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Planning  and  Managing  for  Pollution  Prevention
            hen planning a new operation or
            expanding an existing one, you as a
            nursery manager must choose a site
            carefully to avoid environmental
            risks and design the total drainage
            system properly. For example,
            locating your nursery within a
            quarter mile of a stream or lake is
rarely a good choice if you want to prevent water
pollution economically because close proximity to
a waterbody increases the chances that nursery
runoff will discharge directly to a stream or lake.
Designing a drainage system for growing beds,
lath houses, and propagating facilities or
greenhouses so that no untreated drainage leaves
the property will save you thousands of dollars
over redesigning and retrofitting an existing
system for pollution control.
   If you have an established nursery, you
probably do not have the luxury of starting over to
minimize the potential for environmental harm.
Instead, you can prevent and control pollution by
retrofitting your operation and changing
management practices. Some effective BMPs you
should consider:
   • Add a field border around your operation
     with permanent upright grass to slow
     velocity and rapidly growing trees to
     remove nutrients from runoff. (Research has
     shown that poplars have some of the highest
     nutrient uptake rates.)

   • Establish vegetation on the upslope edge of
     the property to slow outside water from
     flowing across your operation.

   • Evaluate your fertilization schedules and
     methods. Use soil and tissue testing to
     ensure optimum — but not excessive —
     growth. Consider changing to a more precise
     application method, such as microfertigation
     (injecting fertilizers through the irrigation
     system) or mechanical incorporation.
     Evaluate the fertilizer in  use: is a form
     available that is less environmentally mobile,
     such as a slow release formula? Install a
     backflow preventer if fertigation is used.
 Evaluate the growing habits and
 requirements of different plant materials and
 species. Match pesticide and fertilizer
 amounts to each plant's specific need so
 species that need less receive less.

 Rearrange your stock on growing beds so
 varieties that need the most fertilization and
 irrigation are located farthest from a
 waterbody or a drainage channel that
 discharges near or into a waterbody.

 Develop and implement an integrated pest
 management (IPM) program that uses pest
 scouting to identify and treat infestations
 before they become severe. Select the least
 mobile and persistent chemical. Explore the
 use of biological controls.

I Use a soil or growing medium that holds
 water better than your nursery's present mix
 (but still provides sufficient aeration and
 drainage) to decrease irrigation frequency
 and amount.

 Assess your irrigation methods and
 schedules. Avoid methods that use
 large-volume overhead sprinklers (almost
 two-thirds of this water runs off carrying
 excess fertilizers, pesticides, and other
 pollutants). Try precision application with
 drip irrigation. Maximize the efficiency of
 existing systems by irrigating when wind
 velocities are lowest.

I Select varieties for production that require
 the least intensive growing methods. Native
 plants often require much less fertilizer and
 water and are much less prone to disease
 and pest damage than introduced varieties.
 Aggressively market these environmentally
 friendly plants.

I Practice source reduction in your weed
 control program by mowing the perimeter of
 your nursery to prevent weeds from going
 to seed; similarly, establish a regular (daily)
 hand weeding schedule for the same reason.

