OAKLAND — The city is suing its residential recycling contractor on allegations that it’s ripping off the owners of multi-family dwellings by overcharging for the service of pushing heavy recycling carts to the curb.

The city says California Waste Solutions is charging multi-family property owners $152.68 a month — and in some cases up to $776.16 — for CWS workers to move recycling carts to the curb for collection. The city claims that under its negotiated contract with CWS, that service is supposed to cost $27.85 a month for both single- and multi-family property owners.

California Waste Solutions founder David Duong did not return a request for comment Monday. CWS is a small, local company that has contracts with the cities of Oakland and San Jose.

“CWS must be prevented from taking advantage of a mere draftsman’s error in the rate table to gain an unjust, undeserved and oppressive windfall that could amount to tens of millions of dollars over the life of the contract,” the lawsuit filed last month by Oakland City Attorney Barbara Parker’s office reads.

In a message to Oaklanders, Parker said the city “was forced to file this lawsuit because CWS has refused to budge from its clearly unreasonable position.” The city fears the impact that exorbitant recycling rates will have on its troubled affordable housing market.

The lawsuit asks the court to force CWS to stop overcharging and to reopen the city’s recycling contract to include a missing line item for “premium backyard service” for recycling cart movement at the $27.85-a-month rate. The city alleges that CWS had misinterpreted the current contact to reserve the right to charge multi-family property owners up to $776.13 a month for pushing heavy and large recycling bins to the curb to be emptied into CWS trucks.

“Over the life of the 10-year contract, these overcharges amount to tens of millions of dollars of unjustified excessive charges to Oaklanders, depriving them of funds they otherwise could use to maintain properties and exacerbating Oakland’s ongoing rent and housing crisis by leading to rent increases,” Parker said.

The lawsuit alleges potential excess charges for multi-family properties of $1,832.16 to $9,313.56 per year for one cart to be pushed 100 or more feet, a service that costs a single-family homeowner $334.20 a year.

In another Alameda County Superior Court lawsuit filed last year, three owners of multi-family properties in Oakland are suing the city over recycling and garbage-collection rates by CWS and the city’s garbage contractor, Waste Management. The landlords allege they’ve been subjected to exorbitant and illegal rates far beyond what was promised at city meetings on the city’s $1.5 billion Zero Waste garbage and recycling contract.