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The Riverside handbook

Living in Riverside, NY: what to set up and who to call

Riverside has no town government of its own, so Suffolk County runs its elections and most services, and its children attend Riverhead Central School District. Peconic River Mobile Home Park reported one health-based violation to EPA in the last five years: a PFAS chemical (PFOS), beginning Jul 2024.

Riverside has no town government. It’s a census-designated place in Suffolk County, so the county and regional agencies provide most services. This page answers what we can; the same answers appear on Riverside’s town page under “Getting set up”.

I’m new in town

What to set up in Riverside, and who provides it. Tap an answer for the details and where they come from.

Home services

Power, water and internet

Who to call to start service at a new address in Riverside.

Electricity

Power comes from PSEG Long Island

PSEG Long Island (Long Island Power Authority), a state utility, serves all of Riverside. Its homes paid an average of 26.2¢ per kWh in 2025, about $195 a month (its average across New York, for customers on its standard service). New York lets you buy power from another supplier; 0% of PSEG Long Island’s home customers do, and PSEG Long Island still delivers it.

Service territory: HIFLD Electric Retail Service Territories (map dated Aug 2023). Prices and customers: EIA-861, 2025.

Drinking water · reported to EPA

Water comes from Peconic River Mobile Home Park

Peconic River Mobile Home Park supplies Riverside: about 50% of residents live in its service area. Calverton Hills Owners Association serves another 28%. About 24% of homes are outside any mapped community water system, most likely on private wells, which EPA doesn’t regulate. It draws ground water and serves 75 people in all.

1 health-based violation reported to EPA in the five years to October 2026: a PFAS chemical (PFOS), beginning Jul 2024. 78% of the 11,392 systems serving <=100 people had none.

Lead, 90th percentile3.0 ppb
015 ppb action level20

The latest lead result on file, the 90th percentile of homes sampled in Jan 2023–Dec 2025, was 3.0 ppb, below the 15 ppb action level that applied. That’s higher than 80% of similar systems’ latest results.

The system’s full record: EPA ECHO report

EPA SDWIS via Envirofacts (violations pulled Oct 9, 2026) and ECHO (lead samples, 2026Q3); service area: EPA Community Water System Service Area Boundaries v3.0 (EPA’s estimate). Violations are counted by the start of their compliance period. NY5101296.

Internet

2 home internet providers serve Riverside

86% of 894 addresses can get 100/20 Mbps; 49% can get fiber.

ProviderTechnologyAddressesFastest (Mbps)
OptimumCable, Fiber93%8,000/8,000
VerizonFixed wireless77%300/20

FCC National Broadband Map, as of December 2025. Availability as providers report it, not speeds people get.

Trash & recycling

We don’t have Riverside’s trash rules yet

Pickup rules, the dump and recycling in Riverside.

Trash, recycling and bulk pickupNot on fileRiverside has no town government of its own, so look for trash and recycling rules on the county’s site.
Schools

Where your child goes to school

Public school districts and the school path by grade.

Riverside kids go to
PK–44 elementary schoolsDepends on your address
6–8Riverhead Middle Schoolin Riverhead
9–12Riverhead Senior High Schoolin Riverhead

Riverside is in Riverhead Central School District.

Test scores and every school: see Schools →

U.S. Department of Education, NCES Common Core of Data, 2024–25. Enrollment rules and registration are the district’s.

Government & voting

No town hall: the county runs things

Riverside is unincorporated, so Suffolk County is the local government.

Local governmentSuffolk CountyRiverside is a census-designated place: no town hall of its ownCensus
Who runs elections hereSuffolk County Board of ElectionsElections here are run by Suffolk County (county election office). Yaphank Ave, P.O. Box 700, Yaphank, NY 11980 · (631) 852-4500FVAP, Sep 2024
Register to voteOnlineIn New York you can register online until 10 days before Election Day, in person until 10 days before Election Day, or by mail (postmarked 15 days before and received 10 days before).vote.govCheck your registration and polling placevoterlookup.elections.ny.govThe state’s voter lookup

Election office: FVAP local election office directory, updated Sep 2024; jurisdictions: EAC EAVS 2024. Registration rules and links: vote.gov, updated Aug 3, 2026.

ZIP codes & area codes

Riverside is in ZIP code 11901

ZIP codes where Riverside residents live, with the share of the town in each.

ZIPPost office nameShare of RiversideZIP’s residents in Riverside
11901Riverhead, NY100%9%

Census 2020 ZIP Code Tabulation Areas, by census block; post office names: GeoNames (CC BY 4.0). ZIPs created since 2020 are missing.

Everyday places

Getting around, the ER and the library

One line each; the subject pages have the rest.

ER: CMS hospital data. Library: IMLS Public Libraries Survey, FY2024.

Questions about living in Riverside

Who supplies Riverside’s drinking water, and has it had violations?

Peconic River Mobile Home Park (EPA ID NY5101296). It reported 1 health-based violation to EPA in the five years to October 2026: a PFAS chemical (PFOS). 78% of systems its size had none. Its latest lead 90th percentile was 3.0 ppb (Jan 2023–Dec 2025), against a 15 ppb action level.

Who provides electricity in Riverside?

PSEG Long Island (Long Island Power Authority), a state utility. Its homes paid about 26.2¢ per kWh in 2025 (EIA).

What internet providers serve Riverside?

Optimum, Verizon (FCC, as of December 2025).

What ZIP codes are in Riverside?

11901. Census 2020 ZIP Code Tabulation Areas.

What school district is Riverside in?

Riverhead Central School District.

How do I register to vote in Riverside?

In New York you can register online until 10 days before Election Day, in person until 10 days before Election Day, or by mail (postmarked 15 days before and received 10 days before). Elections here are run by the Suffolk County Board of Elections. Check your registration at voterlookup.elections.ny.gov.

Sources & dates

Every answer above names its source. Here they are with their dates.

  • Water: EPA SDWIS (Envirofacts, pulled Oct 9, 2026), ECHO SDWA 2026Q3, EPA CWS Service Area Boundaries v3.0.
  • Power: HIFLD Electric Retail Service Territories (map Aug 2023); EIA-861 final 2025.
  • Trash: OpenStreetMap, Geofabrik extract of Oct 9, 2026. © OpenStreetMap contributors (ODbL).
  • ZIP codes: Census 2020 ZCTA relationship files; GeoNames postal codes (CC BY 4.0).
  • Schools: NCES Common Core of Data, 2024–25.
  • Registration: vote.gov, updated Aug 3, 2026 (read Oct 10, 2026). Official sites and area codes: Wikidata.
  • Election office: FVAP local election office directory (fetched Oct 10, 2026; each record dated), EAC EAVS 2024 jurisdictions; registration and lookup links from vote.gov’s state data, checked Oct 10, 2026.
  • Internet: FCC National Broadband Map, as of December 2025.