Approximately 40 county households in south Modesto which receive sewer service through the city of Ceres found themselves reaching for the aspirin after receiving a retroactive charge stemming from a billing issue as far back as three years.

Recently the city sent out notices to some homeowners living in the area south of the river and between Bystrum and Herndon roads, notifying them that they owed monthly service fees reaching back three years. In most cases the fatter bills were produced after the city discovered that some second units on a single lot were being serviced but not billed. City Manager Toby Wells said that the discovery was made from satellite photos. About 40 residences are affected. They were notified that the city is offering payment plans for the bills, which are due April 1.

State law allows cities to collect underbilled service for a maximum of three years but Wells said some second units escaped billing for decades.

The neighborhoods outside of the city limits began receiving service about 10 years ago. Since that time the city did not have the benefit of knowing about second units because it doesn't provide water service. Most of those units were garages converted to living space without a building permit. Audits through satellite photos allowed the city to flag the situation.

Wells said the city cannot disregard the shortages at the expense of other residents who pay their fair share of impacts to the city sewer system.

Rebecca Harrington, who sits as an elected member and chair of the South Modesto Municipal Advisory Council, addressed the City Council on Monday and said her own household is impacted. She and a son reside with her 87-year-old mother, Emily Ortega, who got a city bill for $1,842.72. The extra charge stems from the city not realizing for years that a second unit on the property was getting service. Another son of Harrington's lives in the granny flat.

"We had no prior communication that there was a problem," said Harrington. "This is an exorbitant fee ... we're being made to feel as if we did something wrong."

Harrington believes residents should pay the extra fee going forward but not the retroactive bill, claiming they were unaware of the city's mistake.

Mayor Chris Vierra said he feels for the residents but cannot ask other residents to pay for the deficit.

Harrington didn't get anyone on the council to waive the debt but Bret Durossette suggested waiving the interest charges on those who need to make payments. The council agreed that, as a matter of policy, it would extend the same policy to others with second units who are found owing on under-billing.

The council said it would extend repayment to a five-year period.