TRANSMITTAL LETTER FOR BOARD MEETING OF DECEMBER 6, 2012
COMMITTEE ON MONITORING AND RESEARCH
Mr. David St. Pierre, Executive Director
Title
Report on White Paper Regarding Weed Control Through Best Management Practices at the Metropolitan Water Reclamation District of Greater Chicago's Facilities
Body
Dear Sir:
The purpose of this letter is to provide guidelines for reducing the use of chemical pesticides and herbicides on Metropolitan Water Reclamation District of Greater Chicago (District) properties. The best management options presented here include the selective use of herbicides to achieve a balance that has minimal impact on the environment while maintaining quality landscaping and profitable farming.
Background
The District owns and operates seven water reclamation plants (WRPs) and dozens of other facilities, such as solids management areas, pumping stations, and reservoirs. All WRPs have large tracts of land under conventional landscape (vegetated with turfgrass, ornamental trees and shrubs) and native prairie landscape (NPL). The land at the Hanover Park WRP also includes Fisher Farm, which is leased to a contractor for growing corn. The District owns over 5,650 acres of farmland at its Fulton County (FC) site that it leases to local farmers for growing corn, wheat, soybean, and hay. In addition, all WRPs have small tracts of land that are not landscaped. These include areas around electrical substations, which have to be kept free of vegetation to prevent power interruptions and personnel hazards, and small gravelly parcels surrounding primary and secondary tanks and digesters, where vegetation cannot be maintained because these parcels are too small and too close to sensitive infrastructure. There is increasing interest in minimizing the use of chemicals and fertilizers on land to reduce their environmental impact, such as contamination of surface and groundwater. Options for reducing the use of herbicides and fertilizers in land management range from complete elimination to selective use combined with the best management practices (BMPs) to achieve better landscaping with a minimal impact on the environment.
The District's Strategic Business Plan focuses on finances, employees, the natural environment, and the public. Landscape management at the District's facilities impacts all of these aspects of the Strategic Business Plan. Maintenance of weed-free, aesthetically pleasing, and functional landscaping must be financially affordable, provide a symbol to the employees of the highest quality standards of the organization, be harmonious with and complimentary of the natural environment, and present a good image to and be an amenity for the public and surrounding communities.
Objective
The objective of this white paper is to evaluate various weed control and vegetation management options for managing District-owned lands and to recommend the options that are consistent with the District's Strategic Business Plan to guide weed control and vegetation management at the facilities of this world-class organization.
Land Management Strategy
This paper is focused on weed control and vegetation management on five types of land that occur at District facilities: 1) turfgrass, 2) planting beds vegetated with ornamental trees and shrubs, 3) NPL, 4) areas around sensitive infrastructures, and 5) farmland.
Turfgrass
The District's open green spaces consist of over 400 acres of turfgrass at its WRPs and pumping stations. Turfgrass has been utilized by humans to improve the environment for more than ten centuries. A beautiful green lawn is not only aesthetically appealing, but it also provides several environmental and health benefits. For example, a healthy and thick turfgrass cover provides protection against soil erosion by water and wind, and it greatly reduces sediment-linked nonpoint pollution in surface streams, rivers, and lakes. Turfgrass also provides ecosystem services by supporting healthy earthworm populations. Aesthetic benefits of turfgrass include improved mental health, increased worker productivity, and an overall better quality of life, especially in densely populated metropolitan areas (Beard and Green, 1994)1 In addition, turfgrass abates noise, reduces glare, and dissipates the heat-reducing energy required to cool nearby homes and commercial buildings in metropolitan areas (Parsons et al. 1998)2.
The conventional turf landscape consists of turfgrass that is non-native to the local ecological conditions and requires extensive care and maintenance, including use of fertilizers for promoting growth and application of herbicides for controlling weeds. Without fertilizer application or weed control, turf growth on conventional landscaping is very slow, becomes overrun by weeds, and the landscaping is not aesthetically pleasing. However, one drawback of the use of herbicides and fertilizers for maintaining turfgrass is the potential impact on the environment. Various options for maintaining turf landscape at District facilities include:
1. No Herbicide or Fertilizer: No herbicide or fertilizer application leads to turf that is of poor quality and heavily infested with weeds, like dandelions and crabgrass, leading to the District's inability to realize the full aesthetic benefits from its open green space and fosters propagation of invasive weed species on District properties and surrounding communities. Thus, this option is not consistent with the District's Strategic Plan.
