Septic tank maintenance

December, 2011:

How to Get Rid of Septic Tank Bio-Mat Buildup

Biomat is that dark substance that resembles tar which forms and accumulates at the sides and at the bottom of the trenches situated in the drainfield or drainage pit area. The bio-mat is basically undigested waste that is left over during the decomposition process involving anaerobic bacteria. The anaerobic bacteria, found throughout the entire system, feed on the wastewater because of its rich organic matter. In stressed systems, the biomat develops into a thicker goo that decreases the flow rate of the soil that surrounds the septic drainfield or drainage areas. A small amount of bio-mat is healthy for a system since it acts as a pathogenic filter when the wastewater goes through it. This means that the biomat gets rid of the disease-causing microorganisms that the wastewater has, making it safe for the environment when it reaches the groundwater. 

Beyond the premises of the biomat are where the anaerobic bacteria reside. These bacteria consume the biomat to prevent it from becoming too thick where it is maintained so that the wastewater could still pass through to the subsurface soils. When there is flooding or system abuse, the bacteria colonies begin to die down. This leaves the biomat free to become thicker and thicker because smaller numbers of bacteria cannot completely digest the waste properly. The excessive thickness of the biomat and the formation of sulfides will cause the drainage to be clogged and eventually stop the wastewater flow. A waterproof barrier will form courtesy of the excessive biomat accumulation and the wastewater absorption comes to a screeching halt. 

Where does biomat come from? This tar-like substance is from the solid wastes that settle in the septic trenches.  How does this happen? Well, you know the expert way households dump harsh chemicals into their drains, right? These chemicals kill the naturally-occurring bacterial population in the septic tank. The outcome is, of course, the inefficient digestion of the solid wastes. When the septic tank is not pumped out or heavily maintained according to schedule, the solids spill out into the drainfield. Here, the organic waste material builds up and coagulates, allowing thick biomat to form. This very thick substance will eventually clog the entire drainfield, causing the contaminated and untreated wastewater to the drainfield surface. Evidence of such failure usually results in poor drainage, backups, odors and so on. Septic bio-mat clogging can be a major headache but fortunately there are many techniques and methods to help improve digestion rates, thereby lessoning bio-mat buildup.

One way is to excavate your drain field and septic tank and completely replace the entire system. Obviously, this is usually the last resort since this replacement is normally very, very costly. The preferred method to restoration is to shock the septic system with a very high concentration of good bacteria. The good bacteria are introduced into the septic system via an additive. These additional bacterial colonies will aid in bringing back the normalcy in the digestion of the biomat that is throughout the drainage areas and piping. As with any mass of decomposing matter, additional bacteria will offset most toxic chemical damage caused by household cleaners and detergents. The amount of bacteria supplement will coincide with the amount of “abuse” your system is experiencing and this figure is usually tied to the current capacity of your home or building. 

                As a preventative, you can help prevent the build-up of biomat by not using water excessively, not dumping solid wastes into your toilets or drains, and not running your vehicles on top of the drainfield. Excessive use of water can make the sediments and gunk all stirred up. As a result, the solid wastes get swept  towards the drainfield, allowing biomat to flourish. Regular monthly maintenance will help assure that bio-mat does not develop to a point where blockage becomes an issue. In healthy systems, adding a commercial strength bacteria additive will supplement the natural colonies to help decrease the effect of general cleaners. Keep in mind that no additive can combat the ongoing damage caused by highly toxic chemicals such as ethers and those comprised of highly anti bacterial components. 

                Biomat can only be a problem when not kept in check. Having your system inspected every 2 to 3 years will help you understand the systems current condition and allow you to plan for use changes if needed. While most maintained systems rarely experience heavily compacted bio-mat, inspections are critical so as to verify that the structure of the system is still in operating order. While there exists dozens of advanced methods to bio-mat reduction or depletion, the regular use of bacteria additives along with a conscious effort to help keep the existing bacteria healthy is your first step to getting rid of and preventing bio-mat.