Some of the steepest environmental penalties for water pollution in Georgia are being paid by taxpayers.

An analysis of state data by The Atlanta Journal-Constitution found that local agencies in metro Atlanta paid nearly $6 million in fines over the past dozen years for sewage spills and wastewater overflows into rivers and creeks, shifting local tax dollars into state coffers.

Municipal officials say new technology, better consumer education programs and the region’s growth slowdown have helped them decrease the leaks. The number of fines is down markedly since a peak in 2004.

But environmentalists question whether state fines are enough to stop a pollution threat to Georgia’s waterways, which often supply drinking water. Local governments police leaks and spills themselves, which they say is cause for concern.

Overflows and spills happen for several reasons — aging infrastructure, vandalism, cooking grease clogging pipes — but the result is the same: Some of Georgia’s most consistent water quality polluters are local authorities.

“You evolve from having a problem, trying to address the problem, then working with the state to reach a negotiated settlement,” said DeKalb County Watershed Management Director Joe Basista. It can be a complex process, he said, one in which it may be cheaper to simply pay the fines than improve a system.

But fall down on maintenance, Basista said, and systems may pay an even bigger price.

Four major metro Atlanta systems since 1998 each paid fines that totaled a half-million dollars or more; Fulton County alone paid more than $1.2 million, according to the analysis of a 10-county metro area.

East Point, a city of 33,700, paid more than $370,000 in fines — the fifth highest total and more than the $333,000 levied on the Clayton County Water Authority, which serves 250,000 people.

DeKalb County and the city of Atlanta are under federal mandates to improve wastewater systems, having paid hundreds of thousands of dollars in additional federal penalties for chronic problems and fixes.

In Atlanta’s well-publicized case, the data show state fines — totaling more than $630,000 — slowed markedly after it agreed to landmark federal consent decrees in 1998 and 1999 to eliminate sewage overflows and severely cut pollution in the Chattahoochee River.

DeKalb paid more than $980,000; under its new consent order, it faces a stipulated federal penalty of $500 a spill, Basista said.

State officials said the fines to counties and cities are some of the biggest they dole out. It makes sense: Metro systems are some of the biggest in the state. The individual instances are often not spectacular — compared, for example, to a record $1 million penalty imposed last year on a King America Finishing textile plant after a massive fish kill on the Ogeechee River in south Georgia.

Fines are levied by the Environmental Protection Division, a branch of the Georgia Department of Natural Resources. The division, which relies on local authorities to self-report problems, does not take action for every spill or overflow. It evaluates each event and may group them together. The number of reported spills often exceeds the number of fines.

Wastewater is defined as used water that includes substances such as human waste, food scraps, oils, soaps and chemicals — all washed down drains in homes and businesses every day. It also includes storm runoff, which washes over roads, lawns and rooftops picking up harmful substances such as antifreeze and lawn fertilizers.

Federal authorities say overflows threaten the public because raw sewage can have high concentrations of bacteria from fecal contamination, as well as disease-causing pathogens and viruses. These overflows can occur in backyards, city streets and directly into streams and rivers, caused by anything from pipe blockages to overwhelmed treatment plants.

“It’s not a pretty problem,” said Joe Cook, Upper Coosa Riverkeeper and executive director of the Coosa River Basin Initiative.

The spills and overflows noted in state records are accidents, not deliberate. Still, Cook and others want local authorities to do a better job of preventing them.

In 1998, the state DNR board asked for increased enforcement to protect the Chattahoochee and other waterways around metro Atlanta. That resulted in a zero tolerance strategy toward spills, causing water systems to chafe and ask for more flexibility.

In 2002, the state agreed to allow certain sewage systems to avoid fines when they spill no more than 30,000 gallons of raw sewage and face reduced fines for spills under 200,000 gallons. Systems must demonstrate they are working aggressively to prevent spills to qualify for the exemption.

Fulton is one of five systems currently in the program. Others are Cobb and Gwinnett counties, the Macon Water Authority and the city of Rome. Clayton plans to apply.

Local authorities said cooking grease and tree roots often cause the biggest pipe blockages. Vandalism plays a part, too; an example would be kids throwing debris down a sewer grate or open manhole. So do aging pipes and infrastructure, including wastewater treatment plants.

Time and money have not always been in ample supply to deal with those problems, authorities said, as communities over the past decade dealt first with the area’s population explosion and then a recession. But new technology, which these days include geo-mapping and cameras that snake through pipes to check for problems, allows quicker responses and better prevention.

Authorities also cautioned that each system’s issues differ depending on age, size and miles of pipe.

The system serving Cherokee County, for example, was mostly built in the past 25 years. Clayton has some sewer lines that date to the 1950s.

“You can’t afford to replace a thousand miles of sewer lines,” said Mike Thomas, general manager of the Clayton County Water Authority.

The authority spends about $2 million annually evaluating and replacing problem areas. Still, accidents happen: The state fined Clayton more than $18,000 in February and has proposed another $15,000 fine for raw sewage spills.

“We’re doing our best,” Thomas said. “We treat it very seriously. I know most of my counterparts are putting a big effort into this.”

Fulton, last fined in 2010, began a “root control” program in recent years, spokeswoman Jessica A. Corbitt-Dominguez said. In 2007, it started a public education program about the dangers of washing down kitchen drains grease, fats and oils. It’s also boosted inspection and cleaning programs, she said.

Still, critics said a policy that allows local officials to police themselves without firmer mandates is a concern. “It’s cheaper for them to constantly pay these fines than spend the money to upgrade their facilities,” said Hutton Brown, an attorney for GreenLaw, a legal organization that specializes in environmental issues.

Not so, state officials said. The fines, said EPD Assistant Director Jim Ussery, are meant to discourage systems from not complying with the rules.

He said they also are “meant to negate any financial benefit the violator may have realized by not paying the cost to comply.”