2. Frequent Mowing: Another option to maintain turf landscape without using herbicides is to mow the grass frequently. Frequent mowing will help to minimize propagation of invasive weed species and keep annual weeds in check but will not be effective in eradicating the perennial weeds. Besides, more frequent mowing increases maintenance costs and has a negative environmental impact as it requires larger quantities of fossil fuel. Thus, this option is not consistent with the District's Strategic Business Plan.
3. Topdressing with Biosolids and Selective Herbicide Application: Topdressing with biosolids in combination with selective herbiciding will improve the quality and aesthetics of turf landscape at the District's facilities by producing dense turf and inhibiting the propagation of noxious weeds. This is consistent with the District's Strategic Business Plan as it provides a more conducive
environment for employee productivity, improves our public image, and will be more harmonious with the natural environment. This approach also facilitates low cost management of biosolids.
The current general landscape maintenance contract (10-665-11) awarded on July 8, 2010, has provisions to use biosolids for topdressing selected turf areas at the District's facilities. To take full advantage of topdressing with biosolids, the following protocol will be followed for two years:
1. Slit-seed or hydroseed to increase turf density ($110 per acre).
2. Topdress annually with biosolids (about 20 dry tons biosolids/acre) using a proper spreader to ensure uniform application ($120 per acre).
3. Apply broadleaf herbicide (Trimec® 992) to control weeds ($175 per acre).
Slit-seeding or hydroseeding is required only in the first year, and herbicide application is needed only during the first two years. Topdressing with biosolids for two consecutive years would result in thick and healthy turf capable of suppressing weeds without any additional use of herbicides. Following the two years, further maintenance of healthy turf thereafter would require topdressing with biosolids once every three years. The success of this approach in improving the quality of turfgrass has been demonstrated on a one-acre demonstration plot located at the Stickney WRP (Photograph 1, attached).
Planting Beds
Planting beds provide wildlife habitat in urban environments, and well-maintained planting beds beautify and enhance the aesthetic value of turf landscape. Poorly maintained and unmanaged planting beds are not only unsightly, but they will also become a seed bank of noxious weeds that will eventually disperse to neighboring properties, gradually degrading the aesthetics of the community. Some of the high visibility areas at the District's facilities have planting beds landscaped with ornamental trees and shrubs. Conventional management of planting beds includes mulching and application of pre-emergent and post-emergent herbicides to control both annual weeds and perennial invasive weeds like thistle. The District currently maintains approximately 16 acres of planting beds using this conventional practice. Options to maintain planting beds at the District's facilities include:
1. Mechanical Weed Control: Without the application of herbicides, the planting beds could be overrun by noxious weeds in about two to three growing seasons, which will choke the growth of desirable trees and shrubs. Mechanical weed control is an option to maintain planting beds without using herbicides. However, mechanical weed control is not very effective, and hand-pulling weeds generally results in multiple plants because noxious weeds, such as thistle, have deep roots which break easily when hand-pulled and produce multiple sprouts. Mechanical weed control generally results in soil disturbance, which exposes additional weed seeds from the seed bank. Furthermore, mechanical weed control requires intensive manual labor and will be prohibitively expensive given the District's current labor rate of $25.50 per hour. Mechanical weed control will cost the District over $27,000.00 for a single weeding of 16 acres of planting beds, and the yearly maintenance cost could range from $378,000.00 to $432,000.00 because 14 to 16 mechanical weedings per growing season are needed to maintain planting beds weed free without using any herbicides. Thus, the option to use mechanical weeding for maintenance of planting beds is not consistent with the District's Strategic Plan.
