Delaware Estuary Water Quality Monitoring Program
Introduction

Initiated in 1967, DRBC's Delaware Estuary Water Quality Monitoring Program (aka the Boat Run) is one of the longest running monitoring programs in the world.

Each year, DRBC contracts with the Delaware Dept. of Natural Resources and Environmental Control to collect surface water samples in the Delaware Estuary, from the head of tide at Trenton, N.J. to the mouth of the Delaware Bay.

Samples are collected at 22 stations to manage water quality and ensure that criteria are being met.

This monitoring program provides accurate, precise and defensible estimates of the surface water quality of the Delaware Estuary and allows assessment of water quality criteria compliance. 

Sample analysis includes routine and bacterial parameters, nutrients, dissolved oxygen, heavy metals, chlorophyll‐a, dissolved silica and volatile organics.

In 2020, DRBC added 1,4-Dioxane to the list of parameters sampled.

Bacterial sampling results for fecal coliform and enterrococcus are posted below.

Other data are inputted into the U.S. EPA's Water Quality Portal, which is available to the public.

Map of Sampling Locations:

Map of the Monitoring Sites for the Delaware Estuary Boat Run.

View map on ArcGIS

View map as pdf

View Map of Delaware Estuary Water Quality Zones (pdf)

View DRBC River Mileage System

Delaware Estuary Water Quality Monitoring Program: Bacterial Data

Typically, once monthly from April to October, bacteria samples are collected at the 22 stations. Fecal coliform and enterococcus bacterial data (unit of measurement is cfu/100mL) are used to determine compliance with the commission's water quality standards for recreational use. Learn more.

DRBC's bacterial water quality criteria standards are based upon the average of several samples over a period of time. While individual samples taken on a single day such as those reported here may exceed the number listed under the standard column, the standard is not violated until the average of multiple samples within a Water Quality Management Zone exceeds the standard value. Bacterial data are highly variable, and individual sample exceedances commonly occur following rainfall events due to non-point source runoff and discharges from combined sewer overflows.

Most Recent Bacterial Sampling Data:

Sampling
Site
River
Mile

6/14/21 Enterococcus

Enterococcus
Std.

6/14/21
Fecal Coliform

Fecal
Coliform
Std.

Trenton
131.04
11
33
400
200
Florence
122.4
10
33
130
200
Burlington
Bristol Br.
117.8
30
33
150
200
Torresdale
110.7
58
33
190
200
Betsy Ross Br.
104.75
34
88
280
770
Benjamin
Franklin Br.
100.2
10
88
160
770
Navy Yard
93.2
6
88
120
770
Paulsboro
87.9
4
88
60
770
Eddystone
84.0
2
88
47
770
Marcus Hook
78.1
4
35
130
200
Oldmans Pt.
74.9
1
35
120
200
Cherry Island
71
6
35
110
200
New Castle
66.0
17
35
460
200
Pea Patch Is.
60.6
11
35
97
200
Reedy Island
54.9
10
35
77
200
Liston Pt.
48.2
6
35
470
200
Smyrna River
44.0
4
35
77
200
Ship John Light
36.6
3
35
8
200
Mahon River
31.0
1
35
ND
200
Elbow of
Crossledge
Shoal
22.75
1
35
1
200
South of Joe
Flogger
Shoal
16.5
ND
35
ND
200
South Brown
Shoal
6.5
ND
35
ND
200

If results are flagged with the indicator "QC," the calculated precision between the analytical and duplicate results is outside the quality control limit for this test. For additional details, contact John.Yagecic@drbc.gov.

n/a = data not available
ND = non-detect

View March 16, 2021 data (pdf)

View April 19, 2021 data (pdf)

View May 25, 2021 data (pdf)

Delaware Estuary Water Quality Monitoring Program (Boat Run) Data Explorer

DRBC staff developed an interactive application that allows the user to explore water quality data collected from the DRBC Delaware Estuary Water Quality Monitoring Program (aka the Boat Run) from 1999-2016.

Delaware Estuary Water Quality Monitoring Program (Boat Run) Data Explorer (click for details)