Case Studies

What Can Sewer Sentry Do For You?

See all the ways our combined sewer overflow solution is saving municipalities money and solving longtime problems.

Case Studies

case study: 80% Rainwater Inflow Reduction in Richwood, LA by Smart Cover Systems

From April 29, 2024 through July 22, 2024, Smart Cover devices were installed on different manholes in Richwood, Louisiana to measure the amount of rainwater inflow into a manhole during a rain event and the amount of time it took for the associated levels to return to normal. On each manhole measured, the data was collected before and after the Sewer Sentry was installed.

NOTE: These measurements are based on replacing 106 ring and covers with CAP Sewer Sentry.

Two-minute explanation of rainwater inflow using red dye

Play Video about Rainwater Inflow
Play Video

Two-minute demonstration of the Sewer Sentry in action

View the individual results of each manhole here

case study: 98% Reduction Measured by Lousiana Tech University's Trenchless Technology Center

Background

The Trenchless Technology Center (TTC) at Louisiana Tech University was contacted by CAP (Composite Access Products) to perform testing for a comparison of its 24” and 30” composite polymeric manhole lid versus a typical cast iron manhole lid for inflow leakage. The AS3996 testing procedure provided to the TTC was used to carry out the leakage testing. The setups and results and described below.

LEAK TESTING

The Trenchless Technology Center (TTC) at Louisiana Tech University was contacted by CAP (Composite Access Products) to perform testing for a comparison of its 24” and 30” composite polymeric manhole lid versus a typical cast iron manhole lid for inflow leakage. The AS3996 testing procedure provided to the TTC was used to carry out the leakage testing. The setups and results and described below.
Leak Test

The table below represents the total leakage over a 10 minute period for both size manholes.

Table 1: Flow Rate Data

Table Chart 1
The table confirms that there was no leaking from the manhole when the AS3996 testing procedure was followed.

Table 2: Flow Rate Data (Bolts Removed)

Table Chart 2
A secondary leak test was performed out of curiosity. The same procedure was followed with a set number of bolts removed in each test. It should be noted that the dirt shield covers were not covering the holes of the bolts that had been removed.

CONCLUSION AND CERTIFICATION

The leak testing done at the TTC showed the CAP system performed much better than a typical cast-iron manhole lid even without bolts. The 24-inch CAP lid only leaked between 1-2.5 GPM with all four bolts removed, and the 30-inch CAP lid only leaked between 1-5 GPM with all four bolts removed. The cast iron lid leaked approximately 45 gallons per minute.

case study: West Ouachita Sewer District #5

The Sewer Sentry device stops storm water from going through hole in the manhole cover simply by creating a new point of entry ―a “raised hole”―that is 5/8” higher than the surface of the manhole. At the same time, it reduces sewer gas problems, by allowing enough oxygen to reach the sewer.

ELECTRICAL COST

$ 18000

Per YEAR

Comparing kilowatt usage of pump stations before and after Sewer Sentries show an average of 25% reduction in electricity bills for an entire year.

TREATMENT COST

$ 80000

PER MONTH

Treatment cost has gone down during rainy months on average $10,000 per month with only 1600 out of 3000 manholes equipped with the Sewer Sentry.

PROPERTY FLOODING

3

PER YEAR

Flooding of homes and businesses due to rainstorms has gone from 3 a year down to 0.

REPORT OF Sanitary Sewer Overflows (SSO's)

Traditional
40
With Sewer Sentry
0

Report of SSOs due to rainstorms in the first Quarter of the year have gone from 40 down to 1.

PER YEAR
8

Complaints about the smell of pump stations has gone from 8 per year down to 0.

Kilowatt Usage Comparison

Year 2013 52.6″ Rainfall
Year 2015 56.9″ Rainfall

4.3" of Additional Rainfall

Without Sewer Sentry

0 %

Avg. Increase

Without Sewer Sentry

0 %

Avg. Increase

With Sewer Sentry

0 %

Avg. Decrease