2. Weed Prevention Fabric and Mulching: Installation of a weed-prevention fabric and a fresh layer of mulch can be done to rehabilitate and maintain existing planting beds without using herbicides. However, installation of a weed prevention fabric is very expensive as it requires removal of existing mulch, which is labor intensive. In addition, over time, this option eventually requires mechanical weeding because weeds will start to grow on top of mulch, and their roots could compromise the integrity of a weed-prevention fabric, usually within two to three years. Thus, maintenance of planting beds using weed prevention fabric in combination with mulching is less effective, requires intensive manual labor, and will be very expensive given the District's current labor rate of $25.50 per hour. The cost of weed prevention fabric installation with a four-inch layer of mulch for the 16 acres of planting beds is approximately $1.1 million dollars. An additional cost of $81,600.00 - $136,000.00 per year will be incurred for three to five mechanical weedings to remove aggressive weeds that grow on top of mulch. Thus, maintaining planting beds using a weed prevention fabric and mulching is not consistent with the District's Strategic Business Plan.
The most effective and economical option to properly maintain planting beds for creating an aesthetically pleasing environment for employees and the surrounding community is to use mulching in combination with spot herbiciding. We recommend the planting beds be mulched every year in the spring and then sprayed with a post-emergence broad spectrum (glyphosate-based) herbicide on an as-needed basis to eradicate noxious perennial weeds, such as thistle and teasel, and to keep the unsightly annual weeds in check. This is an ecologically friendly option because it requires only selective use of environmentally safe herbicides and does not require application of any highly toxic and persistent pre-emergence herbicides. Unlike blanket spraying, spot weed control utilizes very small quantities of herbicide. Maintaining planting beds using mulching and selective weed control with Roundup® at the District's facilities is consistent with the Strategic Business Plan.
Native Prairie Landscape
The establishment of NPLs is becoming increasingly popular because of its environmental, economic, and societal benefits. Beginning in 2003, the District converted approximately 63 acres of conventional turfgrass landscaped areas into NPLs at its seven WRPs, the Lawndale Avenue Solids Management Area and the Mainstream Pumping Station. A well-established NPL is easier to maintain than turf landscape, and it does not require fertilization or herbicide application. However, the District's NPLs are fairly young and not yet well established. In addition to annual burning, optimum weed control on young NPLs includes selective herbicide application until these NPLs are fully established. The District has invested significantly (approximately $4,000/acre) in the NPL conversion. Without selective herbiciding to control invasive weeds, the NPLs will not only deteriorate to become unsightly weed patches within three to five years, they will also serve as seed banks of noxious weeds for the entire greater Chicago area because the District's NPL sites are scattered throughout Chicagoland. This is not consistent with the Strategic Business Plan and should be rectified as follows:
It is recommended that the District's NPLs receive spot applications of glyphosate-based herbicide, such as Roundup®, on an as-needed basis for the next five years or until these landscapes are well established.
Areas Surrounding Sensitive Infrastructures
These parcels include areas around electrical substations, primary and secondary clarifiers, and digesters and are required to be kept free of vegetation due to limited access, safety hazards, and operational constraints and logistics. For example, Commonwealth Edison (ComEd) requires that the areas surrounding electrical substations (five such areas at the Stickney WRP alone) should be maintained free of vegetation due to safety hazards and to prevent a short-out of high-voltage equipment. These areas have limited access, and prior authorization from ComEd and the presence of ComEd personnel are needed to enter these sites, which often results in extended delays due to the required coordination among District personnel, ComEd, and the landscaping contractor. Currently, the District has over 2.5 acres around electrical substations and over ten acres of gravel surrounding clarifiers and digesters that have to be kept free of vegetation. Conventional management of these areas includes application of pre-emergence and post-emergence herbicides to control vegetation. However, some of the currently used pre-emergence herbicides are highly toxic and persistent in the environment and may have a negative ecological impact. So, this practice is not consistent with the District's Strategic Business Plan. Other options to control vegetation in gravel areas and parcels surrounding the electrical substations at the District's facilities include:
1. Mechanical Methods: Mechanical methods, such as mowing or hand-pulling, are not suitable for controlling vegetation in small parcels surrounding the electrical substations and gravel areas around clarifiers and digesters because these methods are less effective and have to be repeated two to three times a month during the growing season, requiring frequent coordination among ComEd, District personnel, and the contractor. Overall, mechanical methods are highly labor-intensive and expensive. Another option to keep the areas surrounding sensitive infrastructures vegetation free is to install weed prevention fabric underneath the gravel. As explained earlier, this option is labor-intensive and expensive. Both of these options are not consistent with the District's Strategic Business Plan.
