When the main sends it back up the floor drain

A gravity sewer works on slope, and the Delta does not have much of it. When heavy rain gets into a collection system faster than the system can move it, the line surcharges, the water level in the main rises above the house connections, and the lowest opening in the building becomes the relief point. That is almost never where anyone wants it.

Why the flat country makes this a rain problem

Crittenden County lies entirely on Mississippi River bottomland, with alluvial sediment more than a hundred feet thick beneath the surface and Sharkey clay on top of it. That clay is dark, heavy and slow-draining, productive for cotton and soybeans and unhelpful to a storm sewer. On flat ground with a shallow, seasonally high water table, rainfall does not soak away quickly and it does not run off quickly either. It sits, finds cracked joints, manhole covers and roof drains, and gets into the sanitary system as inflow and infiltration.

The volume that gets in during a heavy rain can dwarf the sewage the system was sized for. West Memphis has seen the extreme version: eleven days after the December 14, 1987 tornado, twelve inches of rain fell on the city in a single event. Nothing in the ground or in the pipe network handles that. When a main surcharges, every house connected to it below the new water level is on the wrong side of the pressure, and the first fixture to give is the lowest one, which is typically a basement or utility floor drain, then a first-floor shower pan, then a toilet.

1. You callOne number per county. The dispatcher takes the address, the ZIP and a short description of what happened.
2. A local crew calls backAn independent restoration contractor already working that county rings you directly and sets a time.
3. They look, then scope itNothing is priced from a phone call. The crew walks the building, takes readings, and writes a scope you can hand to your adjuster.

The other cause: a lift station that stops

Flat systems cannot rely on gravity all the way to the plant, so they pump. Lift stations collect flow at the low points and push it on, and when a station stops the line upstream of it fills. Mountain Home's own system illustrates how ordinary that vulnerability is: the city's wastewater treatment plant is receiving a $1,350,000 upgrade for ultraviolet disinfection and rebuilt headworks and bar screens, and several lift stations still run pumps that are twenty to thirty years old, alongside a $100,000 water and sewer master plan update.

A pump that has aged out is one failure mode. A power outage is another, and it is the one that turns a storm into a backup. The January 26 to 28, 2009 ice storm cut power to roughly 350,000 customers across the state at its peak, with about a hundred thousand still dark by February 3. A station without power and without a working generator backs up the collection line behind it for as long as the outage lasts, and the houses at the bottom of that run find out first.

Category three from the first minute

Water that came out of a sanitary main is grossly contaminated, and the trade calls that category three. There is no version of this loss where it gets treated as clean, no matter how clear it looked coming up the drain, and no amount of drying converts contaminated porous material back into sound material. The demolition line is set by what the water touched, not by how wet it is now.

The practical consequence is that most of the soft material in the affected area leaves the building. Carpet and pad come out and are disposed of. Wallboard is cut above the wetted height, allowing for the wick line, and the insulation behind it comes out over the full height that got wet. Particleboard cabinet bases, laminate flooring and upholstered furniture that sat in it come out. Solid framing, concrete, glazed tile and metal stay, because they can be washed rather than merely wiped.

Order of operations matters as much as it does after a river flood. Solids and contaminated water are removed, hard surfaces and framing are cleaned, an antimicrobial goes on what remains, and drying equipment starts last. Running air movers over contaminated material before it has been cleaned takes the contamination off the floor and puts it into the air, which is the opposite of the point.

The places it hides in a slab house

Most housing in Crittenden County is slab-on-grade, which changes where the water ends up. There is no crawl space for it to drain into, so it spreads across the slab and travels under things.

• Under sheet vinyl and vinyl plank, where a water-resistant wear layer traps contaminated water against the slab and hides it from view.
• Under and behind base cabinets and a vanity, through the open toe kick, into a closed void with no airflow.
• Into floor-mounted return ductwork and any supply run cast in or under the slab, which will redistribute whatever settles in it the next time the system runs.
• Into the wall cavity at the bottom plate, where wallboard wicks it upward out of sight.
• Along the slab under a door threshold into the next room, which is why the affected area is usually larger than the room the backup happened in.

Prevention that actually works on this ground

A backwater valve on the building sewer is the one device that addresses the mechanism directly. It lets flow out and closes against flow coming back, so a surcharged main cannot use the house as a relief point. It has to be installed where it can be reached and cleaned, and it has to be checked, because a valve that has silted open does nothing.

The other useful measures are unglamorous. Roof downspouts and any sump discharge should be routed away from the building and never tied into the sanitary line, since that is inflow the system was not designed to take. Cleanouts should be findable. And in a house that has backed up before, keeping the lowest fixtures free of stored belongings costs nothing and saves the contents that would otherwise be sitting in it.

Where the cause is a blockage in the house line rather than a surcharged main, the fix is a plumber and a camera, not restoration equipment. Roots in a clay lateral, a bellied section that has settled in soft ground, and grease are the common ones, and all three recur until the line itself is dealt with.

Questions people actually ask

Use the number above and the contractor will take it from there.