Redefining Water Management

Features - Water

Focus your water-management plan to control and maintain water quality through the entire operation

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March 7, 2011

To initiate a comprehensive management plan, start by doing a series of water analysis tests from all water sources and at key points in the water-distribution system.Over the years of working in multiple areas of agriculture, I have come to realize that most growers, whether they’re raising plants or chickens, lack a true understanding of the improvements available from focusing on water quality. The problem isn’t a lack of concern for water quality, but how success is defined when it comes to meeting water treatment goals. Most growers have the wrong goals.
 

Water goals
For many ornamental plant growers “effective water treatment” is defined as having the equipment to prevent mechanical issues that dirty water brings, including clogging of irrigation lines, algae growth, etc. Some growers have gone a step further and determined that disinfecting their water can reduce the incidence of disease. This additional goal is to eliminate potential disease pathogens and receive negative pathogen water test results. Most growers who disinfect their water, resulting in a negative pathogen test, feel comfortable that they have an effective water-treatment system in place.

However, the goal that will yield the greatest returns for growers is making water the most important nutrient they provide to their plants. The way to successfully reach this goal is to install water-treatment systems that provide water in its healthiest form to the plants. Achieving this goal lowers production costs and increases profitability.
Anyone who has been in the horticulture industry for any length of time knows that water treatment is probably the least understood and most often misapplied management tool. There have been numerous so-called “solutions” to water-related problems. Many of these technologies may be perfectly good solutions to a specific set of problems, some of which the industry has, and many which it doesn’t. Some of these solutions may be potentially effective technologies, but used in the wrong applications.
 

Collecting information
The first step in developing a comprehensive water management plan is collecting information. The more informed you are, the more likely that the solutions you choose for your operation will be the right ones. Ask questions, verify the answers and remember it is just as important to know what a technology “will not” do as what it “will” do.

Water treatment purchases are generally viewed as component buying decisions (filters, chemical dosing pumps, etc). Each decision is basically a single point decision made mostly on its own merit, not on how it fits into a well thought-out plan for the growing facility. This way of thinking must change.
 

As you make long-term decisions about the water treatment technologies to incorporate, do so with the knowledge of how each of these technologies helps your business move toward the ability to safely and effectively reuse water.Water analysis
To initiate a comprehensive water management plan, start by doing a series of water analysis tests from all water sources (both fresh and recycled) and at key points in the facility’s water distribution system. Once you have an accurate assessment of the current water quality, the target water quality must be determined at each step in the distribution system.

At this stage of developing a water management plan it can be beneficial to contact competent sources with expertise in evaluating water-quality concerns and the levels of improvement needed to achieve the goals available and the technologies to accomplish these goals. The focus should be on delivering water that produces the healthiest plants possible. This will lower chemical treatments and labor costs, help to minimize shrink and reduce a company’s exposure to environmental and regulatory hurdles.

 

Management plan components
The areas that should be included in a water management plan include: the incoming water source, water collection ponds, pumping systems, piping systems, water holding tanks, flood floor and flood bench systems, spray irrigation systems, drip irrigation systems, monitor and control systems, filtration systems, disinfection systems, chemical and nutrient injection systems, aeration systems and water reuse systems. The objective of the plan is to control and maintain water quality throughout the entire operation and treat it as a renewable resource.

When evaluating these systems and processes it is easy to revert to focusing more on attention-grabbing mechanical issues rather than the new focus of plant health. The mechanical issues related to water management are important. But in almost all cases as plant health issues are addressed, the mechanical ones will be resolved through the same solutions.

A good example is in the area of filtering water in a flood or pressure irrigation system. Filtering water reduces the build-up of solids, which reduces the labor for cleaning storage tanks and nozzles, eliminates stains on floors and benches and prevents clogging of piping systems.

This same problem approached from a plant health perspective might be viewed in this way. The goal is to add filtration to reduce the accumulated organic load in the irrigation water. This accomplishes reduced oxygen demand on the system preventing oxygen deprivation in the water. More oxygen is available to the roots resulting in healthier plants.

Another related plant health issue is biofilm in tanks and piping systems, which acts as a reservoir for potential pathogens. Reducing the organic load in the irrigation system, which serves as a food source for biofilm, slows biofilm growth. Filtration slows but does not eliminate biofilm growth. Biofilm will grow even with very fine particle filtration. Biofilm must be addressed with an oxidizer effective at destroying it. Not all oxidizers are effective at eliminating biofilm and preventing its re-growth.

Incorporating an effective water treatment system may require a finer particle filtration than would be needed to simply reduce the sludge build-up in storage tanks and the distribution systems. So, accomplishing the above goals also accomplishes the obvious mechanical goal. This same process repeats itself throughout the greenhouse as targeted solutions are developed for water-related issues. When these solutions are designed to work together in a comprehensive water management plan, they help provide a more effective line of defense.
 

Don’t forget the environment
As you begin your review of the opportunities to improve water quality and develop solutions keep the environment in mind as well. Your most important renewable resource is water.

Our industry is faced with increased regulatory oversight. As you make long-term decisions about the technologies to incorporate, do so with the knowledge of how each of these technologies helps you move toward the ability to safely and effectively reuse water. If properly planned for, this does not have to be an economic burden.


Charles Hayes is a biochemist and president of Advanced Treatment Technologies,
charlie@advancedtreatmenttechnologies.com; www.advancedtreatmenttechnologies.com.
His company is represented in the horticulture industry by Dramm Water, www.dramm.com.