The Massachusetts Department of Agricultural Resources (MDAR) Public Drinking Water Supply Protection Regulations (State Regulation 333 CMR 12.00, enacted 1/1/1992) are intended to prevent non-point source contamination of public drinking water supply wells from pesticide products on the Massachusetts Groundwater Protection List. Updated annually, the Groundwater Protection List identifies specific pesticide active ingredients that could potentially impact groundwater due to their chemical characteristics and toxicological profile.
Geographic sites protected under the regulations are referred to as primary recharge areas. For pesticide regulatory purposes, a primary recharge area is considered to be either an Interim Wellhead Protection Area (IWPA) or a “Zone II” for wells that have pumping rates of over 100,000 gallons per day (gpd). The Drinking Water Supply Protection Regulations do not apply to wells that pump less than 100,000 gpd.
If a management decision has been made to use one of the pesticides listed on the Groundwater Protection List, then it is the responsibility of the applicator to be aware if the site is within an IWPA or Zone II area, and to act accordingly. For general guidelines about how to comply with the Massachusetts Public Drinking Water Supply Protection Regulations, consult the flowchart in Figure 4 below.
Table 24. Massachusetts Groundwater Protection List (current as of April 1, 2018)
* Denotes active ingredient labeled for cool-season turf use
Figure 4. Do the Massachusetts Public Drinking Water Supply Protection Regulations Apply to You?
1. Do you plan to make a pesticide application within a Zone II or Interim Wellhead Protection Area (IWPA)?
For instructions on how to determine if your application will fall within a Zone II or an IWPA, contact the MDAR Pesticide Program at (617) 626-1771, or visit https://www.mass.gov/pesticides-and-water-supply-protection
If NO, then STOP. You do not need to be concerned about the regulations.
If YES, then proceed to Question 2.
2. Does the pesticide product that you intend to use contain any of the active ingredients listed on the current Massachusetts Groundwater Protection List?
If NO, then STOP. You do not need to be concerned about the regulations.
If YES, then proceed to question 3.
3. Are there any viable alternatives to the pesticide that you intend to use?
If YES, then STOP and use the alternative.
If NO, then proceed to Question 4.
4. Will the pesticide product be applied to an area which has greater than 50% foliar cover?
If YES, then you must confirm the non-viability of alternatives, you must apply the pesticide as part of an Integrated Pest Management (IPM) program approved by MDAR, and you must submit a Groundwater Protection Program Notification Form to MDAR within 10 days of the end of the calendar month in which the pesticide is applied.
If NO (meaning that the pesticide product that you intend to use is soil-applied, or will be applied to an area with less than 50% foliar cover), then you must confirm the non-viability of alternatives, you must apply the pesticide as part of a MDAR approved Integrated Pest Management (IPM) program, and you must verify that a Pesticide Management Plan (PMP) for that use pattern has been approved by MDAR.
For further information on MDAR notification requirements, MDAR approved Integrated Pest Management (IPM) programs and/or a Pesticide Management Plan (PMP), contact the MDAR Pesticide Program at (617) 626-1771.
Turf pesticides on the Massachusetts Groundwater Protection List
Bentazon (Basagran) is used primarily for the control of yellow nutsedge in turf. Possible alternatives to bentazon include halosulfuron and mesotrione. For more information about bentazon, see the Characteristics of Turf Herbicides section of this guide.
Dimethanamid (Tower) is used primarily for the preemergence control of yellow nutsedge in turf. No other material is currently labeled for preemergence yellow nutsedge control. Postemergence control with halosulfuron or mesotrione is an alternative option. For more information about dimethanamid, see the Characteristics of Turf Herbicides section of this guide.
MCPA (several trade names) is a component of several combination products labeled for postemergence control of broadleaf weeds in turf. MCPP has gained favor over MCPA for many formulations in recent years because of higher activity. Thus, viable alternatives are readily available. For more information about MCPA, see the Characteristics of Turf Herbicides section of this guide.
Sulfentrazone (several trade names) is used primarily for postemergence management of a range of broadleaf weeds in turf. It is formulated alone or in combination with additional herbicides. Possible alternatives to sulfentrazone include halosulfuron and mesotrione. See the Characteristics of Turf Herbicides section of this guide for additional information about sulfentrazone.
