Archive for July, 2014July 16, 2014
Cool streams on hot summer days draw children like a magnet. Children are out of school and seeking adventure. They see streams as an opportunity to explore, looking for stream critters or perhaps simply to cool off by wading in shallow water.
They are typically less aware of the potential physical, biological, and chemical hazards from runoff, failing septic systems, and broken sewer pipes. So what is the condition of our urban streams? Are they healthy and safe or simply storm sewer waterways to quickly discharge contaminated water to the major rivers? Approximately 25 volunteers, together with staff from the Iowa DNR, have sought to answer these questions.
The Polk County Snapshot volunteers go out on a designated day in the spring and fall, rain or shine, to perform field analyses, collect samples, and make field observations of the physical characteristics of the water and look for exposed or damaged pipes. They have been doing this since 2004, routinely collecting samples from 30 sites throughout the metro area to answer water quality observations.
The most recent snapshot was taken in May. The good news is that there is little evidence of direct fecal contamination from broken sewer, despite the more than a thousand miles of sewer pipe. There is little difference in fecal bacteria levels between rural and urban streams. During rainy weather with runoff, bacteria levels get very high in both urban and rural streams. During hot dry weather (when children most likely are exploring streams) bacteria levels are low (sewage from broken pipes would cause very high levels of bacteria during low stream flow because of less dilution by stream flow). Occasional high bacteria levels were observed in locations where yard wastes were raked into the stream. It is probable that pet droppings were included with the leaves. Urban streams differ slightly from rural streams following a small shower. In urban areas, roofs and streets create runoff to storm sewers and elevated bacteria levels in the stream while a light rain in rural area soaks into the ground with little runoff to carry fecal matter to the streams. During heavy rain, rural streams generally had higher bacteria levels. Livestock wastes are essentially untreated and often applied on the ground and not incorporated to reduce loss from runoff.
Nitrate and phosphorus concentrations are usually higher in rural streams. Exceptions occur during dry weather below the outfall from wastewater treatment plants. The concentrations decrease downstream because of dilution and biological activity including algae growth. Bacteria levels at these sites were low, indicating good biological treatment. Very high chloride concentrations (up to 10 times normal conditions) occurred at sites in the spring that implicated road salt as the source.
Arguably, the biggest threat to stream quality and public safety is flash flooding following a heavy rain. Storm sewers are designed to drain water from streets as quickly as possible. This greatly increases erosion leading to bank instability and a scouring of the stream bed. Redesigning storm water discharge structures and the creation of greenways should reduce this threat, improve habitat, and reduce erosion. Continued observations and stream monitoring will help determine the effectiveness of these activities.
We applaud the diligence of the stream guardians in protecting our urban streams, making them safer, healthier, and more attractive.
Hot, dry weather is upon us. By far, the highest water use during hot, summer days is for lawn or turf irrigation. There are many sophisticated automated, in-ground lawn sprinkler systems in use today; however, these systems require regular maintenance to operate efficiently. Even the most properly maintained system can be operated unwisely.
Des Moines Water Works, in cooperation with other Des Moines metro area water utilities, has developed the “Using Water Wisely” program. This is an educational, voluntary customer program aimed at reducing water use during hot, dry summer days. Customers can do this by eliminating lawn watering during the hottest part of the day (10:00 a.m. through 5:00 p.m.). This watering approach reduces the peak load on water facilities which extends their capacity and useful life. In addition, it is important to remember:
- Test irrigation systems each spring to ensure there are no leaking sprinkler heads and that each head is properly directing its spray onto the turf and landscape.
- For in-ground irrigation systems, install a moisture sensor that will turn off the irrigation system during its normal run cycle when there has been sufficient rainfall.
- When possible, avoid laying sod or grass seed during the month of July and the first three weeks of August. These typically are the hottest months of the year. New sod has no established root system and therefore requires daily watering during hot summer days to keep it alive. Beginning the last week in August and through the fall is the best time for laying sod and grass seed.
- Consult your preferred garden center, lawn or landscape professional for tips and consultation for your specific lawn and landscape care and watering needs.
Your “water bill” from Des Moines Water Works is actually a combined billing statement for water and services provided by the City of Des Moines. Some customers are surprised to learn that Des Moines Water Works is a municipality separate from the City of Des Moines. Des Moines Water Works is governed by a five- member Board of Water Works Trustees, and the City of Des Moines is governed by the City Council. While the Board of Water Works Trustees has oversight for setting policy and rates for water service, the Des Moines City Council has oversight for setting policy and rates for the city services of sanitary sewer, solid waste and storm water, which appear on your Des Moines Water Works bill.
The City of Des Moines (and other local communities served by Des Moines Water Works) contracts with Des Moines Water Works to perform the billing, collecting, and customer service for their municipal services. This collaboration is positive for customers, because it helps reduce redundancies in technologies and staff, and therefore keeps costs lower for customers. It can, however, be confusing. For the average residential customer who opens their water bill, it would be easy to mistakenly think “water” costs around $70.00 per month. In fact, in Des Moines, city services make up about $50.00 or 70% of the “water bill.” The remaining $20.00 per month represents the average customer’s true water charges – a price tag well below other utilities for which customers are paying, including electricity, gas, cable/satellite, cell phone, etc.
The Des Moines Water Works statement you receive each month includes a breakout of all the services for which you are being charged, and each section of the bill reflects whether it is a service provided by Des Moines Water Works or your city. Better understanding your monthly statement can help you better understand Des Moines Water Works’ commitment to delivering tap water that is safe, convenient, and affordable.