2. Permeable Pavement: Installation of permeable pavement is an excellent option to keep the areas surrounding sensitive infrastructures vegetation free as it offers additional environmental benefits, such as stormwater mitigation. However, permeable pavement is expensive to install ($6.00 - $12.00/square foot), and it requires regular maintenance to ensure its integrity for optimal performance. Therefore, this option is not consistent with the District's Strategic Business Plan.
We recommend the use of environmentally safe herbicides, such as Roundup®, on an as-needed basis to control weeds and the excessive growth of vegetation in small parcels surrounding the electrical substations, primary and secondary clarifiers, and digesters. Since these parcels are widely distributed and represent only a small fraction of District-owned land, the potential for an environmental impact of herbicide application on these parcels is minimal. This practice is consistent with the District's Strategic Business Plan.
Farmland
The District-owned farmland consists of over 5,650 acres at FC and about 100 acres at the Hanover Park WRP Fischer Farm. The farmland at FC is leased to local farmers for growing hay and row crops, such as corn, soybean, and wheat. Current farming practices are highly mechanized, and a majority of farmers in Illinois grow genetically modified crops, such as Roundup Ready® corn and soybean. This practice helps to maximize yield and profit because Roundup® can be used for non-selective chemical weed control without affecting the actively growing crops. Therefore, if no herbicides are used on these farmlands, the farmers will be unable to take advantage of the Roundup Ready® high yielding crop varieties. This will cause the lease value of District farmland at the FC site to decrease significantly. Total rent cash income for 2011 for the FC farmland was $879,791.65 and expected to be $930,000.00 for 2012. According to the current FC farm manager, it will be difficult for the District to find any farmer interested in leasing the farmland at FC if the use of Roundup® for non-selective weed control is prohibited.
Application of Roundup® has been proven to be the most effective option for controlling noxious weeds in corn and soybean. Roundup® does not persist in the soil and has not been shown to result in surface water or groundwater contamination. Besides, most of the fields at FC are bermed, and all runoff water generated from these fields is collected in basins where it is held to facilitate settling of sediments before discharging into a nearby stream. This practice further minimizes any potential environmental impact of herbicide loss due to runoff from the farm fields at FC. The current farming practices at FC are consistent with the District's Strategic Business Plan, and we recommend that the District continue using Roundup® for weed control on FC farmland.
At the Fisher Farm, liquid biosolids from the Hanover Park WRP are applied by injection as a fertilizer. The farm is used for corn production annually by a contract farmer. Use of Roundup® for weed control allows the farmer to plant high-yielding, Roundup Ready® corn, which decreases the cost of corn production on the farm. If chemical weed control is prohibited on Fisher Farm, the farmer will be forced to grow conventional corn varieties and rely on labor-intensive and less effective mechanical weed control, which will result in a lower crop yield and net profit. As a result, the District will have a hard time finding farmers interested in leasing the farmland and may have to pay someone to farm this land, thereby turning a revenue stream (approximately $7,500 in 2011) into an expense. In addition, the current farming practice allows the District to beneficially utilize its biosolids.
Application of Roundup® at Fisher Farm has a minimal environmental impact because this herbicide does not persist in the soil and does not result in surface water or groundwater contamination. Besides, drainage and surface runoff from Fisher Farm are collected and pumped back to the Hanover Park WRP for treatment. The current farming practices at Fisher Farm are consistent with the District's Strategic Business Plan, and we recommend that the District continue to allow the use of Roundup® for weed control at Fisher Farm.
