Renovation of a water / sewer project in Ventura, California. Conceptual plans call for the renovation of a water / sewer project.

The Casitas Municipal Water District is currently requesting proposals from competent and experienced firms in the area of pressure filter media removal and installation techniques for the purpose of inspection and media cleaning of pressure filter #1 at the Marion Walker Pressure Filtration Plant. It is Casitas' intent to receive proposals and cost statements that include all contractor services, including labor, materials, and equipment necessary to complete the work described in this request for proposal. The filtration plant is located at 1888 Casitas Vista Road, Ventura, California 93002. All work shall be performed in accordance with State, Federal and local County laws and codes. Furnish all material, labor, and equipment required to remove, clean, store and reinstall pressure filter media. The media shall be removed, cleaned and stored with equipment certified as safe for potable water or be otherwise approved by the District. Internal inspection of the pressure vessel will be performed by District personnel during the storage phase of this project. The following prints, pictures, and information are attached for reference: o VESSEL INTERNAL ASSEMBLY (Horizontal Media Filter) - ASY-9016-01-01 o PICTURES - (Pressure Filter #1 & 28" Access Manway) The scope of work for this project shall consist of the following elements: 1. Filter media shall be removed and reinstalled via the two 28" access manways located on the top of the pressure vessel. (see attached picture for reference) 2. Removal and installation of the anthracite and fine garnet filter media layers shall be performed hydraulically via the use of a (contractor provided) slurry eductor. Any potable water necessary for eductor operations will be supplied by Casitas via a hydrant (app. 80 psi) located at the worksite. A booster pump is required; it shall be supplied by the contractor. An appropriate spill containment area shall be setup to receive any process water associated with the media slurry processing. The suction of the pump shall be elevated above the media silt level in the containment area to prevent silt transfer over to the sludge beds. The resulting process water will be pumped by the contractor into the treatment plants existing sludge beds via the sludge process line. The remaining fines will be transported to the sludge beds by the contractor. 3. At the contractor's discretion, removal and installation of the coarse (support) garnet filter media layer shall be performed via the use an educator and/or industrial vacuum equipment. 4. Alternative methods for media removal and installation may be submitted by the contractor to the district for review and approval. Under no conditions, will the district approve any removal methods that permit media be to pass through a pump impeller. The District reserves the sole right to reject any alternative methods that are considered unacceptable. 5. The contractor shall remove the media in a manner that keeps the filter media differentiated. If the media becomes mixed as a result of the contractor's selected method of removal, the Contractor, at the Contractor's expense, shall separate the material. The Contractor shall remove the media in a way that will provide no more than 5% loss of the media. Replacement of any media in excess of 5% of the amount per media layer shall be at the contractor's own expense. 6. The filter media shall be stored on site in "semi bulk" bags having lifting loops and bottom discharge spout, weighing approximately 2,000-4,000 pounds each and shall be appropriately covered to prevent contamination. The maximum weight of each "semi bulk" bag shall not exceed 4,000 pounds. 7. Following the removal of the filter media, the district will perform an internal inspection of the pressure vessel. A fourteen (14) calendar day period (window) will be allowed for district personnel to inspect and perform any necessary repairs. In the event repairs are not required and/or the work is completed before the fourteen (14) day window ends, the contractor will be notified. 8. Upon completion of the media cleaning and the vessel internal inspection, the media will be re-installed by the contractor. Installation shall be in accordance with AWWA B100-0.1, except as modified herein. The coarse (support) garnet shall be placed first, followed by fine garnet and finally anthracite in graded layers that meet original specifications for each media type. Supplemental (new) media shall be added as necessary to ensure design depth of all media types. Prior to beginning the installation of each media layer, the contractor shall mark the final elevation of the respective media by a level line on the inside wall of the filter to ensure adequate depth and volume. The required specifications for media layer depths are found in the attached drawing: VESSEL INTERNAL ASSEMBLY (HORIZONTAL MEDIA FILTER) - ASY-9016-01-01 9. The coarse (support) garnet shall be carefully placed to avoid any damage to the existing filter underdrain laterals and shall be deposited in a uniform manner across the entire filter bed. Placement of the coarse garnet shall be performed in a single lift of approximately 13" of media. A backwash and surface scrape shall be performed following the installation of the media. The final depth of the coarse garnet shall be thirteen (13) inches after all necessary washing and surface scraping has been completed; proper depth of the media shall be achieved by screeding the filter media to the chalk line present on the interior filter wall. 10. The fine garnet and anthracite layers shall be placed and leveled in a manner similar to section 9 above. The contractor's workers shall not stand or walk directly upon the media, but upon clean, and disinfected boards or plywood that will support their weight without displacing or crushing the media. Placement of both the fine garnet and anthracite shall be performed in a series of two (2) "lifts" of approximately 9" of media. A backwash and surface scrape shall be performed by the contractor following each lift. The final depth of the fine garnet and anthracite media layers shall be eighteen (18) inches each after all necessary washing and surface scraping has been completed; proper depth of the media shall be achieved by screeding the filter media to the chalk line present on the interior filter wall. 11.In the event Casitas deems it necessary, proper depth of media layers shall be verified against a level water surface maintained at the appropriate elevation mark. 12.Thorough backwashing shall be completed after the installation of each media lift. Following each backwash, the surface of the filter media shall be cleaned (scraped) to remove all fines and foreign material that have accumulated. The District will operate all valves necessary to provide the backwashing. The contractor shall be responsible for all other actions including but not limited to securing the pressure vessel, cleaning the surface of the media, and reinstalling the filter media. The District requires a minimum two (2) hours' notice prior to each backwash in order to ensure adequate water availability and storage volume in the washwater reclaim system. 13.At completion of the filter media installation, the filter will be disinfected by Casitas staff in accordance with AWWA C653 standards. The method of Contractor Selection has not been Determined at this time.