Showing posts with label Disinfection By Products. Show all posts
Showing posts with label Disinfection By Products. Show all posts

Monday, January 23, 2017

My experiences while serving as an At-Large member of the Gloucester County, Virginia Public Utilities Advisory Committee (PUAC) (The 4th in a series of articles about my experiences and findings)



Our Public Water Distribution System

Once our drinking water is processed at our treatment plants it is pumped into our mostly underground pipe distribution system. I say mostly underground because within our system there are three elevated water storage tanks commonly referred to as water towers. These towers are where our water is stored to readily accommodate customer demand. Ideally in water systems like ours where hydraulic pressure created by elevating the storage tanks (gravity) eliminates the need for electricity powered pumps to deliver water under pressure to customers, elevated water towers should be constructed at as close to the same capacity and elevation as possible. There are numerous reasons for building water towers like this; of which include water quality, pressure control and system costs. Unfortunately our water towers were not built that way.

Our public water supply system began in the Courthouse area back in the 1950’s. A separate water tower and public supply system was constructed in the Gloucester Point area in the early 1970’s. The two systems were connected together and our third water tower was constructed in the mid 1990’s. Our public water supply system now has a 250,000 gal water tower located in the Courthouse area, a one million gal tower at the old Page Middle School site and a 250,000 tower at Gloucester Point that are all connected together and to our water treatment plants. The Courthouse tower’s full water elevation is 198 feet above sea level, the Page tower was constructed with a full elevation of 215 feet above sea level and the Point tower has a full water elevation of 160 feet above sea level. As can be seen, the Courthouse and Page towers are quite a bit higher in elevation than the Point tower, with the Page tower, geographically located in between the other two, being the highest and largest of the three.

I am of the opinion that the Page water tower was built at the elevation it was to facilitate water requirements associated with the Gloucester Business Park where Canon and other businesses are located. In other words; the good ole boy system was working at its finest.  

The differences in our water tower sizes and elevations make it hard to control water quality in the Courthouse and Point water towers; I’ll explain. Once a water tower is filled, the supply to the tower is supposed to be turned off until the level of water in the tank drops to a specified level. Once the specified level is reached the supply to the tower is turned back on until it is full again. This fill, drop scenario is commonly referred to as water turnover and is supposed to occur continuously. This does not happen at the Courthouse and Point towers because the Page tower is so much larger and higher in elevation that it causes the other two towers to constantly remain full. When stored water does not get turned over frequently and regularly, disinfectant byproducts (DBPs) begin to consolidate.

DBPs are chemical, organic and inorganic substances that can form during a reaction of a disinfectant with naturally present organic matter in water. There are too many types of DBPs to list here but many are suspected of causing damage to the bladder, liver, kidneys and central nervous system. Some are also considered carcinogenic.

In order to achieve sufficient water turnover in the Courthouse and Point tower; Utilities employees must manually lower the water level in each tower by dumping water from the tanks onto the ground. Unfortunately, it does not appear Utilities has always been consistent in turning the water over in these towers. I believe our current Utilities employees do a much better job making sure DBPs do not build up, but I also know Utilities has sent high level DBP notifications to customers in the Gloucester Point area within the last year. I am unsure of the source of the DBPs that drove customer notification in the Point area because DBPs are known to consolidate in other areas of a water supply system. I do know the DBPs customers were warned about at the Point are associated with bladder cancer.

Our system currently has underground water supply lines that run along Short Lane Road, Guinea Road, Terrapin Cove Road, Providence Road and other roads, streets and cul-de-sacs  in which the waterlines dead end. Dead end lines such as the ones noted are also areas where DBPs are known to consolidate. This problem was first brought to my attention during my first visit to our water treatment plants. The statement made to me was to the effect of no one being able to guarantee that water high in DBPs was not consumed at T.C. Walker School which is supplied by the Short Lane Road waterline. It was added that it probably was consumed over a number of years. T.C. Walker is not our only public school connected to our public water supply system in this manner, as Achilles Elementary School is supplied with water from the end of the dead end Guinea Road waterline. An automatic flushing device was added to the Short Lane Road waterline about a year ago and Utilities’ current leadership has implemented a regular flushing and monitoring schedule that should prevent DBP consolidation in the other dead end lines.

Regularly flushing waterlines and fire hydrants is part of operating and maintaining a public water supply system. Like everything else I have talked about in these articles; regular flushing of our waterlines is something that did not occur for many years due to mismanagement and neglect. Now we have buildups of sediment in the bottom of many of our waterlines which causes many customers to end up with cloudy water in their sink whenever a fire hydrant is opened. Exercising valves and hydrants is part of any good flushing plan, but again, is something that was neglected in Gloucester for years. Now we have many valves in our system that will not close completely when needed. Utilities’ new leaders have made some progress in this area through reactionary efforts, but there is a lot more that needs to be done in a proactive and preventive manner.

Some areas of our water supply system are very old and in need of replacement. Utilities’ is constantly repairing leaks and replacing components of the system. Unless there is a much higher priority placed on water quality and accountability, I believe the repairs will continue and will likely intensify until such time as something catastrophic happens. I will share more about our water accountability in a later article.

It will take a rather large financial investment to bring our public water supply system up to acceptable standards and performance. We need to correct our water tower issues. We need to replace our out dated and defective water supply pipes and apparatuses. We need to adopt and enforce up to date construction standards. And we need to establish and enforce policies and procedures that will prevent future neglect and mismanagement of our public water supply system.

In my next article I will introduce our public sewer system. Environment conscious folks will not want to miss it.

Comments may be emailed to: Kennysr61@gmail.com.

Kenny Hogge, Sr.
Gloucester Point, Virginia