier's stated lead time plus the amount that lead time stretches in your busiest month. Ask the supplier for both numbers rather than estimating the second one.

Should consumables be bought in bulk?

For paper and chemical, usually yes, provided you have dry storage and the product does not degrade. For anything with a shelf life or a specification that changes, buy to your reorder point instead and take the small price penalty.

Who should own ordering?

One named person, with a second who can do it. Ordering that belongs to whoever notices the shelf is empty is ordering that fails during the week everyone is busiest.

Where is the shortest list of suppliers?

The PSAI member directory sorts companies by category: units, deodorizer and paper, parts, and hose and fittings. Grainger and Fastenal cover gloves and cleaning chemicals from a local branch, which shortens the rest.

What is the most common stocking mistake?

Sizing stock to an average week. The average week does not exist in this trade, and the shortage always arrives in the week when a shortage costs the most.