Chlorothalonil (Daconil and several other trade names) is labeled for use on several major turfgrass diseases in the Northeastern U.S, including anthracnose, brown patch, copper spot, dollar spot, Microdochium patch (pink snow mold), Helminthosporium leaf spot disease, red thread, rusts, and Typhula blight (gray or speckled snow mold). Many alternative fungicides are available for these diseases (see Table 22 in the Disease Management with Fungicides section of this guide). The primary disadvantage of many of the alternative compounds, however, is the potential for fungicide resistance development with repeated use. Because resistance has not been reported for chlorothalonil, it is an important rotation and tank-mix product for resistance management programs (refer to the Characteristics of Turf Fungicides section of this guide for a discussion of fungicide resistance). Also, the broad spectrum activity of chlorothalonil is part of its value as a fungicide. This value is reflected in the relatively frequent use of chlorothalonil on turf, despite decreased residual control compared to penetrant fungicides. Many of the alternative products do not have the same broad spectrum of activity.
Unfortunately, cultural management may not be sufficient to protect turf in stressful conditions, especially when weather conditions are conducive to the development of a particular disease, and in particular on golf greens and tees. In a good IPM program, no fungicide application should be considered for a specific disease problem without considering secondary problems. Before it is determined that use of an alternative to chlorothalonil will be a sound decision, it is necessary to consider all disease problems in an area and in a particular season. Often, determining a viable alternative is a complex task involving more than a single disease evaluation. At this time, there is no viable alternative to chlorothalonil plus a penetrant fungicide for control of anthracnose on putting greens. See Figure 5 for special considerations about the application of chlorothalonil for anthracnose in Massachusetts.
Figure 5. Guidelines for the use of chlorothalonil for anthracnose on putting greens in Massachusetts.
Triticonazole (Trinity, Triton) provides good control of a number of turf diseases including anthracnose, dollar spot, necrotic ring spot, red thread, brown patch, and take-all patch. Triticonazole is one of the demethylation inhibitor (DMI) fungicides. If you make a decision to use triticonazole, but are located in a Zone II or IWPA area, several alternatives in the DMI class are available. Alternatives include propiconazole, fenarimol, metconazole, triadimefon, and myclobutanil. Refer to Table 22 in the Disease Management with Fungicides section of this guide for additional information.
Dinotefuran (Zylam) is one of several insecticide compounds in the neonicotinoid class. While it is used more commonly in landscape settings, it is now being marketed for control of annual bluegrass weevils on golf courses. If you wish to control ABW in a Zone II or IWPA area, there are several alternatives to dinotefuran. These include a pyrethroid to target adults; or indoxacarb, spinosad, chlorantraniliprole, or trichlorfon to target larvae.
Thiamethoxam (Meridian) is another insecticide in the neonicotinoid class. Insects on the label include annual bluegrass weevil, black turfgrass ataenius, caterpillars, billbugs, and white grubs. If you wish to make an application for any of these target insects in a Zone II or IWPA area, you should be able to substitute another neonicotinoid. For example, imidacloprid or chlothianidin are viable alternatives and are both somewhat less soluble than thiamethoxam. If the primary target is white grubs, chlorantraniliprole would also be an alternative. See the Insect Management with Insecticides section of this guide for additional information.
Fenamiphos (Nemacur) is a nematicide and is labeled for use on golf course greens (bentgrass) where virtually all nematode problems on turf occur. Fenamiphos has been gradually phased out of the turf market, but any existing stocks can still be used until October 6, 2017. As such, fenamiphos is a highly toxic material and should be used only after high nematode populations have been confirmed by a diagnostic lab (for the UMass Extension Plant Diagnostic Lab, see ag.umass.edu/services/plant-diagnostics-laboratory).
Considerable testing underway at this time seeks to identify viable alternatives to fenamiphos, but an effective replacement has yet to be found. Cultural practices that encourage root system health and development are strongly recommended as a first line of defense against nematode pressure. Cultural management may help to mitigate damage from low nematode populations, but unfortunately may not be sufficient for golf greens with high populations.