RAINWATER HARVESTING

1. RAINWATER HARVESTING Presented by Jack Holmgreen SparkleTap Water Company

2. About SparkleTap Water Company • Incorporated in 1997, SparkleTap Water Company • Designs filtration systems for potable water • Engineers harvesting systems for rainwater • Stormwater management • Active in water purification, water conservation and rainwater harvesting fields for over twenty years. • Provide purified water for potable use in public buildings • Currently supply water for potable and non-potable uses.  Our projects have been funded by Economic Development Corporations, Water Districts and City Councils across Texas.  • Founding member of American Rainwater Catchment Systems Association (ARCSA) and are committed to the future of rainwater technology.

3. About SparkleTap Water Company (continued) • Level 3 Water Treatment Specialists licensed by the Texas Commission forEnvironmental Quality • Voting Member of the US Green Building Council (USGBC) • Rainwater Design Professionals certified by ARCSA • Member Irrigation Association

4. Stormwater Recycling and Rainwater Harvesting • Rainwater harvesting and stormwater recycling are similar processes • Rainwater harvesting involves collecting water from cleaner surfaces • Stormwater recycling is designed to collect ground level runoff • Both require collecting, storing, and conserving rainwater runoff specifically for use at a later date • Many commercial systems combine rooftop and surface runoff in the same storage facility

5. A Brief History of Rainwater Harvesting • Evidence suggests structures for holding rain water date back to 3,000 BC • Ancient cisterns have been discovered throughout the Mediterranean and Middle East • Native American rainwater harvesting systems can be found in Texas and Arizona • Rock cisterns in Texas known as the Hueco Tanks still remain • Tinajas in Arizona trapped rainwater for native dwellers

6. Why Harvest Rainwater Today? • Reasons for harvesting and reusing rainwater include: • Self-sufficient water supply located close to the user • Produces soft water with low mineral content • Recharge groundwater supplies while reducing soil salt content • Mitigation of urban flooding • Reduce erosion caused by flooding • Control water quality • Health concerns (DBP’s) • Pollution • Deteriorating municipal water infrastructure • Cost efficient

7. Components of a Rainwater Harvesting System • Before a rainwater harvesting system can be designed, several basic questions must be answered : • Retrofit existing building or use a new integrated system • System size – large, medium, or small • Complexity – passive, active or both • Cost – low cost or comprehensive • Intensity of use and level of commitment • Intended use – landscape irrigation and/or potable water. • Water quality required

8. Retrofitting a Rainwater Harvesting System • Retrofitting an existing building or landscape generally is more costly than designing a new, integrated system • System must be designed to fit intended use, site conditions and supply demands • Systems can range in size from small to very large. • Small: <5,000 gallons • Medium: 5,001 - 10,000 gallons • Large: 10,001 - 25,000 gallons • Very large: >25,000 gallons.

9. Types of Systems and Levels of Commitment • Systems can be complex or simple and active or passive • Complex systems can combine stormwater, greywater, potable and irrigation • Simple systems generally refer to landscape and infiltration only • Active systems require pipes, pumps, pressure tanks and filtration • Passive systems refer to use of drainage patterns, berms, basins and soil storage

10. Types of Systems and Levels of Commitment • Four types of rainwater harvesting systems including: • 1. Occasional: Small storage capacity, some of users needs met, alternate water source required, uniform rainfall areas with fewer days between rainfall. • 2. Intermittent: Small to medium storage capacity, users needs met for part of the year, may require alternate water source, single rainy season. • 3. Partial: Medium to large storage capacity provides all of high quality water needs and some non-potable needs for at least the historic dry season, dependable and uniform rainfall occurring in one or two wet seasons. • 4. Full: Large storage capacity, users needs met for the whole year, no alternate water source available, requires strict monitoring and regulated use of water supply.

