Stormwater Management

rain-umbrellaThe Problem

We all see the water flowing into our storm drains during a storm or snowmelt. What most residents don’t realize, is that the water flowing into our Municipal Separate Storm Sewer Systems (MS4’s) is arriving dirtier and in greater quantities than ever before.

The problem occurs when precipitation lands on an impervious surface such as a paved street, rooftop, or driveway. Instead of the water slowly soaking into the soil and becoming purified, the water flows over these impervious surfaces and picks up pollutants. Oil and grease from roadways, pesticides from lawns, sediment from construction sites, and litter are all picked up by the water and conveyed directly to a storm drain with the impurities in tow.

A Practical Example – Rain Water Collection Activity

Fact: 1″ of rainfall on a 1000 sq. ft. roof will produce 600 gallons of rainwater. To calculate the square footage of your house, you can measure the outside area of the exterior walls. To find area, multiply Length times Width. Using an example of a house that is 50′ in length by 35′ in width, we would multiply 50′ x 35′ to equal 1750 sq. ft. Move the decimal point over 3 places to the left to continue the equation.

Since 1″ of rain yields 600 gallons on a 1000 sq. ft. roof, we will multiply 600 x 1.75 to determine the quantity of run-off from our example roof. 600 x 1.75 = 1050 gallons.For every one inch of rainfall, then, approximately 1050 gallons will drain off of the roof.To determine an annual rooftop yield for a 1000 sq. ft. roof in Malvern Borough, we take the average rainfall, determined to be 41.20 ” according to, and multiply by 600 gallons. 41.20 x 600 = 24,720 gallons of rainfall.

How much rainwater can be collected from your roof?

rains-drainsThe Result

  • Increased volumes of polluted water reaching our storm      sewers impair the waterways, thereby discouraging use of the resource.
  • Pollutants contaminate drinking water supplies, and      interfere with the habitat for fish, aquatic organisms, and wildlife.
  • High volumes of water undercut streambeds and cause      erosion, leading to an overall downfall in the health of a stream.

The Solution

Malvern Borough is part of a statewide campaign to combat storm sewer pollution. The Pennsylvania Department for Environmental Protection has developed the following six guidelines (Minimum Control Measures) for program development in order to help communities like Malvern Borough maintain a complete stormwater program. Please click below for the EPA requirements and further explanations:

Public Education and Outreach

Distributing educational materials and performing outreach to inform citizens about the impacts polluted storm water runoff discharges can have on water quality.

Controls include: Creating brochures or fact sheets for public distribution.

Instituting educational programs for school-age children.

An Exercise – Take the Stormwater Challenge

[click on the link above to open a crossword placemat!]

Public Participation/Involvement

Providing opportunities for citizens to participate directly in program development and implementation.

Controls include: Organization of community clean-ups, storm drain stenciling, outfall monitoring, and citizen watch groups.

Illicit Discharge Detection and Elimination

Developing a system to detect and eliminate illicit discharges to the storm sewer system.

Controls include: Promoting recycling programs for commonly dumped wastes.

Locating and testing suspected problem areas for pollution. Informing the public of the hazards of illegal discharges.

Construction Site Runoff Control

Developing, implementing, and enforcing an erosion and sediment control program for construction activities.

Controls include: Appropriate site plan review and inspection of new construction.

Require implementation of State and County erosion control regulations.

Post Construction Runoff Control

Creating a program to address storm water runoff from newly developed or redeveloped areas.

Controls include: Require protection of environmentally sensitive areas (e.g. wetlands).

Require recharge of runoff from new impervious surfaces.

Pollution Prevention/Good Housekeeping

This program’s goal is to reduce pollutant runoff from municipal operations.

Controls include: Regular street sweeping. Reduction in the use of pesticides or street salt. Frequent catch-basin cleaning.

no dumpingStorm Drain Stenciling

Malvern Borough with the assistance of volunteers has started to mark some of the storm drains in the Borough with the “No Dumping / Drains to Waterways” stencils. These storm

drain stencils educate the public that anything you dump into the storm drain ends up directly in a creek or other public waterway. If you would like volunteer and help with storm drain stenciling: please call the Borough at 610-644-2602 or e-mail us at

downthe drainWhat Residents can help watch for:

  • Sediment leaving a construction site in stormwater
  • Spills, hazardous materials(Chemical, Gas, Oil)
  • Illegal dumping activity into streams or storm sewers
  • Dry weather flows observed to be contaminated or polluted from outfall pipes into streams (72 hours after a rain storm)
  • Observed pollution event or pollutants in stream
  • Clogged, leaking or overflowing sanitary sewer lines
  • Inadequately treated effluent from a sewage treatment plant

Citizen Awareness Needed to Report Water Pollution

Citizens are encouraged to be on the lookout for illicit (illegal) discharges to our creeks and encouraged to call 911 or the “Hotline” numbers below to report them.  Remember all of our storm drains lead to creeks, and there should be only rain going into these drains.

Over the past four months, residents in our  watersheds  have reported the following illicit discharges and practices which can foul our creeks and drinking water:  leaking sanitary sewer manhole covers (especially during dry weather), soapy  or power washing water entering storm drains, strong sewage odors , odors of gasoline,  swimming pool discharges into streets, broken water mains, drainage of sump pumps directly into creeks, dumping of trash and yard waste near creeks, running hoses into creeks or storm drains, and fish kills, by calling these numbers.  Please save them for future reference.  Your efforts are key to protecting  clean water!

Borough of Malvern – Citizen Water Quality Hotlines

Issue Observed Primary Contact Info Additional Info

DEP Water Quality Complaint Hotline – Daytime

484-250-5991 Weekdays: 8:30 AM to 4:30 PM

DEP 24-Hour Water Quality Hotline

484-250-5900 Anytime, including evenings & weekends

Spills and other Emergencies Hotline

484-250-5900 PA Emergency Mgmt Agency: 800-424-7362

Off site discharge of sediment

CHESCO Conservation Dist.: 610-925-4920 Send photo, full address, & directions

CLOGGED or LEAKING, sanitary SEWER LINES; sewage smell in creek

Malvern Borough: 610-644-2602 Weekdays, 9 AM – 12 noon; 1 PM – 5 PM. After hours, call 911

Fish kills, illegal fishing

PA Fish Commission: 1-855-FISHKILL For fish kills also call 484-250-5991

Broken water mains

AQUA PA: 610-525-1402 Twenty-four hour

 Broken Water Mains

Chester County Water Authority 610-876-8181 24 Hour Line


Sanitary Sewer Backup

In the event of a sanitary sewer backup at your property, please call the Borough  office first.  The administration office hours are 9:00 am to 12:00 noon and 1:00 pm to 5:00 pm.  Monday through Friday.  After those hours, call 911 and a township highway crew will be dispatched to check the line.  Although the Township conscientiously maintains its sewer system, periodic backups into homes or businesses inevitably occur.  In most cases, the Borough’s responsibility ends when the line is cleared and the problem causing the blockage has been addressed.  Responsibility for cleanup and damage to the premises rests with the resident.  The Borough will not reimburse a property owner for plumbing fees.  Most homeowners insurance policies have optional riders for sewer backups that, if purchased, will provide coverage.    -

Updated June 19, 2013  CRC Watersheds Association.