Owner questions

Septic questions from Bandera County owners

These are the questions that come up once you actually own a system out here, mostly the aerobic ones, because most of the county runs aerobic. The basics like how to tell which system you have and how often a conventional tank needs pumping are answered on the home page, and the money questions are on the cost page. This page is the care and keeping of the system you already have.

What should I never flush or pour down a septic system?

The short list of things to keep out: grease and cooking oil, wipes of every kind including the ones labeled flushable, paper towels, feminine products, cotton swabs, cat litter, coffee grounds, and harsh chemicals in any quantity. That last part matters more here than most places, because most of the county is on aerobic systems, and an aerobic system treats your water with live bacteria. It is not just a tank that fills up. It is a small biological treatment plant, and the bugs doing the work are alive.

Bleach, drain cleaner, paint, paint thinner, solvents, and a steady diet of heavy antibacterial cleaner all kill those bacteria. A normal amount of ordinary household cleaning is fine. Pouring a gallon of bleach down to clear a slow drain is not, because you are sterilizing the very thing that treats your effluent. Grease is its own problem: it does not break down, it coats everything, and it smothers the bacteria and clogs the works. Wipes do not break down either, flushable or not, and they are a leading cause of pump and line trouble.

Two habits help more than any additive sold in a jug. Spread laundry across the week instead of running six loads on Saturday, because a sudden flood of water pushes solids where they should not go and gives the system no time to recover. And go easy on the garbage disposal, which just sends more solids to a tank that then fills faster. If you want to protect the system, what you keep out of it matters more than anything you put in. When something does go wrong, the repair page covers the parts that fail.

What does the chlorinator do, and which tablets are safe to use?

On an aerobic system, the chlorinator is the last step before the treated water goes out to the spray field. After the system treats the water, the chlorinator disinfects it so the system is not spraying live bacteria across your yard where people and animals are. It is a simple tube that holds chlorine tablets, and the water passes over them on the way out. Simple, but it only works if there are tablets in it, which is one of the most common things found empty on a neglected system.

Here is the part to get right, because it is a genuine safety point. Use only the chlorine tablets made for septic and wastewater systems, which are calcium hypochlorite. Never drop in pool chlorine tablets. Pool tablets are almost always trichlor, a different chemical made for a different job, and they are not meant to sit in a septic chlorinator. Mixing chlorine chemistries can create dangerous gas, and the wrong tablet can damage the tube. The septic tablets and the pool tablets look similar enough that people grab the wrong bucket at the store, so it is worth reading the label. If you are not certain which kind is in your tube right now, do not guess: have the contractor confirm it on a maintenance visit. Keeping the chlorinator filled with the correct tablet is part of what a maintenance contract covers, and it is one of the cheapest things you can get right.

What is the spray field, and can I mow it or plant on it?

The spray field is where an aerobic system disposes of its treated and disinfected water. Instead of a buried drain field like a conventional tank uses, an aerobic system pumps the finished water through sprinkler heads and sprays it over an area of your yard, usually onto grass. If you have ever seen your sprinklers run at an odd hour when nobody turned them on, that was the system doing its job.

You can mow the spray field, and you should. Keeping the grass at a normal height helps the water soak in and keeps the mower deck from catching a sprinkler head you forgot was there. Grass is exactly the right cover for the area. What you should not do is treat it like ordinary yard. Do not plant a vegetable garden there, since you do not want treated wastewater on food crops. Do not plant trees or deep-rooted shrubs near the heads, the tank, or the lines, because roots go looking for water and find it. Do not park vehicles, build a shed, put up a trampoline, or stack firewood on the field or over the tank and its lids. Roots and compaction are two of the quiet, common causes of aerobic trouble, and both are avoidable. Keep the area open grass, keep the lids reachable, and you have done most of what the spray field asks of you.

I am buying a Hill Country property with a septic system. What should I check first?

Inspect the system before you close, and treat it as its own line item rather than something the general home inspector waves at. A septic system is a five figure thing to replace out here on rocky ground, so it deserves a real look. A transfer or real-estate inspection is inexpensive next to the cost of finding a dead system after the keys are yours. The inspection page covers what one includes.

The things to nail down: whether the system is aerobic or conventional, roughly how old it is, when it was last pumped, and, if it is aerobic, whether it has a current maintenance contract. That last one is not optional in Bandera County, where an aerobic system is legally required to be under maintenance, so a lapsed contract is both a red flag about how the place was cared for and something you will have to put right. Ask the county for the permit and the system records so you know what was installed and approved. Pay attention to access too, because a tank at the end of a long caliche drive with a buried lid is more expensive to service for the life of the property, and that is worth knowing going in. If the property is around Medina Lake, the Lakehills page covers the lakeside and weekend-load angle, and the Bandera and Medina pages cover the rest of the county.

What kills an aerobic system the fastest?

Neglect, paired with the wrong things going down the drain. An aerobic system needs three things working at once: air from the pump, chlorine in the tube, and a healthy population of bacteria. Take any one of them away for long enough and the treatment falls apart. The fastest path to a dead system is to stop looking at it. The maintenance lapses, the chlorinator runs dry, the air pump quits and nobody notices, the alarm beeps for a month until someone unplugs it, and the whole time the system is spraying water it is no longer treating.

Add the drain habits from the first question, the grease and the bleach and the wipes, and you speed the whole thing up. When an aerobic system finally fails, it does not fail quietly. It sprays poorly treated effluent across the yard, which is a health hazard for your family and any livestock, a code violation the county can act on, and the start of a repair or component replacement bill that dwarfs what the maintenance would have cost. The systems that fail early are almost always the ones nobody kept an eye on. The ones that last are boring: filled chlorinator, working air pump, three inspections a year, and reasonable drains. The cheap path really is the regular one, and the cost page lays out why.