Sonoma County Gazette, March 2014: Guerneville Sewage Spill

Major pipe break causes raw sewage spill into Russian River….
Leaking ‘water’ was reported near the Vacation Beach pump station late in the day on February 12th. When Water Agency crews were on site the following day, attempting to repair a leak, the 16” pipe broke and began spewing about 40,000 gallons an hour of raw sewage that ended up in the river nearby. It is estimated that about 100,000 gallons entered the river before a vacuuming operation began transferring the still leaking sewage to eight tanker trucks holding up to 5,000 gallons each and transporting it to the nearby treatment plant for processing. The pipe was repaired by early the next day.

This event came a few days after a four day period of heavy rain that dropped about a foot of water in the general area. Because of leaky pipes throughout the system, it is likely that excessive water entered the pipes. The break was located near the end of the collection system where it was probably under heavy pressure to move vast amounts of collected sewage after a significant rain event.

Water quality tests of the river were conducted for pathogen indicators (total and fecal coliform), ammonia and dissolved oxygen. We were not informed of any toxicity testing however, which may not have been required by Regional Board or Public Health. To Water Agency’s credit, notices were broadly distributed and many parties were kept apprised of events. Workers appeared to do all they could to respond quickly under difficult circumstances and no problems were noted in the river.

Difficult environment exacerbates many problems…..
Water Agency staff initially blamed the spill on heavy flows and aging pipes. But the 16” concrete pipe was put on line about 30 years ago, and similar pipes have been known to last as long as 100 years. This system has had problems since its inception, when sewer pipes may not have been put in correctly in the first place. For many years there were numerous system leaks and many fines and penalties for spills resulting in river pollution. Some improvements have been made to the treatment plant over the years, but little to the collection system.

Construction history of RRCSD involved multiple lawsuits between County and contractors. There were many unforeseen problems arising during construction such as buried redwood stumps, tree roots in path of pipelines, soil and compaction problems (collapsing soils) and high water tables, etc. (There were about 30 change orders to construction contracts.) Mercury laden rock (cinnabar) was used for pipe beddings, and complete maps of water pipelines during construction weren’t available. The sewer was bid for about $13 million and ultimately came in at more than twice that amount. Construction problems became a source of maintenance issues as well.

The treatment plant was supposedly designed to handle up to 3.5 million gallons (mg) of peak flow, but no more than 1.8 million gallons per day (mgd). In 1995, the year that SCWA took over the system from County Public Works, data indicated that as much as 10 million gallons a day went through the plant during the January 10th flood that was second highest of record at 48’. There was another flood in March of that year, and break downs of the system occurred both times. Furthermore, during a plant tour a few years ago, we overheard staff say that about 8 mdg went through the system in the 2006 flood. (We don’t know yet how much sewage went through during this last rain event.) While it is true that several improvements have been made to the treatment plant in the last ten years, there is still need for much more storage to accommodate excessive flows.

Drought brought false sense of security…..
For about the last 8 years, system leaks have not caused problems due to our extended drought. The last major flood had been on New Year’s Day, 2006, when the river reached 42’ at Hacienda (32’ is flood stage in Guerneville; the highest flood of record was just under 49’ on Feb. 18, 1986.) Rainfall this year had been intense from February 9th to 11th bringing about a foot of water to the Guerneville area. But ground and trees had been so dry, and with no river flooding, the treatment plant seemed to operate problem free during recent storms. And we have seen no water flowing in Armstrong Redwood’s creeks.

Contrasting flows at Hacienda measured about 200 cubic feet per second (cfs) on Feb. 7th, whereas on Feb. 9th and 10th they rose to 15,300 cfs. On Feb. 13th flows were already back down to 1900 cfs and 1200 cfs on the 14th. Our very ‘flashy’ river comes up and goes down quickly, even while waters still drain from our Guerneville hillsides. (If our information is correct, we wonder whether 100,000 gallon spill in three hour period on Feb. 14th was less than 1% of river flow as stated by SCWA staff?)

Rain water augments sewage…..
When rain water leaks into the system and contacts sewage, it’s all considered sewage by water quality control officials and must be treated accordingly. When pipes and plant are overloaded, it puts extensive pressure on the system and other problems may result, such as treatment by-pass. Since large amounts of sewage regularly pass through the area of this break near the end of the collection system, and are most intense during times of heavy rainfall, pipeline monitoring should regularly take place to discover problems before they occur.

Regular collection system maintenance needed….
While Russian River County Sanitation District ratepayers have some of the highest sewer rates in the County, it is questionable whether regular collection system maintenance has been taking place. According to publicity sent out by the District with last year’s fee increase notice, one chart (Figure 2 on page 4) indicated that an average of about $3 million a year went for operations, and about $200,000 was spent on maintenance during two of the five years noted on the chart.

Two other years, less than $1 million was spent on maintenance and the publicity does not reveal for what kind, but in 2009 about $5 million was spent, which may have been allocated to the new disinfection facilities and probably not spent on collection system maintenance. We wonder why maintenance costs were so variable? If the collection system is aging and in need of repairs, then a much larger percentage of our fees should be allocated on a routine basis for this purpose.

And finally….
It will be interesting to read all the details when spill report is released. (We do not believe there’s been no environmental harm as stated. Many tests would be needed to make a definitive declaration regarding the harm that may have occurred and only a few have been ordered thus far.) At the very least, the collection system should be tested regularly to discover in advance of spills whether any repairs are necessary.