Water Industry News

PRASA has ample water supplies

By Ferdinand Quinones, PE
Technical Manager of the Office of the Water Plan to
Puerto Rico Aqueduct and Sewer Authority (PRASA) and Department of Natural and Environmental Resources (DNER)  

  1. Puerto Rico has ample water even during droughts.  The average annual precipitation over the Island is 69 inches per year, with several basins receiving as much as 100 inches a year.  We estimate that under the worst case scenario of a 100-year drought, the streams and aquifers in the Island, combined with the storage in 32 public reservoirs, can deliver easily 500 million gallons per day (mgd’s).  Look at the islands water budget in the web page.
  1. Total fresh water use in the Island in 2002 was about 723 mgd, including domestic (PRASA), industrial, agricultural, business and government. PRASA produced 576 mgd in 2002 to serve 3.8 million people, at a tune of 151 gallons per person per day (gppd).   Actual consumption is estimated at about 85 gppd.  Therefore, PRASA looses about 43% of its production to leaks and waste.  Losses have increased from less than 20 % in 1960 to the current 43 %.
  1. PRASA serves the highest percentage of people in their service area than any other single utility in the world (3.8 of the 3.91 population of the island).  About 125,000 people rely on Non-PRASA private systems that do not meet the Federal Potable Water criteria.  PRASA recently financed a $550K study of these systems to develop strategies to bring them into compliance, since EPA is looking at sanctions to force them to comply with drinking water standards.
  1. The real issues on the water problems in the island are related some to the labor problems, but the main issues are the lack of resources and long-term planning due to political intervention with PRASA management.  These are the true facts from the results of the Water Plan:
    1. If potable water losses are reduced from 43% to 25% of production, the Island would not need much additional infrastructure for the next 15 years, except in certain regions, particularly the Southwest and the Central Region.
    1. The average annual cycle of the Island shows that there is enough runoff to produce at least twice as much water as PRASA produces now.  Reducing the losses to a manageable level establishes that there is a potential to supply 3-4 times the island’s current population.  This translates to decades if not hundred of years of supplies.
    1. Storage of runoff is a major issue, since the reservoirs, which supply 370 mgd to PRASA, are relatively small.  In most of the island’s basins, extractions of raw water is less than 30 % of average basin production.  Even so, the current storage systems can easily meet the demand of a 90-day drought, even with the current levels of losses.  Additional reservoirs are now under consideration to improve storage and service.
    1. True that thousands of families have poor service and low pressures.  This is related to a combination of factors:

i.       Population growth of 1% per year in the Island has resulted in urban sprawl into the rural areas that is taxing PRASA's supply and distributions systems ahead of plans and construction.  Plant capacities are partially inadequate to meet the demand. 

ii.      In the Central and East Central Regions, where most of these problems occur, even although the average rainfall on the hills is almost 100 inches a year, the filtration plants are not well equipped to deal with high turbidities each time it rains a lot. Production is reduced or shut down.  Lack of adequate storage for finished water compounds the problem, since the systems do not have enough time to recuperate each time the plants go down due to high turbidity.  Empty or partially filled tanks result in low pressures and reduced service.  Lack of proper maintenance and labor problems compound this issue. 

iii.     In the Southern and Southeast regions, water supplies are more limited than in the other regions due to limited rainfall, problems with the aquifers, limited infrastructure and competition for the water with agriculture and power generation.  PRASA’s efforts to expand production have been slowed down by private interests in agriculture and environmental groups unhappy with the losses in the systems.



The solutions to the problem are going to take years and cost tons of money.  PRASA just finished a Master Infrastructure Plan to year 2030, and jointly with the Water Management Plan, we see the end of the tunnel.  Actions that will be required in the next 3-5 years and beyond: 

  1. Improve PRASA’s balance sheet.  PRASA’s water and sewage rates are the lowest among 50 of 51 similar utilities in the USA and Canada. There are no incentives for water conservation (or penalties for waste).  This is a political issue.  PRASA’s operational budget runs a deficit in excess of $200 million a year and infrastructure funds are limited by the Commonwealth finances.
  1. Reduce losses to not more than 30 % in 5 years and 25 % in 10 years.  PRASA is organizing an Office of Water Loss to press forward with an intense effort to reduce losses.  Tons of money will be required for replacement of pipes and leaky fire hydrants.  Continuous leakage detection programs will be implemented.
  1. Improve raw and finished water storage.  Additional reservoirs are needed to deal with droughts and critical areas in the south and southwest.  Additional storage tanks are needed to stabilize water pressures in many systems.  PRASA’s infrastructure plan addresses these needs.  This will cost lots of money too.
  1. Centralize water management with the DNER.  Several agencies now have control of water resources, with conflicts.  A legal study as part of the Water Plan will identify strategies to address the water management issues.
  1.  The aquifers have been perceived as a huge water source, which is incorrect.  Although significant, they can yield only about 150 mgd of sustained withdrawals if conditions were favorable, but they are a mess, with saline intrusion, overdraft and contamination.  Extreme measures will be required to restore them to maintain a 100 mgd production for now, and there is the potential that this will be reduced.  An aquifer restoration program is proposed, and as part of it, PRASA recently authorized an initial recharge viability study in the south coast.
  1. Wastewater reuse offers a potential for some relief, particularly in the industrial sector and for restoration of aquifers.  The Water Plan identifies opportunities for reuse.  PRASA and the AEE are collaborating in some reuse programs.
  1. Desalination also offers a potential for some relief, but energy costs and maintenance present reality obstacles.  Electric power in the island is very expensive, and desalination is still very expensive even with RO technology as compared with surface and ground resources in the Island.  The Plan identifies opportunities for RO and other desalination issues.
  1. Supplying water in a reliable manner to a society of 3.9 million in an Island of 3,345 square miles where more than half of the terrain is steep and hilly, with thousands of pumping stations, 15,000+ kilometers of transmission lines, 105 filtration plants under one utility with 5,000 employees, is no piece of cake. 

I believe that PRASA has now an excellent management team that, if allowed by the politicians to run the utility as a business, we will see significant improvements in a relative short time.  Providing water to every citizen in the Island that chooses to live in isolated communities where each connection may cost as much as $100,000, is not a task that neither PRASA nor any utility can achieve.  PRASA is doing well for 90-95% of the people, and will do better in the next few years if the Water Plan and the Water Infrastructure Plan are implemented.  The Water Management Plan will be published early in 2005 for review and public hearings, with plans for adoption within a few months. The new management at PRASA is moving quickly to implement elements of the Infrastructure Plan subject to availability of funds.  A copy of the Water Management Plan for the Island will be available in the indicated web page as early as mid January 2005.