Characterization of SPPG Wastewater for Treatment Planning in Sleman Regency

Abstract

The Free Nutritious Meal Program generates kitchen wastewater containing organic matter, suspended solids, oil and grease, and microorganisms. This study characterized wastewater from 10 SPPG facilities across 10 sub-districts in Sleman Regency based on BOD, COD, TSS, oil and grease, and total coliform, and compared the results with applicable standards under Minister of Environment and Forestry Regulation No. 11 of 2025. Results showed substantial variation, with TSS of 121–7,340 mg/L, BOD 91–1,445 mg/L, COD 829–8,078 mg/L, oil and grease <0.2–168.4 mg/L, and total coliform exceeding 16 × 10⁸ MPN/100 mL at most locations. Most parameters exceeded the applicable standards. Higher pollutant concentrations tended to occur at facilities with higher production volumes and fried-food menus, although these relationships were based on observed patterns rather than statistical testing. The findings provide baseline wastewater characteristics for SPPGs in Sleman Regency and support treatment planning, particularly the use of grease traps as pretreatment before biological processes. The study is limited by a single sampling event at each facility.