Des Moines, Iowa — Public hearings for proposed chloride and sulfate standards in Iowa were held this July. If approved, the proposed amendment to Iowa's Water Quality Standards, Chapter 61, would establish a numerical water quality standard for chloride and sulfate for the protection of aquatic life, and remove the Total Dissolved Solids (TDS) criteria and implementation approach that the state of Iowa has been using to test water toxicity in various rivers, streams and lakes across the state.
In 2004, the Iowa Department of Natural Resources moved forward with proposed chloride standards, but concerns were raised that it was not scientifically defensible to use in the state. Therefore, a state chloride standard was not approved, and instead, an interim strategy — TDS — was used as a water quality indicator.
There were concerns from environmental organizations that TDS standards were too lenient. Then in 2005, an environmental coalition of more than 70 groups, filed a law suit against the U.S. Environmental Protection Agency, stating that the agency approved Iowa state water standards that could threaten aquatic life in Iowa — a major concern being that the state's standards allowed for unacceptable chloride levels in discharge.
“When we tried to pass chloride criteria in 2004, we had a new criteria drafted for the chronic criteria side of it, one of the problems was the significant cost to treat it,” said Adam Schnieders, senior environmental specialist of the Iowa Department of Natural Resources. “The only way it could be done was reverse osmosis, then you have a brine reject waste stream and there is that environmental liability too. So a study was done with the Iowa Water Pollution Control Association and the DNR to figure out what types of levels of chloride and sulfate and constituents of TDS were sampled. The whole purpose for this was so when we do get a new criteria we would know the new compliance impact.”
The IDNR was also looking into new water treatment technologies that were being used in other areas of the country.
“From all the other states we looked at, we didn't see any new silver bullet type of treatment,” said Schnieders. “We looked at the Santa Clarita case in Calif., which is a well known story of chloride compliance. No one recognized a suitable treatment option for it. We [the state of Iowa] don't see a treatment option as cost effective at this time. That's not to say something could come along that is cost effective.”
In Santa Clarita, Calif., self-regenerating and automatic water softeners have been banned because of chloride levels in the Santa Clara River. In 2003, Santa Clarita Valley residents were prohibited from installing self-regenerating water softeners, including new and replacement units in their homes based on an ordinance, serving the waste water treatment and disposal needs of the Santa Clarita Valley.
Most recently, the Santa Clara River Chloride Reduction Ordinance of 2008 was approved, requiring removal of all residential automatic water softeners since they dump brine into water systems and treatment facilities can't remove brine, according to Preetie Ghuman, civil engineer at the Sanitation Districts of Los Angeles County.
In spite of the ordinance, a new waste-water treatment plant will be built in order to meet chloride standards.
Iowa proposal is unique
Since 2004, Iowa has been using TDS to measure toxicity levels in waters, and according to Schnieders, TDS came to be as a product of ancient rule making in the state in the 1970s and because the state did not have the chloride criteria that dealt with aquatic toxicity in its standards, it needed to be addressed.
“The interim toxicity testing approach uses a threshold level, so if TDS was over 1,000 you needed to do a toxicity test, and that wasn't working out very well,” explained Schnieders. “There was no way of knowing what levels were elevated based on the TDS, so that's why we went to a specific ion approach.”
Testing water toxicity by chloride and sulfate is successful because it is based on defensible scientific toxicity and incorporates site-specific water chemistry.
“We know that the Environmental Protection Agency in a way did not necessarily disagree with the TDS standard at the time since we had nothing else, we know they are on board with doing this proposal,” said Schnieders.
The EPA has a chloride criteria, created in 1988, which is part of the U.S. Clean Water Act. Currently, EPA does not have a sulfate criteria. The sulfate criteria being proposed in the amendment was developed in Illinois. Research in Illinois resulted in determining the effect of water hardness and chloride on sulfate toxicity.
“The number one thing unique about our proposal is that it recognizes the relationship of chloride toxicity to sulfate levels and hardness levels based on lab work done by Illinois National Survey, and work our office has done with the EPA research office in Duluth, to figure out that relationship and incorporate that into our standard,” said Schnieders.
The Water Quality Association along with other associations, organizations and individuals attended the public hearings this July.
“The WQA agreed with the science, obviously they have some concerns about the implementation, but seemed to be very optimistic about solutions,” said Schnieders.
According to David Loveday, director of government affairs and communications at WQA, the association is suggesting solutions for the state of Iowa, giving examples of what has been successfully done in other areas.
For example, according to a Pacific Water Quality Association report, a laundry mat in Southern California was updated with new 2-in. Hydrus valves and meters. Salt consumption dropped from 12,000 lbs. to 3,000 lbs. per month, with a 40% savings in water consumption.
However, there are some concerns from plumbing and HVAC professionals.
“If the end user can't use a softener in hard water areas there will be a mineral build up in the water heater on the electric coils or on the bottom of gas heaters,” said Gary TerWee, president of PHCC-Iowa. “The build-ups will also significantly reduce the life of the water heater, so it will affect energy efficiency.”
Possible compliance paths
There are different compliance paths that can be taken if the Water Quality Standards is amended with the new chloride and sulfate standards.
“The proposal is a conservative environmental protection approach with the ability to change a little bit, based on site/area specific conditions,” said Schnieders. “There is the ability to go back and check, so while looking at source reduction, they can also do a site specific limit calculation, so there are a lot of different compliance paths to go about and do this.”
If a town can't comply with the new chloride standards, it will need to find out where the source of the chloride is coming from, which could be water treatment plant backwash, home softeners or the finished water could be naturally soft and generally filled with chloride.
Once the town identifies where the chloride is coming from, through voluntary means, the town can try to reduce the source's chloride, said Schnieders, whether its literature educating folks not to use too much salt, or having folks update home softeners if they have old types.
According to TerWee, many areas would not need to change anything because there is enough water flow at the discharge of the waste water plants that with dilution it will not be an issue, but Northwest Iowa will be the hardest hit.
Northwest Iowa is an area that has harder water that needs to be treated with softeners, and the area is flatter with less water runoff, thus, less dilution, added TerWee. The watersheds originate in this area too, so there is minimal flow to dilute the discharge from the treatment plants, and if there is a dry period the only water in some of the streams is from the discharge from the treatment plants.
The proposed amendment will be added to Iowa's Water Quality Standards after it is approved by the EPA, which is expected to be March 2010. Anyone interested in commenting on the amendment can do so until Aug. 14, 2009 by e-mailing Adam Schnieders, IDNR, at [email protected].