Thanksgiving Kitchen: Keep Your Sink, Disposal and Septic System Happy

Holiday scraps that clog a kitchen drain

A disposal only chops food; the pieces still have to clear the trap and the line under the slab. The usual troublemakers:

• Drippings, pan gravy, butter and bacon fat: runny while warm, they harden like candle wax a few feet down the pipe.
• Peels and leftover mashed potatoes: the starch turns to paste in the trap.
• Rice, dressing and rolls: they keep swelling with water after they go down.
• Turkey bones and pecan shells: hard enough to jam the grinder.
• Celery and onion skins: stringy fibers that wrap around the moving parts.

What SAWS says about holiday grease

San Antonio Water System boils its household grease advice down to three words: scrape, pour, wipe. Scrape solids into a lined trash can, pour cooled liquid fat into a container with a lid, and wipe pans with a paper towel. SAWS likens hardened grease in a sewer pipe to cholesterol in an artery, and it counts milk, salad dressing, shortening and even cake frosting as grease.

Hot water and grease-cutting soap don't fix it; SAWS says the fat just congeals again once the water cools.

Fryer oil is too much for a coffee can. The City of San Antonio's Household Hazardous Waste Drop-Off Center at 7030 Culebra Road accepts cooking oil; bring a recent CPS Energy bill showing the Environmental Fee and a photo ID. It's closed Thanksgiving Day and the Friday after, so cap the cooled oil and drop it off later. Outside San Antonio city limits, seal the cooled oil in its jug for the trash. Restaurants follow SAWS's separate Fats, Oils & Grease Abatement Program; see grease trap service.

Septic-safe habits for homes on acreage

Much of La Vernia inside city limits drains to the city sewer, run by its Public Works Department. On acreage toward St. Hedwig, Stockdale and Sutherland Springs, many homes send every drop to a septic tank instead. TCEQ, the state agency over septic (OSSF) systems, notes that organic overloading most often starts where food is prepared.

• Use the disposal sparingly. The EPA says ground food means the tank needs pumping more often.
• No oil or grease in any drain, per the EPA.
• Skip the additives. TCEQ advises against chemical additives and so-called enzyme products.
• Park guests off the drainfield. TCEQ and the EPA both say not to drive or park over it.

If the tank is due, have a TCEQ-registered hauler pump it before company comes.

Guests, extra showers and laundry

• Stagger showers. A line of guests can empty a tank-type water heater faster than it recovers, so split them morning and evening.
• Spread out the laundry. The EPA tells septic owners to spread washer loads across the week. Wash guest sheets before arrival, not all on Friday.
• Put a bin in every bathroom. Wipes belong in the trash, even ones labeled flushable.
• Check for a silent toilet leak. TCEQ's check: put a few drops of water-based dye in the tank; color in the bowl within 10 minutes without a flush means a leak, and on septic every leaked gallon runs through the tank to the drainfield.

A heater that rumbles or runs short is worth a water heater repair before guests arrive. See also no hot water and our freeze prep checklist for La Vernia and Wilson County.

Keeping the disposal running all day

• Cold water on while it grinds and for a few seconds after.
• Small handfuls at a time.
• Empty it before the dishwasher drains, since most dishwashers drain through it.
• No chemical drain openers. The EPA warns septic owners off them too.

If it hums but won't turn, switch off the power, work the hex socket underneath with the wrench that came with it, and press reset. Never reach inside. If it keeps jamming or leaks, see garbage disposal replacement. A sink that's already slow in early November, common in older homes on San Antonio's east side and in La Vernia's original town, deserves drain cleaning a week or two ahead. See also preventing clogged drains.

If the kitchen sink backs up on Thanksgiving

1. Shut off the faucet and pause the dishwasher.
2. Check the other drains. A gurgling tub or a rising toilet points to the main line or the line to the septic tank, so stop using water everywhere.
3. Plunge with a flat cup plunger, the second basin sealed with a stopper or wet rag. Never plunge after using a chemical opener.
4. Call if it won't clear. A slow drain or other sink repair can be booked at a time that suits you.

On SAWS sewer, SAWS asks you to have a licensed plumber camera the line and clear your side, then report the backup so a crew can inspect its main. If the plumber finds the blockage beyond your property, SAWS's Sewer Lateral Reimbursement Program may repay the normal charges for locating it. On septic, we clear a blocked house line; a full tank is a job for a septic company. See sewage backing up in the tub.

Thanksgiving kitchen and septic FAQ

Get your drains ready before November 26

Call (830) 475-2604 or use the contact page to book a drain check or disposal repair in La Vernia, Floresville, Seguin, Schertz, Cibolo or San Antonio. The coupons page lists $50 off drain cleaning, a $0 dispatch fee with a repair or replacement, and 10% off for seniors, military, first responders and healthcare workers.