11. Components of a Rainwater Harvesting System 1. Catchment area 2. Conveyance 3. Roof washing 4. Storage 5. Distribution 6. Purification

13. Water Budget Analysis • A water budget analysis allows a designer to: • Determine how much rainwater can be collected by the project catchment area, including rooftop and ground level areas • Provide a supply and demand analysis on a monthly basis • Size the cistern(s) • Determine how much, if any, supplemental water is needed • Redesign a project to increase or reduce catchment area or storage to meet water demands • Four items are required to prepare a water budget: • Average annual rainfall data • A site plan • A landscape plan • Occupancy data

15. Passive Rainwater Harvesting SystemsIntegrated Site Design • Integrated site design matches the site requirements with the collection components while improving the function and sustainability of the site • This process is based on a multidisciplinary approach • Evaluate opportunities to achieve multiple benefits • EXAMPLE: Above ground water tanks could provide stored water, shade, privacy screening, thermal mass and/or noise abatement

16. Passive Rainwater Harvesting SystemsIntegrated Site Design continued • The goal of integrated site management is to spread, slow and infiltrate the stormwater runoff. • Integrated site design manages stormwater runoff at the top of the watershed • Multiple small volumes of water can be infiltrated into the site, decreasing the volume of water that drains toward one place at the bottom of the site watershed where it's harder to collect and manage • On-site watershed can be divided into multiple small basins by using existing depressions or reshaping the topography as needed • Overflows directed to rain gardens, gabions, pollution catch basins

17. Passive Rainwater Harvesting SystemsIntegrated Site Design continued • Slowing and spreading the flow • Reduces erosion • Allows sediment and debris to drop out of the runoff, enriching soil in the water harvesting depressions. • Increasing soil surface area • Increases infiltration possibility • Allows water to be stored in the soil • The least expensive way to store stormwater • Stormwater stored in the soil should be in a location that supports plant life and does not damage built facilities • Areas where water is stored in the soil should be covered with a three to six inch layer of mulch to reduce evaporation and increase moisture retention • Excess water produced above the required needs can be directed to swales or infiltration fields

18. Slowly Infiltrate Runoff • There are several ways to slowly infiltrate runoff including the following: • Microbasins • Ditches on-contour • Swales off-contour • French drains • Gabions • Infiltration fields/ponds • Rainwater harvested in rain gardens can fully support native plants

19. Potable Rainwater Harvesting Systems • Collection of rainwater for potable uses is restricted to cleaner surfaces such as rooftops • The two most important components of potable collection: • Catchment surface • Metal roofs are preferred • Acceptable roofing also includes reinforced concrete, and plastic, fiberglass or composition shingles • Cement & clay tile is least desirable • Filtration • Clarification with floating intake • Cartridge pre-filter for sediment • Activated carbon for organics removal • Purification or disinfection for microbes

20. Rainwater for Human Consumption • Rainwater is slightly acidic, which means it will dissolve and carry minerals into the storage system • First step should be to test the water collected from a catchment surface to determine its content • Rainwater intended for human consumption should undergo several cleansing steps including: • Screening • Settling • Filtering • Disinfecting

21. Filtering Rainwater for Human Consumption • Filtering can include: • in-line or multi-stage cartridges • activated charcoal • reverse osmosis • chemical treatments • ultraviolet lights • ultra-filtration and/or ozonation • Water used from storage, • Sediment filtration should be a maximum of 5 micron sediment, followed by a nominal 0.5 micron carbon block filter or • An equivalent 1 micron absolute filter

22. Filtering Rainwater for Human Consumption • Micro filters will remove Giardia and Cryptosporidium • Should be approved by the NSF for cyst removal • Ultra Filters can remove bacteria and viruses • Ultraviolet irridation can be used for this application • Turbidity must be low and rated flow must be observed

23. Piping Design for Potable Systems • Only Schedule 40 PVC should be used • PE and polypropylene pipe is preferable • Coated aluminum, galvalum steel or plastic downspouts • No ABS and no DWV PVC pipe should be used • No recycled material should be used • No copper should be used

24. Conclusion • Begin by reducing demand through conservation • Use native, adaptive or xeriscape plant materials • Create raingardens, berms and micro basins • Use sub-surface irrigation • Use High Efficiency Toilets (HET) or Ultra Low Flow (ULF) toilets • Use front-loading clothes washer • Install flow restrictors in faucets and shower heads • Consider greywater for irrigation • Locate tank(s) for multiple benefits

25. Contact Information Jack Holmgreen SparkleTap Water Company 2951 Marina Bay Dr, Ste. 130-199 League City, TX 77573 email: jholmgreen@sparkletap.com http://www.sparkletap-rain.com 713-823-6126

28. Rainwater System Overview