[Old building sewage system] Biogas leaks from the septic tank in the basement of the building and the sewage pump frequently burns out? Taipei commercial property electromechanical underground sewage pool maintenance and aeration system upgrade

Root analysis of biogas leakage and sewage tank odor in the basement of the old building

When you walk into many old commercial buildings, shopping malls or mixed residential and office buildings in the greater Taipei area, there is often a lingering pungent stench in the basement or parking lot. This smell is not only a severe olfactory pollution, but also contains corrosive and toxic "hydrogen sulfide (H2S)" and flammable "methane (CH4, biogas)". The root cause of odor and methane leakage is usually the lack of proper maintenance of the "underground sewage tanks and septic tanks" on the third or fourth floor underground for many years, or the aging and cracking of the tank's sealing cover. In a closed anoxic environment, organic matter in domestic sewage is decomposed by anaerobic bacteria to produce a large amount of acidic biogas. These gases will not only flow back into offices on the first floor or even high floors through drainage pipes, but will also combine with water vapor in the air to form dilute sulfuric acid, which will violently corrode weak wire troughs, iron pipes and electromechanical control boxes in the basement. It is an invisible killer in commercial property management.

Electromechanical protection and dual-circuit switching configuration of sewage pumps that are frequently burned due to debris

Underground sewage tanks must rely on "Sump Pumps" to pump wastewater up to the municipal sewer. However, sewage pumps in old buildings often burn out due to the following reasons, causing water in the basement to flood the computer room:
1. Due to the large number of tenants in commercial buildings, paper towels, rags, and plastic bags are often thrown into the toilet. After entering the sewage pool, these debris will become entangled in the impeller of the drainage pump, causing the motor to become stuck and overloaded, and the coil will overheat and burn out within a few minutes.
2. The heavy-weight float switch (Float Switch) that controls the opening and closing of the drainage pump is prone to losing its buoyancy and getting stuck in the "on" position when covered with oil and dirt for many years. This will cause the sewage pump to continue to "idle without water" after the pool water is drained, and the motor will quickly burn out due to lack of water flow to dissipate heat.
In order to solve this pain point, modern electromechanical engineering always adopts a configuration: install two mutually backup sewage pumps in the pool (a crushing sewage pump equipped with a serrated shearing blade, which can chop fiber debris). The control box uses PLC or alternating relay, which automatically starts pump A or pump B in turn every time the water level rises. When one of the pumps fails or the water level exceeds the warning line, the system automatically starts the other pump and sounds an alarm to ensure that the drainage system is not interrupted for 24 hours.

Underground sewage pool aeration mixing system and activated carbon filter upgrade method

To completely eradicate the stench in the basement, pumping water and fertilizer alone is not enough. The "aerobic aeration mixing and activated carbon filtration system" renovation method must be introduced:
* Lay a multi-hole stainless steel aeration pipe or an anti-clogging bubble diffuser (Diffuser) at the bottom of the underground sewage tank, and fresh air is continuously injected from the annular blower in the ground machine room. Convert anaerobic environment into "Aerobic Environment", inhibit anaerobic bacteria from producing hydrogen sulfide odorous gas, and prevent sludge from solidifying and depositing on the bottom of the tank through bubble stirring.
*Replace the maintenance manhole cover on the roof of the sewage pool with an airtight explosion-proof cover, and set up an independent exhaust pipe connected to the "Stainless Steel Activated Carbon Odor Filter (Carbon Odor Filter)". The high porosity physical adsorption capacity of activated carbon is used to completely filter out the trace amounts of hydrogen sulfide and volatile organic compounds spilled in the pool, and then discharged to the outdoors on the top floor of the building using an exhaust fan to ensure that the air in the basement is fresh and odor-free.

提升商办与住宅大楼环境品质以增加物业租售价值的关键

From the perspective of business assets and CapEx financial amortization, the return on mechanical and electrical renovation of the sewage and septic system in the basement of the old commercial office building is huge.
The stench in the basement and frequent sewage pump failures will directly lower the "visual and olfactory grade" of the building, causing the building's rent to be greatly reduced, and even being reported and fined by the Environmental Protection Bureau.将污水池升级为自动粉碎双泵系统、加装曝气搅拌与活性碳除臭，工程费用通常在 15 万至 30 万元之间。 This investment can eliminate the odor in the basement environment, avoid millions of maintenance fees caused by methane corrosion of mechanical and electrical lines, and improve tenants' satisfaction with property management, thus maintaining high rental yields. For real estate businessmen acquiring old commercial offices, solving this "invisible stench symptom" is a classic value-add operation technique to increase the property's assessed value at a low cost.

The Ministry of Economic Affairs' latest "Regulations on Consumer Electrical Equipment Installation" and the key points of electricity safety in old houses

Due to the popularity of high-power household appliances (such as air fryers, microwave ovens, dishwashers, instantaneous electric water heaters, and IH furnaces) in recent years, the Energy Administration of the Ministry of Economic Affairs has revised the "Regulations on Consumer Electrical Equipment Installation" many times to strictly require the diversion and protection mechanisms of residential electricity circuits. Statistics show that more than 30% of building fires in Taiwan are caused by electrical factors, among which "old wire insulation deteriorates and short circuits", "socket contacts are oxidized and loose, poor contact" and "non-fuse switch (NFB) overloaded and failed to trip" are the three main fatal causes.

Old apartments in Shuangbei that are more than 30 years old have a total original designed power capacity of only 30A to 40A, and several rooms often share the same 1.6mm or 2.0mm circuit. In the modern standard safety configuration, kitchen electrical cabinets, bathroom equipment, and air-conditioning and heating machines must all be equipped with 5.5mm² dedicated circuits (single circuit and single socket). It is recommended that the main switch box be upgraded to a busbar (Busbar) integrated distribution board, and the total amperage is increased to 75A or 100A (a qualified electrical appliance contractor needs to be entrusted to Taipower to review the additional power capacity).

Residential electricity self-test and regular inspection checklist

• Appearance and temperature of the socket: Touch the outer cover of the commonly used socket lightly with the back of your hand. If it feels lukewarm or if you find that the plastic socket is yellowed and charred, or the plug is loose and shaking after being plugged in, it means that the internal copper plate clamping force is exhausted or the contact resistance is too high, and you should immediately cut off the power and replace it.
• Regular testing of leakage circuit breakers (ELCB): For leakage circuit breakers in humid places such as balconies, bathrooms, and kitchen sinks, regulations require that the "TEST button" on the switch be pressed once every 1 to 3 months to confirm that it can automatically trip and cut off the power supply instantly.
• 严禁延长线串接与超载：Extension cords should be purchased with CNS certification and 2.0mm thick wire diameter products with automatic overload power-off protection. High-energy-consuming appliances should not share the same extension cord to ensure zero hidden dangers to life and property at home.