Camden-based New Jersey American Water signed an agreement Thursday to acquire the wastewater assets of the Township of Long Hill for $12.7 million.

The municipally owned sewer system serves about 2,800 customers, most of whom already receive water service from New Jersey American Water, according to the company.

The agreement follows voters approving the sale of the system to American Water at a referendum in November 2019. American Water spokeswoman Denise Venuti Free expects the purchase to be approved by the New Jersey Board of Public Utilities in summer 2020.

As part of the acquisition agreement, New Jersey American Water says it will invest more than $13 million in critical sewer system improvements in the next five years, while freezing current sewer rates for residents for two years and increasing rates no more than 3 percent annually for the next three years.

New Jersey American Water says these improvements include pump station upgrades, sewer main lining and replacements to reduce the infiltration of storm water, and treatment plant upgrades to reduce and eliminate the release of partially treated wastewater during heavy rain.

The company will coordinate sewer and water pipeline replacements with Long Hill’s road paving schedule to minimize disruption.