Delano Municipal Utilities' Water System

The Present

Delano has four 150 foot deep ground water wells. The hardness of the water is 64 grains out of the ground. This is higher than average because most of Delano's water comes from deep aquifers.  The water is treated for iron and manganese removal by pressure filters at a rate of 5 million gallons per day (mgd). Chlorine is added to disinfect, fluoride is added for tooth protection, and polyphosphates are added reducing the hardness to 32 grains.

Delano's 1.5 million gallon storage tank built in 2002 replaced a 495,000 gallon built in 1970. The water distribution system consists of 20 miles of pipe, ranging from 4" in diameter to 16" with 351 hydrants that are flushed bi-annually for maintenance. The utility tests the water at numerous locations every month to ensure all state and federal water quality standards are met. Delano's water rates are among the lowest in the metro area. Click here to download the Public Drinking Water Report (you will need Adobe Acrobat Reader to view this file).

Water Treatment Groundwater has historically been assumed to be safe without treatment to kill microorganisms. Layers of soil act as a natural filter. Removing microbes and other particles as water seeps through. Groundwater is pumped from wells drilled into underground water reservoirs known as aquifers. The water undergoes a natural filtering process as it trickles through layers of soil and sand particles before collecting in the aquifers. Groundwater is more protected from environmental elements than surface water, meaning it requires fewer treatment and purifying steps. Some groundwater systems need to add a disinfectant like chlorine; others (such as those from particularly deep reservoirs) require no further treatment.

Safeguarding the Water Supply
Chlorine is the most common means of disinfecting water in the U.S. The addition of a small amount of chlorine is highly effective against most bacteria, viruses, and protozoa. But cysts (durable seed-like stages) formed by parasitic protozoa such as Cryptosporidium and Giardia can survive chlorine.

Mechanical failure can also lead to contamination. Water treatment facilities maintain constant water pressure in distribution pipes to prevent microbes from getting "backwashed" into the distribution system. Even a momentary lapse in pressure can result in a temporary backflow that can allow microbial contamination of already treated water.
 

Imagine if all the water that fell onto Delano in a single year stayed right where it landed. We would be wading through water higher than our waists! Fortunately, the 41 inches of average precipitation (both rain and snow) runs into the ponds, the Crow River or into underground storage areas called aquifers. Aquifers are underground reservoirs. The water that reaches these chambers is usually much cleaner than the water of reservoirs at the earth's surface. Almost no bacteria live in aquifers. Many pollutants are filtered out as the water passes through the soil on its way to the aquifer. Unlike surface reservoirs, there is no silty mud to cloud the water, no pollution from boaters, and no evaporation of the water supply by the sun. To tap the groundwater in an aquifer, wells are dug until they reach the top layer of the aquifer, the water table. The water table is not flat as its name makes it seem. It has peaks and valleys that echo the shape of the land above it. When a lot of water is pumped from an aquifer, or when there is a dry spell, the water table sinks lower.

Water flowing into recharge areas--land covered with soil and trees-- refills the aquifer. Bogs and swamps may absorb and store water that later slowly drains into aquifers. When recharge areas and wetlands are replaced by parking lots and highways, less water reaches the aquifer. Oil and road salt from paved roads may trickle down with rain and snowmelt and pollute an aquifer.

Sometimes an aquifer pops out the side of a hill as a spring. You can think of a spring as a newborn stream. Not many animals live in its water because it doesn't yet contain enough oxygen to support much life. Water mites, scuds or "sideswimmers," black fly or caddis fly larve, and occasionally beetles, snails, and salamanders may live in the cold water. Minks, raccoons, deer mice, and jays use springs as people do, for watering holes.

About seventy percent of the earth's surface is covered with water. Only one percent is fresh water, flowing through rivers, lakes, and underground streams. Much of that has already been polluted by humans. That is why aquifers and springs--natural sources of clean water-- are so important.

Who's in Charge?
All major water suppliers must comply with state and federal water safety regulations. (Different regulations apply to suppliers with fewer than 25 people or 15 connections a year.)

The Environmental Protection Agency (EPA) administers and enforces the two principal federal water safety laws: The Safe Drinking Water Act (SDWA) and the Clean Water Act (CWA).

The Safe Drinking Water Act protects water intended for consumption by setting standards and rules for levels of various pollutants that can contaminate water.

The Clean Water Act protects the nation's bodies of water, including rivers, lakes, and coastal zones. The Act regulates the discharge of pollutants into waters, and includes standards for wastewater (sewage) treatment.

This indirectly affects the safety of our drinking water, because the bulk of treated wastewater is released into rivers or other natural bodies of water, which in turn are often used as sources for drinking water.