Gadjah Mada University drinking water supply system TOYAGAMA life cycle inventory

TOYAGAMA is the drinking water supply system (DWSS) of Gadjah Mada University. Acknowledging that its production operations have potential environmental and ecological impacts is essential. To ensure sustainable operations, comprehension of these impacts is necessary. The Life Cycle Assessment (LCA) has been reported to be an ideal method, but it has never been carried out, Life Cycle Inventory (LCI) is a vital preliminary step. Therefore, this study aims to construct an LCI database for the production of drinking water in TOYAGAMA DWSS, covering the process of raw water intake to treatment. This database could serve as a reference for future LCA studies involving similar technologies and as an overview of its potential impacts. The data collection methods included observation, literature review, and interviews. The collected data focus was carried out from September 26 to November 3, 2022. Organizing and processing were performed using Microsoft Excel and OpenLCA 2.0 Beta. The results showed that TOYAGAMA DWSS consisted of 15 unit processes and an additional 1 non-TOYAGAMA DWSS unit process was included in the LCI. Flows recapitulation showed that 15 environmental flows were involved. Evaluation using Life Cycle Impact Assessment (LCIA) method Environmental Footprint 3.0 indicated that the production of 1 m3 drinking water contributed to 12 of 28 potential impact categories. Based on the results, to produce 1 m3 of drinking water, 3.35293 MJ of electrical energy and 1.22723 m3 groundwater were required. Furthermore, plastic waste had the highest potential impact, with a total of 5 impacts.


Introduction
TOYAGAMA DWSS is the major drinking water supply system of Gadjah Mada University.This indicates that it is essential to comprehend the effect of this system to ensure its long-term sustainability.Its process of drinking water production involves the utilization of several vital components, including pumps, compressors, air dryers, Ultra Violet (UV) lamps, Ultrafiltration (UF) membranes, activated carbon filters, compressors, and sand filters [1].However, it is important to recognize that these production operations can have both environmental and ecological impacts, primarily due to the emissions generated.These emissions can manifest as greenhouse gases, solid waste, wastewater, and increased water usage.Once released into the environment, they will initiate a chain reaction that can cause harmful impacts on the environment and ecology.
Quantifying the environmental impacts of a product or service as a way to minimize the harmful impact of its emission can be done with Life Cycle Assessment (LCA).Furthermore, this technique can be used to assess the production effect of drinking water from the raw (cradle) phase to the processing (gate) phase.Several studies have reported the standardization of LCA [2], which enhances its reliability and comparability.Embracing this technique offers several benefits for product sustainability [3], enabling environmental-friendly product declaration [4], adjusting operational parameters [5], and providing data for decision and policy-making [6].Based on the findings, there are no studies on the use of LCA and Life Cycle Inventory (LCI) for TOYAGAMA DWSS.Therefore, this study aims to build an LCI database for drinking water production in TOYAGAMA DWSS, covering the process from raw water intake to treatment.The results are expected to serve as a reference for future LCA studies with similar technologies, and an overview of potential impacts associated with its production line.

Methods
Data collection methods included observation, literature review, and interviews.The data collected focused on raw water extraction to the treatment process, which was carried out from September 26 to November 3, 2022.Furthermore, collecting, organizing, and processing were performed using Microsoft Excel and OpenLCA 2.0 Beta.The collected data consisted of various types such as:  Flow Diagram for water treatment data  Emission & electricity production data by National Electric Company power plants from the official website [7]  Procedure data for lubrication maintenance of CR & SP pumps to calculate the impact during regular maintenance, collected from the Grundfos the official website [8][9]  Technical specifications of each component in water treatment [10]  Operational parameters such as volume of production and wastewater [10]  Duration and consumable materials portions, such as UV lamps, activated carbon filters, quartz sand filters, and UF membranes based on various sources [10] and  Life Cycle Impact Assessment (LCIA) methodology data, which was used to assess the potential impacts of emissions.The LCIA used was Environmental Footprint 3.0 (EF 3.0) [11].This method had the highest total characterization factor which was used to assess impacts at the midpoint level, and some references also used it to assess the impacts of microplastics [12].

Raw water intake and treatment unit
Observation results, interviews, and literature review [10] showed the involvement of raw water in the treatment unit process from September 26 to November 3, 2022, as shown in Figure 1.The processing line was divided into three segments as indicated in Figure 1, including:  Pre-Treatment Skid aimed to remove several solid particles and flocculated particles before entering UF Skid.It also prevented the UF membrane from being clogged quickly;  UF Skid had UF Module.It was a filter with ultrafiltration membrane technology capable of filtering particles within the range of 0.003 -0.2 μm.[13]; and  Distribution Skid segment: This was used to distribute drinking water to users.UV Light Module as the last treatment water component was used to reduce biological pollutants through the use of gamma rays.Apart from the three segments, there were two components, namely the compressor and air dryer.The compressor provided compressed air, while the air dryer dried the compressed air from the compressor to prevent corrosion.Furthermore, the two components were essential for operating pneumatic valves in the sand filter, activated carbon filter, and UF Module.

