Management of Produced Water from Oil and Gas Operations in Bayelsa State: Treatment Technologies and Regulatory Compliance

Produced water management in Bayelsa State, South South Nigeria, remains a persistent environmental governance challenge, with large daily volumes of highly saline and hydrocarbon-contaminated brine requiring treatment before discharge or reinjection. This study examines the treatment technologies currently deployed across 12 flow stations and terminal facilities in Bayelsa State and assesses their performance against the Department of Petroleum Resources effluent discharge limits. Primary data were collected through facility inspections, treatment system performance records, and operator interviews. Technologies in service included plate-pack separators, hydrocyclones, induced gas flotation, walnut shell filters, and electrocoagulation at select facilities. Compliance with the DPR oil-in-water discharge limit of 10 mg/L was achieved in 58% of inspected facilities during normal operations, declining to 31% during maintenance cycles. Produced water chemical oxygen demand and total dissolved solids consistently exceeded NESREA guideline values at all facilities. The study identifies the absence of mandatory sulphate and conductivity monitoring, inadequate solids handling infrastructure, and insufficient secondary treatment capacity as systemic gaps. A tiered compliance road map is recommended, incorporating minimum performance standards for secondary treatment and mandatory beneficial reuse targets for produced water in agricultural irrigation. Keywords: produced water, treatment technologies, DPR compliance, Bayelsa State, oil and gas