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   Turkey Creek uses several high efficiency filters
(ranging from 20 to 80 microns) in its water
treatment system to remove solids; the water
intake pipe is also screened. Both the water intake
and filters use a back-pressure system to eliminate
clogging. To prevent algae accumulation, 3 ppm of
chlorine is added to the water as it enters the
treatment system.
   After mechanical filtration, the water is treated
in a carbon tank filter system to remove herbicide
and pesticide residues — an important step toward
protecting plant and water quality. These residues
can become increasingly concentrated as irrigation
return water or rainfall runoff water is reused
again and again.
   The final treatment involves an ultraviolet light
system that destroys fungi, bacteria, and any other
waterborne spores. This step prevents the spread
of disease to nursery stock and the discharge of
bacteria-laden water from the nursery. The
treatment system water and any discharge water
(if the system is bypassed in an unusually intense
               storm) is tested at an approved lab for pH, nitrate,
               nitrite, total phosphorus, fecal coliform, and
               certain metals.
                  Turkey Creek has to contend with some unique
               problems that could be avoided in a newer
               nursery. For example, it must manage a
               channelized highway runoff drain (off-site water)
               that flows across the property. The site has little
               natural drainage and much of the irrigation return
               water must be pumped into detention ponds and
               through the rest of the system (including treatment
               and re-irrigation) because little gravity flow is
               available. All blocks, now properly crowned and
               graded to drain to the concrete ditches, originally
               had to be stabilized (as did the roads) because the
               site is located on high shrink-swell clay soil.
                  Turkey Creek recommends that nurseries
               planning to install a pollution control system plan
               in advance (especially in site selection) and devote
               the needed time, effort, and expense to design and
               build the most effective pollution control system
               possible — one that can be expanded as the
               nursery grows.
Case  Study:  Nines  Nursery
          ith almost 250 employees,
          Hines Nursery (also
          located near Houston) is
          one of the largest
          containerized wholesale
          growers in Texas. Hines'
          recycle/reuse system
          includes retention of
          irrigation return flows
and the first half inch of rainfall,
water filtration and  reuse, and
various management methods that
maximize production while
minimizing input.
   Hines has a system of gates,
pump stations, concrete channels,
and ditches to carry (using gravity
flow) irrigation return water to two
holding ponds.  After filtration, the
water is recycled back through the
irrigation system, which consists
mostly of overhead sprinklers.
Before Hines installed its
recycle/reuse system, an estimated
70 to 80 percent of the irrigation
water was discharged and lost.
                       r    -
Sand filters for water treatment at Hines Nursery near Houston, Texas.

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Case  Study:  Turkey Creek  Farms
          urkey Creek Farms, a wholesale
          nursery north of Houston, Texas, uses a
          combination of structural and
          management BMFs to prevent and
          control runoff, irrigation discharge, and
          associated pollution.
            Turkey Creek uses an almost totally
          closed irrigation recycle/reuse system
to manage the more than one million gallons of
water per day needed for its 120-acre facility. The
system includes concrete-lined irrigation return
and rainfall runoff collection ditches that drain to
two clay-lined detention ponds. Water is pumped
from these ponds to a central holding basin and
then goes through a treatment process that
removes solids, organics, pesticides, and bacteria.
The treated water is discharged into a large,
high-density, polyethylene-lined holding tank.
From here, the treated water is either used for
irrigation or pumped to the nursery's original
water supply pond where it is mixed with well
water.
   This system will cost Turkey Creek about
$400,000 when fully completed. Maintenance costs
(including replacement of treatment system
components) are expected to be about $30,000
annually — a considerable investment in a short
time. However, the nursery, which previously used
four 6" wells almost continuously, lowered its
pumping costs considerably
by installing the water
recycle/reuse system and
expects a significant cost
savings over the next few
years. Turkey Creek
recommends that you install
retention ponds first and
follow up with a water
treatment system within  a
year.
   Management BMPs,
usually the least expensive
part of the system, can often
be modified right away. The
nursery uses a mixture of
preventive or good
housekeeping procedures
(e.g., proper disposal of
clippings and silt fences
around bark storage and        Retention pond for irrigation return flow and runoff at Turkey Creek Farms
                              near Houston, Texas.
                                                  potting-up areas) to keep organic materials out of
                                                  irrigation and runoff return water. This practice
                                                  also decreases treatment costs and prevents plant
                                                  damage from mold and fungus. Most plants are
                                                  fertilized with a controlled-release fertilizer to save
                                                  time (the slow-release formulas are designed to last
                                                  10 to 12 months without re-application), decrease
                                                  fertilizer cost (less fertilizer is lost through
                                                  leaching), and keep excess nutrients out of  the
                                                  discharge water.
                                                     As part of its integrated pest management
                                                  program, Turkey Creek uses the least residual
                                                  pesticide and is experimenting with a preventative
                                                  pest control program that incorporates
                                                  pesticide-free oils to coat and smother insect pests.
                                                  The key to this program appears to be a regular
                                                  spray schedule  that is coordinated with the insect's
                                                  growth/rep reductive cycle.
                                                     Drip irrigation is now used on about one-third
                                                  of the plants grown at Turkey Creek; overhead
                                                  sprinklers are still used on the remainder. The
                                                  nursery is evaluating the sprinklers' water  use
                                                  requirements and converting to the drip system as
                                                  expenses allow. To conserve space and use  the drip
                                                  system optimally, the nursery has interspaced
                                                  deciduous trees on racks with smaller,
                                                  low-growing evergreens. Successful use of  a drip
                                                  or trickle irrigation system depends on clean water
                                                  because the tiny emitters clog easily.

