The 11-year-old authority has finally finished determining who gets how much water and now is focusing efforts on protecting the water quality of the region's primary water supply. Although some consider any runoff from urban development to be a pollution concern, these rules focus on hazardous materials as a direct threat. The rules would attempt to eliminate some of the quickest pathways for aquifer pollution and, for the first time, require steps by facilities such as home improvement stores that stockpile large amounts of hazardous substances. "What we're doing with this is putting the responsibility where it should be rather than shifting it off on the public," said Susan Hughes, an authority board member from Bexar County. Hughes said that if a spill were to pollute the aquifer, not only could the owner and public agencies spend millions of dollars trying to clean it, but people in the region might have to live with the effects of polluted water for some time. Under the proposed rules, which are scheduled for public hearings this month, owners would have six months after passage to come into compliance with the new standards. The authority's boundaries cover all of Bexar, Uvalde and Medina counties and parts of Comal, Hays, Atascosa, Caldwell and Guadalupe counties, but state law allows the authority to extend the rules into a five-mile extraterritorial jurisdiction. That means the rules also would apply to the recharge and contributing zones in additional parts of Comal and Hays counties. The authority's rules for the first time would be applied to the recharge zone and contributing zone in part of Kinney County and to the contributing zone in parts of Edwards, Kendall and Real counties. State law exempts Bandera County from the extraterritorial jurisdiction. Since 2002, the authority's rules have banned any new petroleum storage tanks larger than 600 gallons on the recharge zone. And since 1996, San Antonio has required all tanks on the zone within its city limits to have triple containment, and it has banned any new ones. The rules are primarily aimed at ensuring that any leaks or spills on the environmentally sensitive area are contained. For example, for businesses that store large amounts of paints, pesticides or other chemicals, the rules require that along with the tank, can or other packaging the material comes in, it must be stored in a building capable of holding 1 1/2 times the volume of the stored material in an area that has a non-draining concrete basin. And if there's potential for a sprinkler system discharge in the storage area, the containment area must be able to hold 20 minutes of sprinkler flow. Most big-box stores, such as home improvement outlets, could come into compliance by simply adding a concrete lip an inch to an inch and a half high at the store entrance to create a basin capable of containing a spill of the store's hazardous contents and a 20-minute flow of its sprinkler system, the authority's consultants, Blanton & Associates Inc., told the board. Each business that stores regulated substances would have to prepare a spill prevention and response plan that must be reviewed and certified by a registered engineer. The plan would include a site map identifying all recharge features and the usual locations, quantities and types of regulated materials stored and steps to take to prevent or control spills. The estimated cost to come into compliance for a gas station on the contributing zone with three tanks that need to be replaced is $320,000, according to a study by the consultants. That cost would be $30,000 more on the recharge zone because of the triple containment needed. The company estimates that 132 of 247 regulated facilities will need modifications. Of the estimated $16.1 million cost to bring all facilities into compliance, $6.6 million would need to be spent in Bexar County, the consultants said. Almost $7.4 million of the costs would be borne by facilities in the extraterritorial jurisdiction and not presently regulated by the authority. Almost all the costs -- except $691,000 -- involve the upgrade of inadequate storage tanks, the consultants said. Most of the potentially impacted facilities are part of retail chains, such as regional or national gas sellers. "Our retail guys haven't really taken a look at how these proposed regulations might affect us," said Bill Day, spokesman for San Antonio-based Valero Energy Corp., which operates more than 5,000 retail gasoline stations. "I'm not even sure how many stores we have that would be in the affected area. We're always going to follow the regulations." A few of the regulated facilities are public agencies such as school districts, universities and utilities, but many of their tanks appear from records to already be in compliance with the proposed rules. Some think that the rules don't go far enough. Annalisa Peace, executive director of the Greater Edwards Aquifer Alliance, a coalition of 40 member groups that seek to protect the aquifer and the Hill Country, believes that the authority should take steps similar to those of the city of San Antonio and ban certain types of businesses on those sensitive areas. "GEAA endorses banning altogether commercial use and storage of hazardous substances on the recharge zone and other sensitive portions of the aquifer," Peace said. "Exceptions should be made only where these substances are necessary to protect public health and safety, and only with robust precautions to protect drinking water, streams and the aquifer." jneedham@express-news.net Key provisions of the EAA's proposed rules include: --Existing petroleum storage tanks on the recharge zone would have to be upgraded to triple containment; those on the contributing zone, the area that drains to the recharge zone, would have to be upgraded to double containment. --No unprotected outdoor storage of regulated substances in piles or containers would be allowed; they would have to be stored in an enclosure such as a tank or building. --All facilities that store more than 1,000 gallons or 10,000 pounds of regulated substances must notify the EAA of their existence and prepare a spill prevention and response plan. --The plan must incorporate methods for protecting aquifer recharge features from spills, including water used in the event of a fire. Efforts to protect the water