Understanding Our Water

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April 11, 2013 by Omar Passons

One of the main roles our City has is bringing in water for things like drinking and taking out water that’s dirty.  This page is background on bringing water to our homes or businesses. For moving out dirty water (called ‘wastewater’) click here. Getting water from its source (like a river, reservoir or groundwater) to your faucet has many steps. The four most important are:

  1. Transporting it;
  2. Treating it ;
  3. Moving it to your house or business; and
  4. Keeping #1, #2 and #3 maintained and working

#1 – Transporting it

Because of San Diego’s weather, annual rainfall alone does not produce enough water to supply us with fresh drinking water.  Although the City owns and operates ten reservoirs (what’s a reservoir?) around the county, the City must import between 85% – 90% of water each year to meet all the needs of our citizens.  In Fiscal Year 2012, the City spent approximately $208 million just to purchase water from others.

The City purchases water from the San Diego County Water Authority (a separate governmental agency from both the City and the County).  The Water Authority purchases its water from the Metropolitan Water District of Southern California.

The Metropolitan Water District gets its water from both the Colorado River and the State Water Project (Sacramento Delta).

For more information from the City’s Public Utilities Department about sources of water, click here.

#2 – Treating It

The Public Utilities Department uses several methods to clean water at one of three water treatment plants: Alvarado, Miramar and Otay.  These methods include coagulation and flocculation, sedimentation, sand/multi-media filtration and primary and secondary disinfection .  These things may not be in your City Council District, but they are important.  For example, none of these treatment plants are in my community of North Park, but a portion of our water bill goes to pay for them since we need them just as much as the communities where they are located.

To read more about the City’s treatment process, click here.

Side Note: There are alot of misconceptions about treating wastewater and reusing it. The technical term is Indirect Potable Reuse, or IPR. This is one potential additional source of needed water.  To understand for yourself whether you think it’s a good idea for San Diego, here are articles for and against it I couldn’t find opposition easily and I have work to do, feel free to share if you have a link. Here’s a big study the City of San Diego did on the issue. I support it, mostly because I understand the water’s actually cleaner than what we get from the Colorado River, but that’s another issue.  Moving right along.

#3 – Moving It

The Public Utilities Department moves water to our homes and businesses through underground pipes and above ground pump stations.  We don’t usually see these, but they are all over–or under–our neighborhood streets and its how the clean water gets to our faucet.

Like most things, the pipe and pump system has gotten better over time.  The different types of pipes for the Water Main and Sewer Systems differ in their durability.

For Water Mains, there are cast iron (CI) – lasts 50-75 years, Asbestos Cement (AC) and PVC, which lasts 75 years, Reinforced Cement Steel Cyl, and Cast Iron Cement Lined.

For Sewer Mains, there is Vitrified Clay and PVC, which lasts 75 years.

The durability of the pipe matters because it impacts the replacement cost and the burden on our city’s budget.

Quick Answer – Cost Details

As of Fall 2012, the pipes described above cost between $246-$340/linear foot of pipe installed to install new pipes.  The cost per foot also includes needed items such as valves, services, highline, and cut & plug.

Note: Making choices about pipe can sometimes be like deciding between buying a Honda or a Lexus – both get you from one place to the other, but one is more economical while the other is a smoother ride.  Trade-offs are important when we look at the upcoming maps.

#4 – Maintaining It

This is a complicated topic, maintaining the water system involves replacing some things and repairing others.  The Public Utilities Department has some good information about this part here.  As I gather more information I’ll update with other posts.  But let’s get into the basics.

To use the car comparison again, the pipe and pump system is kind of like having different cars.  If you have an old Honda, it might run forever if you just make sure to change the oil and keep the engine tuned up.  But if you have an old, unreliable car, you never know when the ignition will go out, if it will break down on the way to work or if it is destroying the environment with a slow oil leak.

Thinking about our neighborhood, some of our pipes are like Hondas and will last for years.  Some pipes, though, are like the old unreliable car above and we need to replace them to ensure we get reliable water.

One important issue in maintaining our water and sewer system is the cost to monitor it.  This is how you can tell if it is going bad and prevent or minimize breaks.  As with most things, there is a signficant cost to monitor the system, in this case because you have to hire special professionals to go underground with expensive equipment.  The range of costs to monitor our system using “televising” (the specialized cameras) is as follows:

What is the cost is to use cameras (called “CCTV”) to inspect a section of sewer main?

8” to 10” diameter –  $1.30 – 1.50  per linear foot

15” to 36” diameter –  approx. $2 per linear foot

36” and larger – $2.50 per linear foot

The above is an average cost of CCTV inspection from three recent City contracts.  Please note that the price will be higher if the work is in a canyon and/or high traffic area.  There are thousands of miles of these pipes in our system, so you can imagine the cost to do this type of monitoring can be quite high.

THE NEW CAR “GIFT” – Why getting new pipes for free is good AND bad

One important issue in the cost of our system is understanding the impact on things like maintenance and monitoring of being “given” new pipes, which is what often happens if a real estate developer builds a new set of homes in the city.  Here’s an example to make the point.  If someone gave you a new sports car (or hybrid, if that’s your thing), there’d be plenty of reason to celebrate. The car didn’t cost you anything up front, it’s nicer than your current car and really who doesn’t like “free.” When companies build new subdivisions or office buildings they often “give” the city the pipes that connect those properties to the overall system. On the one hand, this is great because the Water Department doesn’t have to pay for the new pipes. It’s like the free car. But if you got a new sports car you’d probably have maintenance bills you didn’t have before such as premium oil and gas and more expensive tires. Plus, you might not have budgeted for the taxes or increased registration. Similarly, even though the City didn’t pay to get the pipes up front, now that it owns them it has to pay for their maintenance and replacement.

Because pipes last for a very long time, the people who were around to accept the “free” pipes are usually gone when the maintenance bill comes due. You could give your new car back or sell it, but the City doesn’t have that choice.

More details in the coming weeks.  Thanks for reading!

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