Followup Inspection by Masaya Mayeda
Anacostia Watershed Society

Sewer Leakage into NW Branch

From physical/chemical analysis data (See table down below), it seems like the impact on the stream is minor since the leak is stopped on emergency basis. There are not so many coliforms in the stream anymore. Because the pipe looks vulnerable, we need to keep an eye on it.

Date Station Name NH4-N
(mg/L)		 Surfactants
(mg-LAS/L)		 Potassium
(mg/L)		 (NH4-N)/K
ratio		 pH w. temp
(° C)		 DO
(mg/L)		 Conductivity
(µS/cm)		 fecal
coliform
(cfu/ 100ml)		 E coli
(MPN/ 100ml)
11/10 NW-BC1-TU
(upstream of the site)		 0.09 0.3 4.3 0.02 7.49 7.9 10.78 259 50 20
11/10 NW-BC1-TD
(downstream of the site)		 0.07 0 3.9 0.02 7.22 9.2 8.58 254 300 100

A minor leak from the sewer pipe is possible.
The sewer pipe has cracks although leaking may be minor.

GPS coordinates Latitude: 39.02776 Longitude: -76.99925

GPS map for the site (The site was named as NW-BC1 for this map)

Cover picture

Photo 1: with a shoe to show the scale

Photo 2

Photo 3: A crack at the joint.

Photo 4: another crack in the pipe