Originally the Boroughs of Atlantic Highlands & Highlands had separate sewage collection systems and separate sewage treatment plants. These treatment plants provided primary treatment of sewage & the effluent from both plants was discharged directly into Sandy Hook Bay. In the early 1960's the Federal Government enacted a law prohibiting discharge of primary treated sewage. Therefore secondary treatment of the Boroughs sewage had to be made available.

The Monmouth County Master Sewerage Plan (MCMSP) was issued in 1966. This plan recommended that the Township of Middletown Sewerage Authority (TOMSA) be expanded to service Highlands & Atlantic Highlands. But because of delays and uncertainties in Middletown, Highlands and Atlantic Highlands requested an amendment to the plan removing them from TOMSA. In July of 1967 their request was granted. In 1968 the Atlantic Highlands/Highlands Regional Sewerage Authority (AHHRSA) was created. It consisted of three appointed members from each Borough. Its specific purpose was to provide secondary treatment of the sewage from both towns. In 1970 it was decided to build a secondary treatment plant to accomplish this. A service agreement was reached with Monmouth County Bayshore Outfall Authority (MCBOA) to dispose of their effluent in the Atlantic Ocean. In 1970 AHHRSA purchased a tract of waterfront property in Atlantic Highlands abutting Highlands as a site for the new plant. Design of the secondary treatment plant and the necessary pipelines was started.

The next two years was spent trying to obtain all the permits and funding. In 1970 the EPA recommended that NJDEP not fund the project at the site, both for aesthetic reasons and potential geologic risks. There was a fear that additional slumping, similar to what occurred in 1974 when MCBOA installed their 48 inch discharge line, might be experienced.

In 1978 the Environmental Protection Agency (EPA) and the AHHRSA jointly prepared an Environmental Impact Statement (EIS) and a 201 Facilities Plan. These plans proposed a design flow of 1.9 million gallons per day (MPG) by 2005 and reviewed some 34 alternative plans for providing the required secondary treatment of the Boroughs sewage. The most cost efficient solution was found to be an expanded TOMSA facility to provide treatment. However the NJDEP prohibited the expansion of TOMSA because of possible floodplain and wetland encroachments.

In March 1980, a modified EIS was submitted which reduced the design flow to 1.7 MGD. During EPA review, the Federal Government ruled that they would only fund for a 1.3 MPG facility. The Authority could build the larger facility, but they would be responsible for the additional cost. It was decided not to construct a facility larger than that which would be funded by grant money.

In 1982 the NJDEP withdrew their objection to the proposed TOMSA expansion and TOMSA and the AHHRSA proceeded to try to work out an agreement for the division of construction costs and for the subsequent operations. Meanwhile, the DEP continued to set deadlines for the completion of certain planning phases, always threatening that if these deadlines were not met the Authority's grant would be forfeited. The design documents were delivered on time, but the final service agreement between TOMSA and AHHRSA had not been worked out. The deadline was fast approaching. On September 23, 1983, the final day, an agreement was reached and the papers were hand-delivered to the DEP. In this agreement AHHRSA agreed to pay for 30.9% of the cost of the TOMSA expansion, based on design flow and the total capacity of the expanded facility. A payment of $1,500,000 was also to be made to purchase an equivalent share in the existing plant. Construction could finally begin. Operation of both facilities in their present form began in April of 1986.

The AHHRSA oversees the operation and maintenance of their two pumping stations, one in each town, and the several miles of force main that connects them and the main that transports the sewage to TOMSA for treatment. The treated effluent is then pumped to MCBOA to be discharged into the Atlantic Ocean. The AHHRSA has two customers, Atlantic Highlands and Highlands, who pay sewage fees based on the amount of sewage they send to the pumping stations. The flow, in gallons, becomes a percentage of the total flow that is sent to TOMSA. This percentage is then applied to the Authority's yearly budget and that amount is what each town is billed.

The Authority meets at 7 PM on the fourth Thursday of the month at Boro Hall in Atlantic Highlands and is open to the public.