Placing a porta potty on Upstate red clay without sinking or tipping

Why is Upstate red clay hard on porta potties?

Most Upstate land sits on Cecil series soil: a sandy loam topsoil over red kaolinite clay. On many lots the topsoil has eroded away, leaving the red clay exposed. Cecil clay compacts easily and turns slick when wet. Anderson averages about 50 inches of rain a year. A unit set on bare wet clay can lean, settle or slide.

The official USDA description of the Cecil soil series explains the layers. In plain terms, red clay drains slowly. Rain sits on top, and the top inch turns to grease.

New construction lots are the worst. Graders strip the topsoil, and heavy equipment churns the clay into ruts.

When is the ground wettest in the Anderson area?

The wetter season in Anderson runs from about March 24 to August 20. May is the rainiest month, with about 4.3 inches. Anderson gets about 50 inches of rain a year in total. Summer thunderstorms can drop an inch in an hour, so even a dry July lot can turn soft by afternoon.

Plan for wet ground on any rental between late March and late August. That covers spring building, graduation parties, summer reunions and early football season. Fall and winter bring drier spells, but a week of rain softens clay in any month.

What should go under a porta potty on clay?

A firm, flat base keeps a unit level on clay. For a weekend event, a sheet of 3/4-inch plywood works well. For a long jobsite rental, a small gravel pad is the best choice. A driveway edge or concrete slab works anywhere. The base should be larger than the 44 by 47-inch footprint.

How level does the spot need to be?

The spot should be level enough that a ball would not roll on it. A 165-pound unit on a slope rocks when someone steps in, the door can bind, and the tank contents shift toward the low side. Pick the flattest spot within reach of the truck. Tell us about slopes, steps and retaining walls when you book.

On sloped lake lots and hillside yards, the flat spot is often near the driveway or the top of the lot. That's usually the best place anyway, since the truck can reach it. Don't stack blocks or shims under a unit; uneven support can crack the base.

How do you anchor a porta potty before a summer storm?

Summer thunderstorms bring strong gusts across open Upstate fields. A standard unit weighs 165 pounds empty and is tall and narrow, so wind can tip one on soft ground. Ask us to stake or strap the unit when you book for an open, windy site. Units on level, firm ground tip far less often.

Sites most at risk: open pasture, hilltops, lake coves and new subdivisions with no trees left. Set the unit beside a building, fence or tree line when you can, with the door facing away from the prevailing wind.

If a unit tips, keep people away and call us. We clean, sanitize and reset it.

Can the delivery and pump trucks reach the spot after rain?

Our truck parks as close to the spot as possible, and a dolly carries the unit the rest of the way. The dolly needs a 10-foot clear path. A loaded truck can rut a wet clay lawn, so a gravel drive or firm route is best. Units are 44 inches wide, too wide for a 36-inch gate.

The pump truck comes back every week on longer rentals. Pick a spot that will stay reachable as the job changes, not one that gets boxed in by a dumpster or lumber pile.

What placement mistakes cause tipping on clay?

We see the same 4 placement mistakes over and over. Units get set on fresh fill dirt beside a new foundation. Units sit on the edge of a ditch or swale. Units go on the downhill side of a sloped driveway. Units get placed beside an open utility trench. Each spot can wash out after one heavy rain.

Fresh fill hasn't settled, so it sinks unevenly. Ditch edges and swales carry runoff, which undercuts the ground. Pick undisturbed, high ground instead, even if it's a few steps farther from the work.

How should a builder plan placement for a long job?

Builders should pick a spot near the construction entrance on undisturbed ground, then lay a gravel pad about 6 by 6 feet. The spot should stay clear of trenching, grading and material drops for the whole job. If the site plan changes, call or text us to reset the unit; crews may not move units.

Most builders put the unit near the road, where the pump truck can reach it without driving onto the lot. That also keeps the truck off soft clay. See construction site toilets and our home remodel guide for more.

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