2.3 PLANNING OBJECTIVES

This study addresses the following issues:

Based on a thorough evaluation, choose the best apparent alternative to meet

the City’s future needs based on cost and other key criteria. (page 6)

3.3 WASTEWATER TREATMENT

Design considerations regarding wastewater treatment plants should focus on meeting permit requirements, influent wastewater characteristics, and anticipated flows. General Design criteria are found in the Idaho Wastewater Rules (IDAPA 58.01.16.450) and are briefly summarized below:

� The WWTP design should have the ability to operate effectively within the range of expected waste characteristics and flows and meet NPDES permit requirements.

3.4 REGULATIONS

3.4.1 CLEAN WATER ACT

Under the CWA all discharges into a water body must be authorized by a permit.

Where is data for this table?

5.4.4 INFLOW AND INFILTRATION ANALYSIS

Flow approximations indicate that the Highway 93 collector gains an estimated 150 to 200 gpm of flow from I/I along its length. An additional estimated 100 gpm of I/I appears to enter the line along Lemhi Hole Road. The upper section of Shoup Street has an estimated I/I of 100 gpm in one line section.

5.8 FINANCIAL STATUS

As of 2008, the City of Salmon served 1,600 customer connections equaling approximately 2,123 equivalent dwelling units (EDUs). Sewer rates in Salmon were raised from $12 to $14 per month per EDU in 2007. A single family residential connection is considered to be a single EDU while multi-family and commercial connections are charged on an estimated EDU basis. Estimated sewer revenue for 2008 was $402,000 while operations and maintenance expenses were estimated to be $413,000. The sewer connection fee is $500 for a residential service line.

6.3.3 MEETING TREATMENT REQUIREMENTS

The Salmon Wastewater Treatment plant typically receives influent averaging 89.1 mg/L of TSS and 74.8 mg/L of BOD.

The very low influent wastewater concentrations directly affect the capability of the

wastewater treatment plant to achieve the NPDES discharge permit limits, specifically

the 85% removal requirement for BOD and TSS. When concentrations are low in the

influent wastewater, they must be reduced to very low levels to achieve an 85% removal

rate.

8.7 RECOMMENDED ACTION

The Lagoon Improvements Alternative ranks best of the viable alternatives in terms of capital and O&M cost, the parameters considered to be of highest importance in this analysis. With nutrient treatment unimportant to the decision, the only criterion this alternative ranks poorly on is expandability.

The lagoon improvements include the installation of a filtration system following the wastewater treatment lagoons, a headworks facility, and a lagoon cover for a portion of lagoon 2. As discussed in Section 8.5.2, several options for wastewater filtration are available. Selection of filter type and configuration should be included as part of the pre-design for the lagoon improvements project and further consideration should be given to the need for a lagoon cover. If a filter style that has proven capability for algae removal is selected, the lagoon cover will be unnecessary. These improvements yield a planning level cost estimate of $3,807,000.

The estimated costs of this alternative include:

� Wastewater Filter System - $ 2,175,000

� Headworks Facility - $ 399,000

� Lagoon Cover (or additional filter cost) - $ 1,233,000

Total Lagoon Improvements - $ 3,807,000

The cost estimate herein is based on our perception of current conditions at the project location. This estimate reflects our opinion of probable costs at this time and is subject to change as the project design matures. Keller Associates has no control over variances in the cost of labor, materials, equipment, services provided by others, contractor’s methods of determining prices, competitive bidding or market conditions, practices or bidding strategies. Keller Associates can not and does not warrant or guarantee that proposals, bids, or actual construction costs will not vary from the costs presented herein. The implementation of the Lagoon Improvements Alternative will address the shortfalls in the wastewater treatment process to meet the percent removal requirements for BOD and TSS. In conjunction with this alternative, several other actions should be taken to address peripheral issues, including:

- Removal of sludge from wastewater lagoons - Replacement of UV Disinfection System - Repair/Replacement of Collapsed Pipe Sections

- Collection System Improvements to reduce I/I

As discussed in Section 5.6.2, sludge accumulation in the wastewater lagoons is approaching levels that could seriously impact the treatment capability of the lagoons. It is recommended that the lagoon sludge be removed within the next few years.

The failing state of the UV disinfection units as discussed in Section 5.6.3 is a critical issue that must be addressed as soon as possible. As mentioned previously, the City of Salmon has already begun the process of replacing one of the units. The second unit should also be replaced as soon as possible.

The two collapsed sections of collection system piping identified during the June 2009 CCTV inspection. These two portions of collapsed pipe should be replaced/repaired at the earliest possible time. The City has already begun planning to replace the collapsed section of the Highway 93 line.

As discussed in Sections 5.2 and 5.4.5, the collection system experiences a large amount of infiltration and inflow (I/I). If infiltration and inflow increases by as little as 1% annually, the peak month flow could begin to exceed the estimated treatment capacity of the lagoon system. Collection system improvements are necessary to reduce I/I to mitigate the possibility of exceeding the capacity of the treatment plant