# Critical Study Quality Management for the Anti-Seepage System in Macau's Landfill Area
## 1 Introduction
#### Introduction to the Background and Importance of the Macau Landfill Anti-Seepage
Additionally, sea mud is a specialized type of waste that typically requires specific handling and management. If a large amount of sea mud is dumped into the landfill, additional anti-seepage measures may be necessary to ensure there is no contamination of the surrounding soil and groundwater (Figure 3). From the data, it can be observed that there is significant fluctuation in the total construction waste volume across different years, with notable peaks in 2014, 2015, and 2020. However, overall, the fluctuations are quite apparent. The handling of construction waste may impact the landfill's anti-seepage system, particularly concerning the types and quantities of waste. To ensure environmental protection and the effectiveness of the anti-seepage system, close monitoring and management of the construction waste disposal process may be required, along with the implementation of appropriate measures to address potential issues (Table 1). Figure 3: Source: Macau Environmental Protection Bureau/Total construction waste. According to the data in Table 1, we can analyze several issues:  
* Fluctuation in total construction waste: From 2010 to 2022, there is an overall upward trend in total construction waste. Particularly, a sharp increase is observed between 2013 and 2015, suggesting a possible surge in construction activities or demolitions during that period. However, after 2016, the total amount decreases, with a peak again in 2020. This fluctuation may be related to economic activities in the construction industry, policy changes, or other external factors, such as natural disasters;
* Changes in proportions of different types of construction waste: The proportions of different types of construction waste (inert dismantled materials, sea mud, mixed construction waste, slag) vary in the total amount and fluctuate over time. For instance, the proportion of inert dismantled materials in total construction waste is constantly changing, reflecting potential shifts in construction material usage and methods. Similarly, the quantities of sea mud and mixed construction waste show significant differences in different years;
* Dramatic fluctuation in sea mud quantity: The quantity of sea mud peaks in 2015 and rapidly declines afterward. This may be related to specific construction projects or environmental policies;
* Yearly reduction in mixed construction waste: Starting from 2016, the quantity of mixed construction waste decreases annually, indicating an improvement in the efficiency of construction waste classification and processing;
* Stable trend in slag production: Compared to other types of construction waste, slag production remains relatively stable with minimal fluctuations. These data indicate significant variations in both the quantity and types of construction waste over different years, likely influenced by factors such as construction industry activities, policy adjustments, technological advancements, and increasing environmental awareness. These changes also suggest the need for further strategies in construction waste management and recycling. Based on the data in Table 1, we can propose some relevant theories and considerations for quality management of landfill construction and impermeable systems:  
* Building waste types and material selection for landfills: The data show variations in the quantity of different types of construction waste, impacting the selection of materials for landfills.