Africa and many Asian cities still employ the use of septic tanks to treat wastewater from the toilet. The use of septic tanks as an on-site wastewater treatment system is economically viable and affordable to the vast majority of developing nations. However, their utilization has been met with a dire challenge due to continuous corrosion and degradation of septic concrete surfaces. Concrete septic septic tanks are Constructed using conventional ordinary portland cement (OPC) and Portland pozzolana cement (PPC). However, OPC and PPC-based concrete Septic tanks are susceptible to biological, mechanical, and chemical degradation. Degradation of the concrete septic leads to their failure hence imposing tremendous environmental problems. The aftermath is the emergence of sanitation-related diseases. The wastewater from failing septic systems leads to contamination of the groundwater or the surface water resulting in the pollution of drinking water. Therefore, the need to explore other possibilities and potential construction materials to achieve sustainable sanitation is inevitable. The use of Limestone Calcined Clay Cement (LC3) in the construction of degradation-resistant concrete septic septic systems has not been well explored in Kenya. LC3 concrete is resistant to the deterioration effects of aggressive media such as acids, chlorides, and sulfates. Therefore, this research involved the performance of Limestone Calcined Clay Cement (LC3) as an alternative cement in the construction of concrete septic structures. The effects of biogenic sulfuric acid on simulated concrete septic systems made from (OPC) and (LC3) were investigated. Concrete cubes of OPC and LC3 measuring 150×150×150mm3 were cast and water cured for 28 days in two sets. One set of cubes was subjected to a biogenic biogenic sulfuric acid solution of pH2 for 30 days in repeated wet and dry (W-D) cycles. The second set acting as a positive control, was placed in pure water for 30 days. After 30 days of soaking in biogenic sulfuric acid solution and pure water, the cubes were subjected to different tests, which were compressive strength, sorptivity, and porosity. It was observed that after 28 days of curing, OPC cubes had slightly lower compressive strength of 34.4488 MM2 /KN than LC3 whose recorded strength was 32.351 MM2 /KN . However, LC3 concrete cubes are expected to have higher compressive strength than the OPC. Cubes curing time increases due to increased pozzolanic activity. Sulphuric acid attacks on hydrated cement products cause a decrease in compressive strength. The water absorption profile of LC3 cubes was lower (7.1808 kg ) as compared to OPC cubes (8.23446 kg). LC3 cubes had a high potential of resisting H2SO4 degradation as compared to OPC cubes. After 28 days of curing, OPC cubes had slightly higher compressive strength than LC3 mortars. However, As a result of increased pozzolanic activity of the clay pozzolana, the compressive strength of LC3 mortars is expected to improve significantly than OPC when curing in sulphuric acid. Water absorption was lower in LC3 than in OPC. Blended cement is less porous than OPC, according to this research. As a result, they are less susceptible to degradation as a result of strong media penetration .The resistance to biogenic sulfuric acid attack was stronger in LC3 than in OPC. This revealed that they might be used to make more durable constructions.Biogenic sulfuric acid attack on cement hydration products causes a decrease in compressive strength which was witness in OPC cement. From this work, it can be concluded that LC3 has a good performance profile in resisting deleterious materials. Therefore, further research is recommended to acertain its use in the construction of resilient and durable sanitary facilities such as septic tanks.