Malvern Borough Stormwater Management Program
In Conjunction with the Pennsylvania DEP MS-4 Program

The 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 weather.com, and multiply by 600 gallons. 41.20 x 600 = 24,720 gallons of rainfall.
How much rainwater can be collected from your roof?
The 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:
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 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.
Storm 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 malvern@malvern.org
What 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
Residents may be the first to recognize "illicit" discharges dumping into storm sewers or coming out of from storm sewer outfalls. If you see an "illicit" discharge please report that to the Borough by one of the following methods:
Issues Observed |
Primary Contact Info. |
Additional Contact Info. |
DEP Water Quality Complaint Hotline – Daytime |
484-250-5991 or 5970 |
Weekdays 8:00 AM to 4:30 PM |
DEP 24-Hour Water Quality Hotline |
484-250-5900 or 866-255-5158 |
Anytime, including evenings and weekends |
Spills and other Emergencies Hotline |
PA DEP 484-250-5900 |
PA Emergency Mgt. Agency 800-424-7362 |
Off site discharge of sediment |
Chester Co. Conservation District 610-925-4920 |
Send photo, full address, and directions |
Clogged, leaking, overflowing sewer lines |
Malvern Borough 610-644-2602 |
After hours call Chester Co. Dept. of Emergency Services 610-692-5100; if sewage is entering water courses, also call DEP |
Dry weather storm sewer flows that are observed to be polluted or contaminated |
Malvern Borough 610-644-2602 |
Weekdays during working hours |
Fish kills, illegal fishing |
PA Fish & Boat Commission 717-626-0228 |
For fish kills, also call DEP 484-250-5991 or 5900 |
Broken water mains |
AQUA PA 610-525-1402 |
24 hour |
Related Publications and Resources
Please visit the 'Documents' and 'Links' Pages on the Storm-Water Management Page-set for additional information, publications and resources.