New Jersey / Reports /

Cyanobacteria advisory (harmful blue-green algae) reported, Aug 25, 2026

Advisory active · 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 01badc00-322a-4042-ada9-85023b966669, updated by the source Aug 29, 2026, 8:00 AM 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: 40.92291, -74.65232; 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: “Lake Hopatcong”. DirtyWaterWatch links this report to Lake Hopatcong, NJ. Match basis: the water named in the report.

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

Aug 25, 2026, 10:09 AM EDT

Ended

not reported

Detail provided by the source

Times known to the minute

Reported to the source

not given

Published

not given

Source last updated

Aug 29, 2026, 8:00 AM 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 active

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 Lake Hopatcong: Official advisory in effect, Aug 25, 2026, 10:09 AM EDT to Sep 12, 2026, 8:00 AM EDT
• No current status shown Lake Hopatcong: Advisory not re-confirmed by its source recently, Sep 12, 2026, 8:00 AM EDT to Nov 23, 2026, 9:09 AM EST

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

01badc00-322a-4042-ada9-85023b966669

Original notice

Read the original notice

Earlier version

None: this is the first record

Later versions

None

{
  "waterbody": "Lake Hopatcong",
  "site_id": "NJLM-0018-8",
  "municipality": "Hopatcong Borough",
  "county": "Sussex",
  "bathing_beach": "NA",
  "visits": [
    {
      "objectid": 2779,
      "sitevisitdate": "2026-08-25T10:09:00-04:00",
      "siteid": "NJLM-0018-8",
      "advisorytier": "Watch",
      "advistorytrigdt": "2026-08-29T08:00:00-04:00",
      "algaeobserved": "No",
      "cellct": 26250,
      "microcystins": null,
      "cylindrospermopsin": null,
      "anatoxin": null,
      "saxitoxin": null,
      "predomtaxa": "Phormidium",
      "toxinpresent": null,
      "comments": null,
      "EditDate": "2026-08-27T11:39:33-04:00"
    }
  ],
  "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)"
}