From the Lowry Community Master Association’s arborists at Preservation Tree Care:

Starting this March, Denver water will adjust the pH level to reduce the risk of lead and other metals contaminating drinking water from lead service lines or household plumbing. Here’s what you need to know pertaining to your irrigation and plant material.

What does this mean for my plants?

* Much of the plant material in our landscapes prefer an acidic soil (below 7.0)
* Raising the pH from 7.8 to 8.8 makes the water 100 Billion times more alkaline.
* Consistent irrigation will begin to raise the pH of the soil locking out certain essential nutrients and salt will build in the soil.
* Nitrogen, iron, manganese, copper and zinc will be the most affected.
* These nutrients are required for chlorophyll production and plant health.
* Without these essential nutrients plants will begin to suffer and decline.
* Increased salts in the soil require additional water for adequate hydration. It can take 3 times the amount of water to hydrate plants when salt levels are elevated.

What can I do?
* Use a fertilizer program designed to reduce sodium, improve soil quality, lower pH, and add and free up essential nutrients in the soil.
* Install a fertigation system on your irrigation to treat the water before it reaches your plants.
* Monitor the soil profile by taking soil samples and having them tested by a qualified laboratory.

Fertigation is the injection of fertilizers, used for soil amendments, water amendments and other water-soluble products into an irrigation system. Fertigation is related to chemigation, the injection of chemicals into an irrigation system.

DENVER WATER STATEMENT

“Denver Water has been and continues to work with irrigation and landscape experts locally and nationwide to learn more about any potential impacts from the pH increase.

The feedback we’re hearing so far, from scientists and experts in other cities where the water has a higher pH level, is that in general there should not be any major impacts on plants and landscapes. Specific plants and circumstances may call for best management practices to be used.

During irrigation, such as using sprinklers, pH levels in the water drop when it is exposed to the CO2 (carbon dioxide) in the air. We’re also hearing from soil scientists that the higher pH should not be a problem due to the natural buffering capacity of the soil that helps prevent major impacts on plants.

Denver Water is continuing to work with experts and other cities who have plants and parks in this pH range to learn more so we can appropriately communicate any best management practices that may be necessary to help mitigate any anticipated issues.”