minutes

South Bay Irrigation District

January 17, 2005

The Board of Directors of South Bay Irrigation District held a regular meeting on Monday, January 17, 2005, at the Sweetwater Authority Administrative Office, 505 Garrett Avenue, Chula Vista, California. President Welsh called the meeting to order at 3:30 p.m.

ROLL CALL

Directors Present: Alkire, Doud, Pocklington, Salas, and Welsh.
Directors Absent: None.
Others Present: General Manager Dennis Bostad, Operations Manager Mark Rogers, Legal Counsel Peggy Strand, and Board Secretary Marisa Farpón.

PLEDGE OF ALLEGIANCE TO THE FLAG
Director Doud conducted the pledge of allegiance to the flag.

OPPORTUNITY FOR PUBLIC COMMENT (Government Code Section (54954.3)
There was no public present for comment.

PRESIDENT'S PRESENTATION
There was no presentation.

ACTION AGENDA

ITEMS TO BE ADDED, WITHDRAWN OR REORDERED TO THE AGENDA
There were none.

PRESENTATION BY DON THOMSON, DIRECTOR OF WATER QUALITY OF SWEETWATER AUTHORITY
Chlorine Dioxide: Silver Bullet

Operations Manager Rogers introduced Don Thomson, Director of Water Quality of Sweetwater Authority, who would talk about a relatively new water treatment at the Perdue Plant, Chlorine Dioxide.

Mr. Thomson said that Chlorine Dioxide is a nice cure for Trihalomethanes (THM's), which are formed in the treatment process. THM's are disinfection byproducts that are formed in the treatment process when we add chemicals, chlorine in this case, for disinfection. The intention is to regulate some carcinogen compounds and one of them is THM. Recent research shows that there are other problems besides THM being a carcinogen, and one of them is that it affects pregnant women in the third trimester.

Since 1979, the Maximum Contaminant Limit (MCL) is 100 parts per billion based on a system wide-running average (RAA). This means that every quarter we take samples from the system, we average the samples and the resulting figure for each quarter, and that becomes the annual average.

Mr. Thomson said that as of November 1998, the Phase I of the Disinfection Biproducts Rule lowered the standard to 80 parts per billion (ppb) for THM's and to 60 ppb for HAA5, still based on a system-wide, running annual average. A new component was added under Phase I called Enhanced Coagulation. As a requirement of the rule, we tried to remove the organic compounds or carbons, called precursors, by adding several chemicals to try and coagulate it and get it out of the system before the chlorine is added.

Phase 2, which is where we have to be in 2011, keeps the 80/60 levels and also keeps the Enhanced Coagulation. The change is that instead of being a system-wide average, now it is measured by location. Every individual sample point has to be less than the MCL. The sample points selected will be the worst-case sample points, which adds to the difficulty.

Mr. Thomson then displayed a graphic depicting the running annual average for the system after the Perdue Plant expansion. He said that Sweetwater Authority had been in violation of the MCL since about 1978, before the expansion of the plant. After the expansion, the MCL was brought down and has gone up a few times and only during the periods of heavy runoff. Mr. Thomson then showed the running annual average of the "I" Street and Woodlawn sample point in Chula Vista, which is one of the worse cases because the water is in contact with the chlorine for quite a while.

Mr. Thomson said that, in a search for solutions, Water Quality staff has been doing quite extensive testing. For a year we tested for ozone at the treatment plant. Ozone is very effective in keeping down the THMs. Unfortunately, the bromide in our water was high, and ozone reacts with bromide producing bromate, which is a regulated compound considered a disinfection byproduct at very low numbers. A full-scale test of enhanced coagulation was performed. To do this, we were taking triple or four times what is normally considered the dose of coagulants used for turbidity and adding it to the water trying to coagulate out the TOC/DOC. Because our basins and filters were designed way before any of these rules, the immediate effect was the efficiency going way down. All these chemicals were not being removed out the sedimentation basins and the filters had to remove the rest. The filters were clogged and we were washing more often and losing much more water. Basically, he added, we are trying to find a silver bullet to kill one monster, and we are creating others.

