New Jersey / Reports /

Cyanobacteria advisory (harmful blue-green algae) reported, Jul 20, 2026

Advisory lifted · NJDEP Harmful Algal Bloom Program (Division of Water Monitoring, Standards and Pesticide Control)

Source: NJDEP Harmful Algal Bloom Program (Division of Water Monitoring, Standards and Pesticide Control), record 39b5c4ee-1fa8-47f9-9447-77ae92d89172, updated by the source Jul 25, 2026, 12:00 PM EDT, retrieved 2026-11-02 21:19 UTC · Read the original notice

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1. Reported wastewater outlet

Operator named in the record: not named. Outlet: not stated. Location: 40.37008, -74.62222; location source: given in the source record.

Outfall: a pipe or outlet where wastewater enters a water body.

2. Waters named in the notice

The notice names: “Carnegie Lake”. DirtyWaterWatch links this report to Delaware and Raritan Canal, NJ. Match basis: the report's location, matched to the nearest tracked water.

3. Estimated downstream stretch

We estimate routes only on rivers before they become tidal. We do not estimate routes through tidal water or lakes.

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When it happened and when it was reported

Event and notice times use Eastern Time (EST or EDT). Retrieval times use Coordinated Universal Time (UTC).

Started

Jul 20, 2026, 8:39 AM EDT

Ended

Oct 30, 2026, 8:00 AM EDT

Detail provided by the source

Times known to the minute

Reported to the source

not given

Published

not given

Source last updated

Jul 25, 2026, 12:00 PM EDT

Last retrieved by DirtyWaterWatch

2026-11-02 21:19 UTC

What and how much

Type

Cyanobacteria (harmful blue-green algae) can make water unfit for contact; the issuing authority decides when its advisory ends.

Status in the record

Advisory lifted

Material

not stated

Volume

volume not reported (not stated whether estimated or measured)

Volume as reported

none

Advice from NJDEP Harmful Algal Bloom Program (Division of Water Monitoring, Standards and Pesticide Control)

“NJDEP HAB alert tier at this site: Watch.”

Advice period

This report does not state a period. See the rule DirtyWaterWatch applies and its source.

Basis

NJDEP HAB Dashboard: the current alert at a site is its latest sample's tier (HAB Watch, Advisory, Warning, Danger); no fixed window

Status history from this report

• Discharge or advisory reported a water not yet on the map: Official advisory in effect, Jul 20, 2026, 8:39 AM EDT to Oct 30, 2026, 8:00 AM EDT

Source: DirtyWaterWatch calculations using this report and the published status rules. Updated 2026-11-02 21:26 UTC.

Source and versions

Source

Division of Water Monitoring, Standards and Pesticide Control

Source record number

39b5c4ee-1fa8-47f9-9447-77ae92d89172

Original notice

Read the original notice

Earlier version

None: this is the first record

Later versions

None

{
  "waterbody": "Carnegie Lake",
  "site_id": "CARN",
  "municipality": "Princeton",
  "county": "Mercer",
  "bathing_beach": "NA",
  "visits": [
    {
      "objectid": 2573,
      "sitevisitdate": "2026-07-20T08:39:00-04:00",
      "siteid": "CARN",
      "advisorytier": "Watch",
      "advistorytrigdt": "2026-07-25T12:00:00-04:00",
      "algaeobserved": "No",
      "cellct": 33500,
      "microcystins": 0.296,
      "cylindrospermopsin": null,
      "anatoxin": null,
      "saxitoxin": null,
      "predomtaxa": "Merismopedia",
      "toxinpresent": null,
      "comments": "Turbid ",
      "EditDate": "2026-08-27T08:43:51-04:00"
    },
    {
      "objectid": 2925,
      "sitevisitdate": "2026-10-28T12:07:00-04:00",
      "siteid": "CARN",
      "advisorytier": "HAB Not Present",
      "advistorytrigdt": "2026-10-30T08:00:00-04:00",
      "algaeobserved": "No",
      "cellct": 0,
      "microcystins": null,
      "cylindrospermopsin": null,
      "anatoxin": null,
      "saxitoxin": null,
      "predomtaxa": null,
      "toxinpresent": null,
      "comments": null,
      "EditDate": "2026-10-29T14:21:00-04:00"
    }
  ],
  "credit": "NJDEP HAB Dashboard (provided for information purposes only; not monitored 24/7)",
  "current_tier": "Watch",
  "highest_tier": "Watch",
  "last_confirmed_basis": "advistorytrigdt (the date the tier was set)",
  "ended_at_basis": "'HAB Not Present' sample at this site: advistorytrigdt (the date the tier was set)"
}