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It's not like we have industrial waste spewing out of pipes into our ponds on Cape Cod, so where are the problems coming from? One of the biggests issues is too many nutrients (phosphorus is the biggest culprit in freshwater, whereas in saltwater, it's nitrogen). Nitrogen and phosphorus act like fertilizer and cause excessive growth of algae. This not only looks unpleasant, but also starves the water of oxygen when it dies. This can lead to fish kills and other problems. Some algae are even toxic to humans and pets. Other types of pollution can also harm aquatic life. Here are the top 5 sources of these unwelcome contributors to our ponds.
And before you get discouraged, suggested ways you can help fix or prevent these problems can be found here.
APCC's water sampling program
1. Septic Systems
Residential septic systems are the top contributor (80%) to the nutrient issue in both freshwater and saltwater. They were designed to remove bacteria, which they do effectively, but not to remove nutrients (it wasn't known this was a problem at the time). They leach both nitrogen and phosphorus into our sandy soils. Other types of soil that contain more iron can "bind" the phosphorous and keep it in the soil, but here it pretty much goes right through into the groundwater along with the nitrogen. That groundwater slowly flows through the ground and eventually reaches our ponds, where the nutrients in it fertilize the algae and cause it to overgrow. Everyone on Cape Cod contributes to this problem, as eventually all the groundwater reaches either freshwater ponds or our estuaries or salt ponds and the ocean.
2. Fertilizer, herbicide, and insecticide application
Not only are we dealing with the delayed results of historic application of these products, perhaps for agriculture, but people continue to use them in their own yards. The quest for a perfect green lawn in a place with sandy soils and hot, dry summers leads to the continued application of these products in an often vain attempt to make a yard look like storybook suburbia. While golf courses and other commercial lawns use fertilizers and pesticides, the vast majority is contributed by homeowners.
Fertilizer use makes up 10% of the total nitrogen load on Cape Cod. That may not sound like much, but it is totally controllable, and in light of the fact that we will be paying hundreds of millions of dollars to remove nitrogen by sewering and installing expensive new septic systems over the coming decades, does it really make sense to then keep adding more in?
And lawns require inputs of water, herbicides to keep "weeds" out, pesticides to kill any insects, and frequent mowing and leaf-blowing to maintain their perfect character. This result is a sterile wasteland, with no benefits to wildlife, and in fact removal of natural habitat and food sources for beneficial insects like pollinators*, and birds.
*Pollinators are insects like bees and butterflies, which pollinate our plants by flying from one to the other, picking up and depositing pollen along the way. Almost all of our food crops rely on pollinators, so killing them or destroying their habitats is bad.
3. Run-off
Run-off is rain water, snow melt or irrigation that flows from parking lots, roadways and roof tops. It collects pollutants such as bird and pet waste, oils, excess fertilizer and toxic chemicals from the land or air and impervious surfaces where there is no vegetation and transports them directly to storm drains, and in some cases our ponds.
Storm drains should operate by letting the sediment and other debris settle to the bottom of a large holding tank, and letting just the water flow from higher up the tank into perforated pipes, where it can slowly filter into the soil. But if drains are full of accumulated sediment, the outlet for the water will be clogged, or sediment will flow out with the water. In addition, some older drains just go directly into ponds with no settling feature. All of this results in two things: drains backing up during rainstorms causing flooding, and unfiltered runoff ending up in the ponds.
Falmouth's storm drains need to be cleaned out so they don't fill with sediment and debris and become useless. The town only has one machine and one crew to do this and there is a huge backlog. Many storm drains are filled to the brim, clogged with leaves and even have plants growing out of them! And that doesn't even address the old drains that do nothing to filter run-off before it ends up in the pond. These should be replaced.
Drains as they should look –minus the leaves (top right) – and when they are clogged (bottom right)
4. Atmospheric deposition
Pollution, in the form of particulates, heavy metals like mercury, or compounds like nitrous oxide – from factories, vehicle exhaust, wildfires etc. – is carried through the air by prevailing winds until it eventually falls to earth. Some of this ends up either in Cape Cod ponds, or on the land where rain can carry it into the ponds. Atmospheric deposition accounts for about 10% of the nitrogen in our waters.
5. "Contaminants of emerging concern"
Pharmaceuticals and Personal Care Products (PPCP's) are chemicals or mico-organisms that are not commonly monitored or regulated in the environment, but are suspected of having potentially adverse ecological and/or human health effects. They can include hormones, human and veterinary pharmaceuticals, and household products like soaps and lotions, insect repellents, perfumes and other fragrances, sunscreens, and hand sanitizers. In 2004, thirteen compounds were detected in low concentrations in some private and semi-public drinking water supplies on Cape Cod and three – an antibiotic, an antidepressant, and a solvent – were detected in the public water supply. The Massachusetts Environmental Trust has recently funded a study by Silent Spring Institute to sample and test public supplies for these emerging compounds.
6. Trash in the ponds
Old Ladies Against Underwater Garbage (OLAUG) is a group of 65-85 year-old women who swim in the freshwater ponds and collect the trash that's accumulated in them over the years. You wouldn't believe some of the things they've found: loads of golf balls and beer cans, toys and tires, but also a toilet and the front end of a '90s Corvette! And sadly, many whole or partial old docks made of pressure treated wood that – instead of disposing of it properly when they built a new one – the owners apparently just tossed into the pond and sunk. While the old ladies have a great time diving for trash, it is problematic in a number of ways. Many of these products are made using toxic materials, which are released when they break down in the water. Click on the photo right to see information about why these items are problematic.
Now, before you despair, go to the 6 Quick Solutions page to see what you can do, and then the Resources page to learn more.
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