Manteca — after completing several tweaks to the city’s wastewater treatment plant — is expected to have enough remaining capacity to accommodate between 3,000 to 4,000 more housing units.

That would-be enough to sustain roughly six years of the current housing growth rate of 600 to 700 units being built yearly.

Public Works Director Carl Brown confirmed there is roughly “six to seven years of capacity” left in the current treatment plant configuration.

The plant was designed to handle a flow of 9.23 million gallons of wastewater daily.

That capacity has been lessened over the years by state-mandated changes in the wastewater treatment process.

Solid waste loading issues, however, have effectively lowered the adjusted capacity even more.

The council 13 months ago authorized  spending $508,057 for plans and specifications for seven projects designed to improve the process so the plant can end up functioning near its adjusted design capacity of processing 8.5 million gallons of water per day.

The plant was originally designed for 9.23 million gallons a day.

Staff in October 2023 when the expenditures were authorized, said the daily flow was between 7.3 million and 7.5 million gallons a day. The increased percentage of solids being processed due to water conservation measures is pushing the plant’s operational abilities  closer to where it would be capped at 8.5 million gallons a day.

Meanwhile, the city is working on a fourth phase expansion project that is being timed to hopefully go online before capacity runs out.

The existing plant was designed to allow a seamless increase in capacity.

But as city leaders learned the hard way 25 years ago, shifting state water quality regulations can pop up in the middle of an expansion project to create potential delays.

It is against that backdrop that development  agreements — essentially contracts between developers that provide the city with additional amenities and infrastructure beyond what is minimally required in exchange for sewer allocation certainty in future years — are becoming a must.

That’s because builders in order to secure expensive upfront financing for major site work and infrastructure must prove to lenders they have the ability to build out the project.

The city’s growth rules as outlined in Ordinance 800 require a twice annual review of sewer capacity to determine if there is capacity left to award to those endeavors not covered by development agreements.

Allocating sewer allocations over a number of years in exchange for additional concessions to the city was a solution developers came up with in 1998.

They feared that the 13 active builders in Manteca at the time would end up suing each other if some did not secure allocations during the twice annual assessment and review of sewer capacity.

That paid off for the city in excess of $30 million in “bonus bucks” that were essentially unrestricted development agreement fees that the city could spent as they saw fit.

The money helped pay for a number of things such as completing the financing of the Union Road fire station, traffic signals for the Tidewater Bikeway, and lighted soccer fields to name a few. The bulk — $11.7 million — went to plug revenue shortfalls leading up to — and during — the Great Recession to cover day-to-day municipal services.

Critics point out the use of that money avoided the city from asking citizens for additional taxes or else cutback services.

 Some argue that the philosophy of avoiding asking for tax increases to prevent service level from deteriorating or improving is what is now happening given police staffing, as an example, is still less than the budgeted level in 2008.

This time around, development agreements in some cases contain unrestricted fees the council can spend without strings.

But for the most part they involve concessions such as requiring all homes in a subdivision to be part of a perpetual community facilities district to finance additional police and fire personnel as well as maintenance of streets and parks within a new neighborhood, purchase new fire engines and garbage trucks to service growth, and to pick up tabs for off-site infrastructure needs such as widening arterials that aren’t directly tied to a project’s impacts.

The treatment plant capacity expansion will be funded using growth fees already collected for that purpose as well as growth fees yet to be collected.

To contact Dennis Wyatt, email dwyatt@mantecabulletin.com