County Investigates Mosquito Problem; Issues Report

by Cindy Goldstein -

After receiving an email dated July 22, 2026, from 118 Shore Acres and area neighbors requesting that Westchester County intervene in the ongoing mosquito challenge (see HERE), a two-person team was dispatched to the area on July 27^th for a two-day inspection.  The formal report of their findings was dated August 4, 2026, and is available HERE.

High Mosquito Activity in Area

That report describes extremely high mosquito activity in several locations: Otter Creek Preserve, Otter Creek, the Tributary to Guion Creek and Magid Pond.  Editor’s Note: the report misspells Magid Pond.  The mosquitoes were so dense that in some locations the inspectors had to retreat to their vehicle and continue the inspection from roadways.

In addition to inspecting for mosquitoes, the field work included collecting surface water samples that are currently being analyzed.

Neighbor Requests

The email from the residents asked for three things: 1) an immediate inspection of Otter Creek Preserve, Guion Creek perimeter areas, and stormwater catch basins and document current risk level, 2) a formal public health nuisance determination under Public Health Law Section 1305, and 3) an order to the Village of Mamaroneck to fund and implement abatement.

Call With the Deputy Commissioner

In a conversation with the Deputy Commissioner of the Department of Health (DOH), Chris Ericson, on August 4, The Mamaroneck Observer learned the following information:

1)     Ericson described the inspectors’ field work and explained that no mosquito samples were collected or tested. The DOH has mosquito traps throughout the County but none in Mamaroneck.  These traps are monitored to see which mosquito species are in the area.  Samples from those traps are sent to the NYS lab in Albany and tested for various diseases.  One mosquito in Westchester has tested positive for West Nile Virus so far this year.  Editor’s Clarification: Since this article was written, Westchester County has just reported that the first batch of mosquitoes collected in Rye has tested positive for West Nile Virus.  See HERE for the notice and tips to avoid the virus.

2)     West Nile Virus and other transmissible diseases must be reported by doctors and hospitals to the County Board of Health when they encounter patients with them.  When discovered, the Department of Health follows up with the patient to determine where they might have picked up the disease.

3)     According to Ericson, there are currently no positive cases of West Nile Virus in humans in Westchester.  He explained that those transmissions generally happen later in the summer and early fall and that, on average, there are 6 cases annually County-wide. 

4)     If the number of mosquitoes is high enough to be determined a public nuisance, Ericson explained that notices of violation to rectify the property would be issued.  It appears from the conversation that several notices were to be issued in the Village to public and private property owners.  The notices will be mailed and hand-delivered to the property owners, and a reasonable time to mitigate would be extended.  The exact method of remediation is left up to the property owner.  If the owner does not mitigate the property, the next step would be a summons to appear before a DOH administrative law judge.  Editor’s Clarification: Since this article was written, four property owners received notices – see below.

5)     Ericson confirmed that the Westchester County Department of Health is responsible for enforcing all public health and sanitary code regulations across the county.  There are no individual municipal “Boards of Health” across the county that may enforce these regulations.

6)     When asked who pays for the remediation and if the Village was responsible for mitigation on private property, Ericson said: “It doesn’t work like that.”  He explained that a nuisance on private property is the responsibility of the owner.

What the Report Found

The two-day field inspection report identified significant issues in the area of Magid Pond (a privately owned large stagnant pond), Otter Creek and Preserve areas, and Guion Creek.  Dense stands of Phragmites australis, an invasive species, contribute to the explosion of mosquitoes because they create mosquito habitat in wetlands and contribute to stagnant water, reduced wind movement, and limited predator access.  Long-time residents describe the stands of Phragmites as spreading over time and covering more territory.

Notices to Property Owners

Four property owners must remediate their property to combat mosquitoes.  They are:

The Village of Mamaroneck for catch basins and Guion Creek, the owner of Magid Pond, Westchester Land Trust, and the Town of Rye.  See Village Order HERE.

The Village reported the following remediation work has either been done or will be completed by August 7th: Clarification added below at 3:00 pm August 7th:

1)    Treated 127 catch basins (larvicide DEC permit received) in and around Shores Acres and Taylor's Lane neighborhoods

2)    Spraying the median along The Parkway

3)    Spraying Village property along Taylors Lane and on Shore Acres Drive at Guion Creek Preserve

4)    Placed larvicide dunks in 150 catch basins in other areas of the Village including Rye Neck, Heathcote Hill, Harbor Heights and Orienta with a promise of more to come

The contractor is using a botanical insecticide (EVO VIA MT) according to Village Manager Kathleen Gill.  See HERE.

This report is helpful as it identifies areas that were not previously identified, such as Magid Pond, and it sets a two-week timeframe by which property owners must take action to remedy the situation or face fines of up to $1,000 per day.  Meanwhile, the residents in the surrounding areas are still affected by the large numbers of mosquitoes, but help is on the way.