By: Kresensia Risna Efrieno.

Hearing the word ‘sewage' may bring negative assumptions and even antipathy, but in the reality, human life cannot be separated from waste. The Big Indonesian Dictionary defines waste as production residue, materials that have no value or value for ordinary or primary purposes in manufacturing or use, damaged or defective goods in the production process. There are several kinds of waste, from liquid, solid, and gas. The unwell-managed waste will cause disturbance or pollution. Ignoring pollution will damage the earth as a habitat for humans and other creatures into an uninhabitable place. The pollution problems range from garbage, air pollution, and water pollution. The waste problems can be managed with the 3R concept (reduce, reuse and recycle), reduce items that easily become waste, reuse, and recycle. Air pollution can be minimized by planting trees that produce oxygen, also the regulations to limit air pollution. Then, what about water that is polluted due to liquid waste, including domestic liquid waste, such as water used for washing, bathing, septic tanks, and household activities?

Stube HEMAT Yogyakarta with students are looking for answers how to treat domestic wastewater by holding exposure or field study at the Center for Wastewater and Urban Drinking Water Infrastructure Management (PIALAM) in Sewon, Bantul, Yogyakarta Special Region (Thursday, 11/11/2021). In the first part, the students received an explanation from the head of the Operations and Maintenance Section, Sudarno, that Balai PIALAM is responsible for organizing the network management and residential wastewater management system to improve centralized wastewater system services and management of drinking water network systems across regencies/municipal as well as sustainable supervision of drinking water services to regencies/municipal. He also explained the services at Balai PIALAM for Wastewater Treatment Plants (IPAL), Fecal Waste Treatment Plants (IPLT), and how the waste treatment process is carried out in three regencies/municipal, namely Yogyakarta, Sleman, and Bantul. There are two ways to distribute it to the waste treatment site, namely domestic liquid waste flowing from pipes connected to homes and processing sewage sludge which is transported using special trucks.

In the second part, the students with Heni, one of the operational staff observed the domestic wastewater treatment process, where waste flows from the inlet pipe to the pre-treatment which consists of coarse filtration, lift pump, grit chamber, and fine filter in which waste filtered and pumped to the Grit Chamber or sand deposition and through fine filtration. After that, the waste is distributed into aerobic and anaerobic settling ponds. The silt from the pond is transported to a drying pool, while the water enters the maturation pond and is added with a water purifier before being distributed into the river. Interestingly, fish is used as an indicator of the feasibility of treated water, if the fish dies it means that the exposure of waste is still strong and it applies to the opposite condition.

The fecal sewage treatment process is separated between solid waste and liquid waste using a Huber Sludge Acceptance Plant (SAP) pump. From here the waste will be sent to the waste collection point, and the liquid waste is channeled to the Sludge Separator Equipment (APLT). The sludge will be channeled into a holding tank while the wastewater will receive coagulation and flocculation treatments to reduce odors, bind sludge and purify water, including removing bacteria. From this result, it will be seen whether the water has been at the safe level or not. If not, then the process is repeated, and if it is considered safe, the water will be channeled to the IPAL installation.

The heavy rain during the activity did not dampen the enthusiasm of the exposure participants to explore every corner of PIALAM, but some students admitted that they could not persist being in that location because they were not used to the very strong smell of sewage. Through the exposure of the Water Security program, Stube HEMAT Yogyakarta brings students closer to the reality of waste that threatens the existence of water and presents new experiences and reflections, as well as raises awareness of the importance of water to emerge ideas that they can do something to minimize waste, protect water and the environment.