Water Quality staff decided to test Chlorine Dioxide, not so much to solve the THM problem but because we were having a problem with taste and odor, as well as manganese from using potassium permanganate. Chlorine dioxide was considered as a replacement for potassium permanganate. We were hesitant to do it because we are the first agency in the state of California to test Chlorine Dioxide as a primary disinfectant.

The reason it worked so well is because the chemistry of Chlorine Dioxide has a salt sodium chloride that reacts with chlorine. There is no free chlorine, and free chlorine was once causing problems. The result was that THM's went down to ten parts per billion as compared to the required eighty parts per billion. Mr. Thomson displayed a slide that showed the current THM levels at the I Street and Woodland sample point, where the levels have been consistently low since the month of July.

Another benefit is the elimination of nitrification caused by chloramines, which has been problem in the distribution system since 1993. There was no nitrification this summer, and the reason is the use of chlorine dioxide. Mr. Thomson explained that Chlorine Dioxide is formed using Sodium Chlorite and Chlorine, and when the Chlorine Dioxide reacts, it results in chlorite residual. The Chlorite acts as a disinfectant to inhibit bacterial growth. This summer was the first time we did not have to take tanks out of service to clean and disinfect them. He noted that the capital costs are very low, but the chemicals are expensive. Sodium Chlorite alone is costing Sweetwater Authority $8,000 to $9,000 per month, and the average cost for the chemicals is about $4 an acre-foot.

Mr. Thomson ended his presentation by remembering the Lone Ranger and his silver bullet. He is hoping that the Chlorine Dioxide will be the silver bullet that will eliminate the "monster" (THM's).

APPROVAL OF MINUTES

Director Pocklington made a motion, seconded by Director Doud, that the Board approve the minutes of the regular adjourned meeting of December 17, 2004. The motion carried.

APPROVAL OF DEMANDS AND WARRANTS

Director Doud made a motion, seconded by Director Alkire, that warrant numbers 10205 through 10214 be approved. The motion carried.

APPROVAL OF DIRECTORS' ATTENDANCE AT MEETINGS & FUTURE AGENDA ITEMS

Director Pocklington made a motion, seconded by Director Doud, that the Board approve per diem for Director Alkire's attendance at the Otay Water District Pump Station Groundbreaking Ceremony on December 16, 2004. The motion carried.
NEW BUSINESS

Local Agency Formation Commission (LAFCO) - Call for nominations for a regular Special District Member:

Director Pocklington spoke to the subject. His opinion was that at this time there was no need to submit any nominations from this Board. This issue is to be filed without action.

REPORT OF TREASURER

Ms. Avery said that the interest rates are climbing up, which will help to have a balanced budget by the end of the year.

REPORT OF LAFCO SPECIAL DISTRICTS ADVISORY COMMITTEE MEMBER

Director Alkire did not have anything to report since the January meeting had been cancelled.

REPORT OF LAFCO SPECIAL DISTRICTS REGULAR MEMBER

Director Pocklington said there was no meeting in January. The consolidation of the fire districts will be the biggest problem for the year 2005 and it will be on the agenda for the February meeting.

REPORT OF SAN DIEGO COUNTY WATER AUTHORITY REPRESENTATIVE

Director Pocklington said there was not much to report since they have not had a meeting. He commented on the Committee for Committees, of which he is a member, and explained its purpose. The Committee reviews the requests of the Board members regarding the committees to which they would like to be appointed, and also who will be appointed as chairman and vice chairman of each committee. He also commented on the possibility of the CWA increasing its capacity fees.

DIRECTORS' COMMENTS

Director Pocklington said he was at Loveland on Saturday and stopped at the bridge and saw that there was quite a bit of water going into Loveland. He intended to stop at the fishing area, but it was closed.

Director Salas said that she had the opportunity to go on a tour of some of the Sweetwater Authority facilities, including the Loveland reservoir. General Manager Bostad and Operations Manager Rogers showed her the Sweetwater watershed area. She said that the water was plentiful and it was seeping out from everywhere in the surrounding hillsides. It was a great day to be there and she really appreciated the tour.

CLOSED SESSION

There was none.

ADJOURNMENT

With no further business before the Board, President Welsh adjourned the meeting at 4:15 p.m., to the hour of 3:30 p.m., on February 21, 2005.