Conclusion and Recommendations
Based on our evaluation, we recommend the following BMPs for maintenance of weed-free, aesthetically pleasing, functional, and financially affordable landscaping, and environmentally friendly farming operations, which would be harmonious with and complimentary of the natural environment and would serve as a symbol to the employees of the highest quality standards of the District:
· Turfgrass Landscape - Slit-seed or hydroseed to increase turf density in the spring, topdress with biosolids in the summer, and apply a broadleaf herbicide for two consecutive years to establish thick, healthy, and weed-free turf.
· Planting Beds - Apply mulch in the spring every year and spray with Roundup® on an as-needed basis to control noxious perennial weeds, like thistle and teasel, and to keep annual weeds in check.
· Native Prairie Landscaping - Spot-weeding with Roundup® application on an as-needed basis to control invasive weeds until the NPLs are well established. Continue conversion of additional acreage of traditional turfgrass landscape into low maintenance, prairie-like landscape.
· Small Parcels Inaccessible or Around Sensitive Facilities - Application of Roundup® on an as-needed basis to control weeds and excessive growth of vegetation.
· Farmland at FC and Fisher Farm - Growing Roundup Ready® corn and using Roundup® for weed control at both FC and Fisher Farm are consistent with the District's Strategic Business Plan.
The implementation of BMPs on District-managed land, as recommended in this paper, will help the District achieve the best quality open spaces that are harmonious with and complimentary of the natural environment while maintaining safe and efficient operation of District facilities and profitable farming operations.
The M&R and the Maintenance and Operations Department are working together to implement these recommendations.
Selection of Herbicides
Targeted use of chemical herbicides on District land, as summarized herein, will have an insignificant effect on surface and groundwater. The amount of herbicides needed for spot weed control in NPLs and other landscaped areas are too small to cause any environmental impact. Information about the District's NPLs and the amount of herbicide required for spot herbiciding each parcel is given in Table 1 (attached). The alternatives to chemical weed control are considerably more expensive, laborious, ineffective, and inefficient, making them incompatible with the District's Strategic Business Plan. Roundup®, one of the most commonly used herbicides, is included in the group of "third generation" herbicides which are considered less toxic and ecologically safe. The United States Environmental Protection Agency (USEPA) considers glyphosate, the active ingredient in Roundup®, to be relatively low in toxicity and without carcinogenic or teratogenic effects (USEPA, 1993).3 Rodeo®, a formulation of glyphosate, is considered to be safe for application even in standing water. Similarly, Trimec® 992 is considered an environmentally safer broadleaf control herbicide. Some information from the Material Safety Data Sheet for Trimec® 992 and Roundup® is given in Table 2 (attached).
Organic herbicides, such as corn gluten and BurnOut Weed and Grass Killer (BurnOut), have been promoted as substitutes for synthetic herbicides. However, these alternatives are not only cost prohibitive but are also far less effective than synthetic herbicides and require more frequent applications to control weeds. For example, corn gluten is approximately ten times more costly than Roundup®, and it is only moderately effective as a pre-emergence herbicide. Similarly, BurnOut is only effective on younger weeds, i.e. two to three weeks after germination, and requires multiple applications to prevent weeds from resprouting because, unlike synthetic herbicides such as Roundup®, it does not destroy weed roots. Thus, the use of organic weed control alternatives is neither economical nor environmentally sound because they need to be applied more frequently and at much higher application rates. This will not be consistent with the District's Strategic Business Plan.
Footnotes
1Beard, J. B. and R. L. Green. "The Role of Turfgrasses in Environmental Protection and Their Benefits to Humans." J. Environ. Qual. 23:452-460, 1994.
2Parsons, R,. L. G. Tassinary, R. S. Ulrich, M. R. Hebl, and M. Grossman-Alexander. "The View From the Road: Implications for Stress Recovery and Immunization." J. Exp. Psych. 18:113-140, 1998.
3USEPA, R.E.D. Facts, Prevention, Pesticides, and Toxic Substances Division. Unites States Environmental Protection Agency, EPA-738-F-93-011. September, 1993.
Respectfully Submitted, Thomas C. Granato, Director of Monitoring and Research, TCG:LSH:cm
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