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Structural  BMPs
          ow can a nursery keep all runoff or
          irrigation return water on its property?
          Detention ponds, tailwater pits, and
          catchment basins — coupled with
          water recycling — can help your
          nursery get close to that goal. Although
          these systems include an initial design,
          engineering, and construe hon cost, they
often create a significant cost savings because less
water is pumped. While researchers cannot fully
predict environmental cost savings from using
these detention ponds and water reuse systems,
they have found that proper design, installation
(lined to prevent groundwater contamination),
and management can reduce nutrient discharge
concentrations up to 80 percent.
   Success does not depend as much on the
detention pond (normally about 20 percent
effective in removing nutrients) as the
recycle/reuse system that diminishes discharge.
Since they act like settling basins by allowing the
heavier particles to drop out, detention ponds
effectively remove suspended solids and any
pollutants that are adsorbed to sediment particles.
However, using a pond alone is not a particularly
effective method to remove dissolved pollutants,
especially pesticides and some forms of nitrogen.
   Reusing your irrigation water can cause
problems with salinity, nutrient, algae, and bacteria
buildup. Recycled/reused irrigation water may
need treatment to protect nursery stock from
waterborne diseases and frequent testing so the
nutrient concentration can be factored into your
fertilization program. Testing will help  you avoid
over-fertilization  (and its associated scorch or
weedy growth) or nuisance algae growth in ponds.
Investing in a simple testing lab  safeguards your
nursery's investment in container stock.
                                        Growing Beds
                             Reuse
   Discharge
                    Treated Water
                         Pond
                           Filter System
                       and Water Treatment
            Flocculation
                Pond
Diagram of irrigation water management and reuse system for containerized nurseries.

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       Situated in an area with an average rainfall of
    50 to 60 inches annually, the nursery contains 200
    acres of graveled growing beds on both sides of a
    creek. Because of the average high rainfall, Hines
    was concerned about the large water volume its
    system would have to accommodate, so the
    nursery installed several new drainage channels to
    divert the flow from direct discharge into the creek.
       The low maintenance system cost Hines about
    $800,000; upkeep on the water recycling system is
    estimated to be $25,000 per year. The nursery
    expects to save substantially on annual costs
    because of lower pumping expenses.
       One of only a few nurseries in Texas with an
    individual state  discharge permit issued by the
Texas Water Commission (Turkey Creek is
another), Hines collects water samples and sends
them to an independent laboratory for analysis.
Hines uses data from these analyses to improve
production and decrease expenses by modifying
their fertility management program. The nursery
uses both fertigation and controlled-release
fertilizers to grow their products.
   Hines personnel believe the recycle/reuse
system has made them better managers. Although
Hines spent a considerable amount of money over
the past four years to research, design, engineer,
and install its system, the nursery has maintained a
profitable business.
                                             V
                                      TERRENE
                                          INSTITUTE
For additmml iw/ffrmation, contact Susan Alexander, The Terrene Institute, Route I, Box 262, Pimland? TX
75968 (%AjS7-4821), This project was funded by the U.S. Environmental Protection Agency, Region
^mget^t&^rision, Water Quality Management Branch. Prepared by Susan V, Alexander, JT&A,
Qlem Ass^^^in cooperation with the Texas Association of Nurserymen. For copies of this publication and
others l» Jlfipas, contact The Terrene Institute, 1700 K Street, NW, Suite 1005, Washington, DC 20006 (202)
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                                               Printed on Recycled Paper

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