stract In accordance with law, the 88,000 cesspools identified in Hawaii must be replaced with another wastewater treatment system by the year 2050. To meet these standards, the Eljen Corporation is attempting to implement their Geotextile Sand Filter, or GSF system, in the islands of Hawaii. However, due to the location of the islands, the transportation of ASTM C-33 presents both economic and environmental challenges. The ME 22 team is tasked with looking for alternate aggregates that meet the standards of ASTM C-33: biological oxygen demand (BOD) of ≤10 𝑚𝑔/𝐿 , a desired total suspended solids (TSS) value of ≤10 𝑚𝑔/𝐿 , less than 10% passing a #100 sieve, less than 5% passing a #200 sieve, and a percolation rate of 0.033±0.003 in/s. Possible materials have been identified, such as fine crushed glass, crushed oyster shells, coconut fiber, and volcanic rock. Current results suggest all materials will move on to BOD and TSS testing, besides coconut fiber, which had 13.59% passing a #100 sieve, omitting it from further testing. The highest performing material through sieve testing is crushed oyster shells, with less than 3% passing both the #100 and #200 sieves. From these results, the 2025 team will prioritize BOD and TSS testing, as well as exploring combinations of identified materials, in hopes of determining a suitable alternative for ASTM C-33.