NEMA termed the residents' accusations against it as baseless and aimed at tainting its image.
Kenneth Koreje, the Principal Water Quality and Pollution Control Officer at WRA, informed the court that after analysis of water samples that in certain areas there were high concentrations of oil and grease.
The damage was more in areas where the spill occurred, while in areas far from the spill site, concentration was either low or not present.
Dr Jefferson Kaloki Nthanga, a Veterinary Surgeon, said a post-mortem on the livestock revealed that the ruminal contents of the sheep smelled of oil.
The court noted that it was not in dispute that there was an oil spillage within the Thange River Basin on May 12, 2015, wherein a pipeline leak occurred at 256.9 Kilometres from Mombasa in Thange, Kibwezi, Makueni County.
The oil spillage contaminated the soil, air, river water, surface water, borehole water and negatively impacted animals, plants and human health.
"From the evidence tendered by the parties herein, it is clear that there was pollution of the environment in Thange River Basin, which included soil, surface and underground water, air and biota as a result of the oil spillage occasioned by KPC," read the judgment in part.
NEMA, the court noted, violated its obligations both to the environment and the residents.
"We have considered the evidence on record, including the reports from experts, which clearly show that the land within the Thange river basin was polluted to the extent that crops were not fit for human and livestock consumption."
"Further, the oil spillage affected the soil, crops, water, and livestock, thereby curtailing their livelihoods. We hence find that the 1st respondent (KPC) violated the petitioners' right to property," ruled the court.
The court noted that KPC, being the principal polluter, was aided by NEMA, which failed to continuously monitor and audit KPC's pipeline, besides failing to order immediate remediation after the oil spill.
NEMA, the court said, was a secondary polluter and apportioned liability at the ratio of 80: 20 between KPC and NEM, respectively.
The court said KPC and NEMA violated Constitutional obligations imposed upon them by the Constitution, adding that the discharge vouchers signed by the residents for crops and livestock are unconstitutional.
The court ordered KPC and NEMA to pay the residents general, punitive, and special damages.