A stand-up paddler and a two-person outrigger canoe on the Hudson on a calm morning

What about the water itself?

Everyone asks, and it is a fair question. The Hudson has come a long way, and it still has days when you should keep out of it.

After the rain
The one rule

After heavy rain, stay off the river.

Rain washes sewage and street runoff into the Hudson, and germ levels can stay above swimming guidelines for days after a storm.

Pick how hard it rained and how long ago it stopped. The tool shows the general pattern river groups describe. It does not measure the water and cannot tell you what is in it today.

Illustrative shape only. Real water quality depends on the storm, the tide, the outfall and the day, and this graph is not a measurement.

Three things to know
  1. Rain is the trigger. Hoboken's old sewers share pipes with the storm drains, so heavy rain can overflow into the river.
  2. Give it days, not hours. Riverkeeper advises avoiding contact after heavy rain, and levels can stay high well after the sky clears.
  3. Check before you go. The NHSA outfall map and recent sampling results tell you more than how the water looks.
A word of cautionBefore and after any session.
  • Skip the water after heavy rain, and give it a few days. Pathogens can stay elevated well after the sky clears.
  • Check the NHSA Waterbody Advisory map before you go, and stay well away from any outfall that is red, at least 100 feet.
  • Look at recent sampling results from Riverkeeper or other community programs for the area.
  • If you see or smell sewage, floating debris or a sheen, do not go in or on the water.
  • Cover cuts and scrapes with waterproof dressing, and keep your head and face out of the water as much as you can.
  • Do not swallow river water. Rinse off afterward, wash your hands before you eat, and wash your gear.
  • If you feel sick in the days after, such as stomach upset, fever, or a skin or ear infection, tell a doctor you were on the river.

General guidance, not medical or legal advice.

Where to look

Check the water, and go with people who know it.

Hoboken Cove Community Boathouse, Ke Aloha Outrigger and Resilience all run programs at the Hoboken waterfront. Ask them about schedules and how they handle rain and water quality.

Independent organizations, not part of Hoboken Surf Club. Links are for education and may change. General guidance, not medical or legal advice.

Learn more

Where the problem comes from.

Old pipes, one set of drains

In older cities like Hoboken, one network of pipes carries both household sewage and street runoff. On a dry day that all goes to a treatment plant. In a heavy rain the pipes fill faster than the plant can take the flow, and the extra is released into the river through outfalls. These releases are called combined sewer overflows, or CSOs, and what comes out is minimally treated sewage mixed with stormwater.

North Hudson Sewerage Authority (NHSA) runs the outfalls along this stretch of the river, from West New York south to Hoboken. Each one is marked with a sign and an identification number.

This is also where the tide matters. The river runs both ways, so water from an outfall can be carried upriver on the flood and back down on the ebb, past the same shoreline more than once.

Sewage bacteria are the main concern for people on the water, because swallowing or touching contaminated water can make you sick. Scientists measure them with an indicator organism called enterococcus. Finding it in a sample is a signal that sewage may be in the water.

Cleaner than it used to be, and still being worked on

Here is what the local sewer authority has published about its own effort. Check the sources for current numbers, because projects and counts change.

  • Fewer outfalls

    NHSA reports that it has eliminated three of its twelve historic outfalls, leaving nine active in its 2019 newsletter.

  • Pipes and tanks

    NHSA reports relining more than 5.5 miles of sewers and building detention tanks under parks, so some storm flow is held and sent for treatment later.

  • Green infrastructure

    Rain gardens, permeable surfaces and similar projects keep stormwater out of the pipes in the first place.

  • Long-term plan

    In 2015, NJDEP required every combined sewer system in New Jersey to develop a Long-Term CSO Control Plan. NHSA reports about $65 million invested so far.

  • Real-time advisories

    NHSA's Waterbody Advisory System uses sensors in the sewer system and shows each outfall on a map. Red means an overflow is happening and contact within 100 feet of that outfall should be avoided.

  • Independent testing

    Riverkeeper and community volunteers sample the Hudson for sewage-indicating bacteria and publish the results, so the public can see the water for themselves.

Figures come from NHSA's 2019 CSO newsletter and Waterbody Advisory page. They are the authority's own numbers and may be out of date.

What the numbers mean

If you look at sampling results, you will see counts of enterococcus per 100 milliliters of water. The EPA's 2012 recreational water quality criteria give two reference values for enterococcus, and either set may be used.

35
typical 30-day average (geometric mean), CFU per 100 mL
130
level a single sample should rarely exceed (statistical threshold value), CFU per 100 mL

The alternate set is 30 and 110. These are criteria for protecting public health at swimming beaches, and a river sample close to an outfall can be far above them after rain. A single result is a snapshot of one spot at one hour, and conditions can change within hours as rain, tide and overflows come and go.

Where next

How the river flowsFerry and boat waves