Hawaiʻi is home to more than 83,000 cesspools, releasing roughly 52 million gallons of untreated wastewater into the ground each day. This ongoing pollution jeopardizes drinking water quality, damages coral reefs, and poses serious risks to public health. In response, the state has enacted Act 125, requiring all cesspools to be upgraded or replaced by 2050 to safeguard Hawaiʻi’s environment and communities.

Under Act 125, all cesspools must be upgraded or replaced by 2050. Failure to comply could result in penalties, enforcement actions, or restrictions on property transactions.

Act 125 requires all cesspools statewide to be upgraded, regardless of location or size.

1. Your cesspool has failed or overflowed

2. You need to pump your cesspool more than 2 times a year

3. Improvements that require a building permit

The cost of converting a cesspool to a compliant wastewater system or for a new home, typically ranges from $25,000 to $50,000, depending on the specific system requirements and property conditions and sometimes more.

The appropriate wastewater system is determined by site-specific conditions, property layout, and regulatory requirements. Available options may include septic systems, aerobic treatment units, or other approved solutions. As part of the application process, a licensed engineer will evaluate your property and provide guidance on the most suitable system for compliance and efficiency.

Permits with the state of Hawaii department of health are required for system design and installation. When complexities such as space limitations, proximity to a drinking well or poor soil drainage come into play, additional applications (variance) maybe required.

The project timeline varies and generally includes system design, permitting, installation, and final approvals. Homeowners can help expedite the process by providing essential documents such as floor plans, property details, and cesspool information (if available), as well as coordinating with the engineer to complete soil percolation testing. The overall timing is influenced by the duration of the regulatory approval process and the availability of specialized contractors qualified to install wastewater systems. Full completion of a system may take anywhere from 30 – 90 days from permitting to final installation.

In Hawaiʻi, properties located within the No Pass Zone face stricter wastewater requirements due to their proximity to drinking water aquifers and groundwater resources. Defer to your engineer for proper determination of your system requirements.

This process requires the system design by a professional engineer, obtaining the authorization to construct from the state, site preparation and construction, as well as inspections and final approvals to ensure compliance with state regulations.