Product system and inventory analysis
Based on the conditions described in Figure 1, each input-output was recorded, and the mass balance was taken into account to derive the unit processes for each component.A series of unit processes were then arranged to form the product system for the production of Drinking Water, as shown in Figure 2.
The product system considered projections for the production of 1 m 3 of drinking water as the reference or independent variable, with the UV Module unit process being the focal point.
The product system for the production of drinking water was constructed with 15-unit processes from TOYAGAMA DWSS, based on the collected data, as well as a 1-unit process from non-TOYAGAMA DWSS.Furthermore, the 15 units from TOYAGAMA DWSS were located within TOYAGAMA DWSS area.The non-TOYAGAMA DWSS unit process was the Jawa-Madura-Bali Electric Generator, located outside the region.This unit supplied electrical energy to activate all the electronic equipment in the study region.
The summary of the flows showed that there were 15 environmental flows involved throughout the cradle-to-gate process, as shown in Table 1.To produce 1 m 3 of TOYAGAMA drinking water, 3.35293 MJ of electrical energy was required, along with the extraction of 1.22723 m3 of groundwater.The volume of water also considered the backwash or forward flush operations in the filters and draining in the product or feed tank.The production of 3.35293 MJ of electricity led to greenhouse gas emissions of 0.73765 kg in the Carbon Dioxide, Fossil flow.
The evaluation of the LCIA EF 3.0 showed that the production of 1 m 3 of TOYAGAMA drinking water had an impact on 12 out of 28 potential impact categories, as shown in Figure 3.The microplastic impact caused by the replacement of UF Modules was also calculated using a characterization factor based on the average of microplastics in the form of fibers, fragments, and foam [12].Figure 3 was  showing that water use is the most likely potential impact that will occur due to the TOYAGAMA production operation.
Discussion regarding the quantity and potential impacts of emission flows along the TOYAGAMA DWSS drinking water treatment process in Figure 4 could be explained as follows:  Potential impacts on the quantity of plastic waste emission due to the replacement of the ultrafiltration membrane in the UF Module had the highest effect. Aluminium was an emission flow caused by routine pump lubrication using Rocol Saphire Aqua-Sil & Un Lock anti-seize paste (Molykote P-74), and both products had Aluminium packaging.Furthermore, the results showed that its emission to the ground caused 4 potential impacts. Quartz sand replacement inside the sand filter and activated carbon filter have a potential impact due to their mate.rialbeing silicon dioxide  Glass lamps were assumed to be made of Silicon dioxide material, hence, they had the same quantity of potential impacts as the Silicon dioxide emission. Carbon dioxide fossil had 2 potential impacts and was emitted during the production of electrical energy used to operate electronic equipment. Coal was generated from the emission of activated carbon during the replacement of activated carbon filter media alongside water emission or extraction used in the production of TOYAGAMA drinking water each having 1 potential impact.Based on these conditions, the higher the chemical substances involved in engineering a product, the greater the emissions and impacts.This could be seen in the emission of polymer plastic flow due to the replacement of UF membranes, which had 5 potential impacts.
For further studies about the potential impacts of drinking water production, additional data regarding water quality from emissions were needed.The impact quantification, or impact assessment, was a stage that was carried out after the inventory analysis.In the Impact Assessment phase, each environmental flow was evaluated by applying it to the factor characterization of an LCIA methodology.Water quality  testing could be conducted to assess the presence of various substances carried by wastewater emissions into the environment during backwash, forward flush, and drainage processes.

Conclusion
The conclusion of this study was as follows: 1. Production of 1 m 3 TOYAGAMA drinking water required an electricity input of 3.35293 MJ, leading to greenhouse gas emissions of 0.73765 Kg carbon dioxide equivalent and extraction of 1.22723 m 3 groundwater.2. Analysis of environmental impacts revealed that among the 28 potential impact categories, 12 of them were identified as significant in the production of drinking water.3. Further analysis identified that the flow with the highest potential impact was plastic waste emission from ultrafiltration membranes replacement, and it contributed to 5 potential impact categories.

Figure 3 .
Figure 3.Total environmental flows contributing to specific potential impact chart.

Figure 4 .
Figure 4. Graph of quantity & potential impacts of emission flows.

Table 1 .
Summary table of flows involved in the TOYAGAMA DWSS water treatment unit product system that contribute to potential impacts based on the EF 3.0 method.